DE102023209354A1 - Flexible waveguide - Google Patents

Abstract

Embodiments provide a flexible waveguide [e.g. for guiding at least one high-frequency signal, e.g. with a frequency greater than or equal to 0 Hz], having the following features: a first metallization [e.g. first shielding metallization], a second metallization [e.g. second shielding metallization], a flexible substrate arranged between the first metallization and the second metallization, and a center conductor [e.g. inner conductor] embedded in the flexible substrate, wherein the center conductor comprises at least two striplines, wherein at least one stripline of the at least two striplines comprises a superconducting material.

Description

Embodiments of the present invention relate to a flexible waveguide. Some embodiments relate to a miniaturized flexible waveguide. Some embodiments relate to a quantum computer with a flexible waveguide.

In cryogenic applications, such as quantum computers with superconducting qubits, commercially available coaxial waveguides have been used to transmit RF signals [1]. Semi-rigid coaxial cables are typically used. This requires a connector for each cable, in addition to numerous cables. With a higher number of qubits, the space required by the cables exceeds the available space in the cryostat. Furthermore, the passive heat input from the cables increases with the number of cables.

Furthermore, flexible multi-core cables with superconducting inner conductors are known from [2]. Furthermore, flexible cables with an integrated low-pass filter are known from [3]. However, these can only be used at cryogenic temperatures and, due to the high attenuation at room temperature, are not suitable for connecting to signal generators and/or signal analyzers operating at room temperature in cryogenic applications.

The present invention is therefore based on the object of creating a concept which makes it possible to reduce the space required for the cables and at the same time to keep the attenuation low over the required wide temperature range (e.g. from cryogenic to room temperature).

This problem is solved by the independent patent claims.

Advantageous further developments can be found in the dependent patent claims.

Embodiments provide a flexible waveguide [e.g., for carrying at least one high-frequency signal, e.g., with a frequency greater than or equal to 0 Hz], comprising: a first metallization [e.g., first shielding metallization], a second metallization [e.g., second shielding metallization], a flexible substrate disposed between the first metallization and the second metallization, and a center conductor [e.g., inner conductor] embedded in the flexible substrate, wherein the center conductor comprises at least two striplines, wherein at least one stripline of the at least two striplines comprises a superconducting material.

For example, the flexible waveguide can be configured as a ribbon cable. In particular, the flexible waveguide can have a plurality of center conductors.

In embodiments, a first stripline of the at least two striplines comprises a first superconducting material, wherein a second stripline of the at least two striplines comprises a second superconducting material.

In embodiments, the first superconducting material and the second superconducting material are two different materials.

In embodiments, a first stripline of the at least two striplines comprises a superconducting material, wherein a second stripline of the at least two striplines comprises a non-superconducting material.

In embodiments, the non-superconducting material does not exhibit superconducting properties at any temperature.

In embodiments, the superconducting material exhibits superconducting properties at temperatures below a material-specific transition temperature.

In embodiments, the superconducting material may be one of the following materials: niobium, aluminum, lead, indium, zinc, tantalum, or niobium nitride.

In embodiments, the non-superconducting material may be one of the following materials: copper, nickel, gold, or silver.

In embodiments, the at least two striplines run parallel [e.g., with a constant distance] to each other.

In embodiments, the at least two striplines are connected to each other [e.g., mechanically and/or electrically].

In embodiments, the at least two striplines are directly [i.e., without an adhesion layer and/or without a diffusion barrier] [mechanically and/or electrically] connected to one another.

In embodiments, at least two striplines are connected to one another [mechanically and/or electrically] by means of an adhesion layer [e.g., titanium (Ti), titanium-tungsten (Ti-W), chromium (Cr)] and/or by means of a diffusion barrier [e.g., titanium dioxide (TiO2) or titanium nitride (TiN)].

For example, stacking two metal layers typically does not require an adhesion layer between the metal layers, as metal-to-metal adhesion provides good adhesion. However, for some metal combinations, a diffusion barrier [e.g., titanium dioxide (TiO2) or titanium nitride (TiN)] is required between them to prevent the formation of an alloy between the two metals.

In embodiments, the metal of the center conductor and/or the first metallization and/or the second metallization can be bonded to the substrate [e.g., polymer substrate] by means of an adhesion layer [e.g., titanium (Ti), titanium-tungsten (Ti-W), chromium (Cr), ...]. Depending on the metal, however, the adhesion layer may also be omitted.

In embodiments, a third stripline of the at least two striplines comprises a superconducting material, wherein the second stripline is arranged between the first stripline and the third stripline.

For example, the first stripline may comprise copper, the second stripline may comprise niobium, and the third stripline may comprise copper.

In embodiments, a third stripline of the at least two striplines comprises a non-superconducting material, wherein the first stripline is arranged between the second stripline and the third stripline.

For example, the second stripline may comprise niobium, the first stripline may comprise copper, and the third stripline may comprise niobium.

In embodiments, the second stripline is embedded between the first stripline and the third stripline.

In embodiments, the first stripline is embedded between the second stripline and the third stripline.

For example, the three striplines may be implemented by three material layers, with one of the three material layers being embedded between two other of the three material layers.

In embodiments, the first metallization and/or the second metallization each comprise at least two metallization layers, wherein at least one metallization layer of the at least two metallization layers comprises a superconducting material.

In embodiments, a first metallization layer of the at least two metallization layers comprises a first superconducting material, wherein a second metallization layer of the at least two metallization layers comprises a second superconducting material

In embodiments, a first metallization layer of the at least two metallization layers comprises a superconducting material, wherein a second metallization layer of the at least two metallization layers comprises a non-superconducting material.

In embodiments, the flexible substrate comprises polyimide.

In embodiments, a first distance between the center conductor and the first metallization is smaller or larger than a second distance between the center conductor and the second metallization.

In embodiments, the first metallization and the second metallization are connected to one another via a plurality of vias [e.g., electrically].

In embodiments, the plurality of vias each comprise two via layers [e.g., extending perpendicularly with respect to the first and/or second metallization], wherein a first via layer of the two via layers comprises a superconducting material, and wherein a second via layer of the via layers comprises a non-superconducting material.

In embodiments, the center conductor is a first center conductor, wherein the flexible waveguide has a second center conductor arranged spaced apart from the first center conductor [e.g., parallel or vertically offset from the first center conductor].

In embodiments, the second center conductor is embedded in the flexible substrate.

In embodiments, the second center conductor can be structured/constructed identically to the first center conductor. In particular, the second center conductor can comprise at least two striplines, wherein at least one of the at least two striplines comprises a superconducting material. For example, a first stripline can comprise a first superconducting material, while a second stripline comprises a second superconducting material, wherein the first superconducting material and the second superconducting material are different. Of course, a first stripline of the at least two striplines can also comprise a superconducting material, wherein a second stripline of the at least two striplines can comprise a non-superconducting material.

In embodiments, the first center conductor and the second center conductor are arranged in the substrate next to each other with respect to the first and/or second metallization [e.g., with respect to a straight line running parallel to the first and/or second metallization] [e.g., such that the first center conductor and the second center conductor intersect a straight line [e.g., at different points] running parallel to the first and/or second metallization].

For example, the first center conductor and the second center conductor may have the same distance to the first and/or second metallization [e.g., and different distances to the plurality of vias.

In embodiments, the first center conductor and the second center conductor are arranged one above the other in the substrate with respect to the first and/or second metallization [e.g., with respect to a straight line perpendicular to the first and/or second metallization] [e.g., such that the first center conductor and the second center conductor intersect a straight line [e.g., at different points] perpendicular to the first and/or second metallization].

For example, the first center conductor and the second center conductor may have different distances to the first and/or second metallization [e.g., and have equal distances to the plurality of vias].

In embodiments, the first center conductor and the second center conductor are connected to each other [e.g., electrically] via at least one via.

In embodiments, the substrate is a first substrate, wherein the flexible waveguide comprises a second substrate and a third metallization [e.g., third shield metallization], wherein the second substrate is disposed between the second metallization and the third metallization, wherein the second center conductor is embedded in the second substrate.

Further embodiments provide a quantum computer having the following features: a quantum processor, a signal generator and/or signal evaluator, and at least one flexible waveguide according to one of the embodiments described herein for signal transmission between the quantum processor and the signal generator and/or signal evaluator.

In embodiments, the quantum processor is configured to operate at a cryogenic temperature [e.g., a temperature of less than 1 K].

In embodiments, the signal generator and/or signal evaluator is configured to operate at a cryogenic temperature [e.g., a temperature of less than 1 K] or a non-cryogenic temperature [e.g., a temperature of more than 253 K].

In embodiments, the flexible waveguide may have a pad, wherein the pad is arranged in a plane of the first metallization and is [e.g., electrically] insulated from the first metallization, wherein the pad is [e.g., electrically] connected to the center conductor [e.g., via one or more vias].

In embodiments, the flexible waveguide may include a plurality of vias arranged such that the plurality of vias surround the center conductor and the pad.

In embodiments, the flexible waveguide may have a first pad and a second pad, wherein the first pad and the second pad are arranged in a plane of the first metallization and are isolated from the first metallization [e.g., electrically], wherein the first pad is connected to the first center conductor and the second pad is connected to the second center conductor [e.g., electrically].

In embodiments, the flexible waveguide may include a plurality of vias, wherein the plurality of vias are arranged such that the plurality of vias surround the first center conductor and the first pad, surround the second center conductor and the second pad, and shield the first center conductor and the first pad from the second center conductor and the second pad.

In embodiments, the first terminal surface and the second terminal surface may be arranged adjacent to an end of the flexible waveguide, wherein the first terminal surface and the second terminal surface have different distances from the end of the waveguide.

Further embodiments provide a satellite having the following features: at least one external antenna, a transmitting and/or receiving device, and at least one waveguide according to one of the embodiments described herein for signal transmission between the at least one external antenna and the transmitting and/or receiving device.

Further embodiments provide a motor vehicle having the following features: a control unit, a sensor, and at least one waveguide according to one of the embodiments described herein for signal transmission between the control unit and the sensor.

Further embodiments provide a method for producing a flexible waveguide. The method comprises a step of providing a first layer of a flexible substrate. The method further comprises a step of providing a center conductor on the first layer of the flexible substrate, wherein the center conductor comprises at least two striplines, and wherein at least one stripline of the at least two striplines comprises a superconducting material. The method further comprises a step of providing a second layer of the flexible substrate on the first layer of the flexible substrate and the center conductor, such that the center conductor is embedded between the first layer of the flexible substrate and the second layer of the flexible substrate. The method further comprises a step of providing a first metallization and a second metallization, wherein the first metallization is provided on a first side of a stack of the first layer of the flexible substrate and the second layer of the flexible substrate, and wherein the second metallization is provided on a second side of the stack opposite the first side.

In embodiments, providing the center conductor comprises providing an adhesion layer and/or a diffusion barrier between the first stripline and the second stripline.

In embodiments, the method further comprises a step of providing a plurality of vias between the first metallization and the second metallization [e.g., wherein the vias [e.g., electrically connect] the first metallization and the second metallization to each other].

Further embodiments provide a method for producing a flexible waveguide. The method comprises a step of providing a first layer of a flexible substrate of the flexible waveguide. The method further comprises a step of forming at least one hole through the first layer of the flexible substrate. The method further comprises a step of coating both sides of the first layer of the flexible substrate with a first metallization [e.g., by sputtering, thermal vapor deposition, or electroplating], wherein, during the both-sided coating, side walls of the at least one hole are coated with the first metallization to obtain at least one via. The method further comprises a step of structuring [e.g., by a combination of photolithography and etching [e.g., wet chemical and/or plasma-assisted] the first metallization in order to obtain a center conductor of the flexible waveguide on a first side of the first layer of the flexible substrate and to obtain a connection area for electrically contacting the center conductor on a second side of the first layer of the flexible substrate facing away from the first side, wherein the connection area and the center conductor are electrically connected to one another via the at least one via. The method further comprises a step of providing a second layer of the flexible substrate on the first side of the first layer of the flexible substrate. The method further comprises a step of forming a plurality of holes through the first layer and the second layer of the flexible substrate. The method further comprises a step of coating the flexible substrate on both sides with a second metallization, wherein, during the double-sided coating, side walls of the plurality of holes are coated with the second metallization in order to obtain a plurality of vias. Furthermore, the method comprises a step of structuring the second metallization to obtain a first shielding metallization of the flexible waveguide.

In embodiments, the first metallization may comprise at least two first metallization layers, wherein a first layer of the at least two first metallization layers comprises a superconducting material, and wherein a second layer of the at least two first metallization layers comprises a non-superconducting material.

In embodiments, the second metallization may comprise at least two second metallization layers, wherein a third layer of the at least two second metallization layers comprises a superconducting material, and wherein a fourth layer of the at least two second metallization layers comprises a non-superconducting material.

In embodiments, the plurality of vias may be arranged such that the plurality of vias surround the center conductor and the pad.

In embodiments, the center conductor may be a first center conductor, wherein the pad is a first pad, wherein a second center conductor and a second pad are formed during patterning of the first metallization, wherein the second center conductor and the second pad are connected to each other via a via, wherein the plurality of vias are arranged such that the plurality of vias surround the first center conductor and the first pad, surround the second center conductor and the second pad, and shield the first center conductor and the first pad from the second center conductor and the second pad.

In embodiments, the first connection surface and the second connection surface may have different distances from one end of the waveguide in the wave propagation direction of the flexible waveguide.

• 1a eine schematische Schnittansicht durch einen flexiblen Wellenleiter quer zur Wellenausbreitungsrichtung, gemäß einem Ausführungsbeispiel,
• 1b eine schematische Schnittansicht durch einen flexiblen Wellenleiter längs zur Wellenausbreitungsrichtung, gemäß einem Ausführungsbeispiel,
• 2 eine schematische Schnittansicht durch einen flexiblen Wellenleiter quer zur Wellenausbreitungsrichtung, gemäß einem Ausführungsbeispiel,
• 3a eine schematische Schnittansicht durch einen flexiblen Wellenleiter quer zur Wellenausbreitungsrichtung, wobei der Wellenleiter einen Mittelleiter mit zwei Streifenleitungen als Supraleiter und Normalleiter aufweist, gem. einem Ausführungsbeispiel,
• 3b eine schematische Schnittansicht durch einen flexiblen Wellenleiter quer zur Wellenausbreitungsrichtung, wobei der Wellenleiter einen Mittelleiter mit drei Streifenleitungen als Supraleiter und Normalleiter aufweist, gemäß einem Ausführungsbeispiel,
• 4a in einem Diagramm einen Verlauf der simulierten Einfügungsdämpfung in dB eines flexiblen Wellenleiters mit Supra- und Normalleiter aufgetragen über die Frequenz in GHz,
• 4b in einem Diagramm einen Verlauf der simulierten Einfügungsdämpfung in dB eines Niobwellenleiters aufgetragen über die Frequenz in GHz,
• 5 eine schematische Schnittansicht durch einen flexiblen Wellenleiter quer zur Wellenausbreitungsrichtung, wobei der flexible Wellenleiter zwei Mittelleiter aufweist, die in unterschiedlichen Substraten eingebettet sind, gemäß einem Ausführungsbeispiel,
• 6a eine schematische Schnittansicht durch einen flexiblen Wellenleiter quer zur Wellenausbreitungsrichtung, wobei der flexible Wellenleiter zwei nebeneinander angeordnete Mittelleiter aufweist, gemäß einem Ausführungsbeispiel,
• 6b eine schematische Schnittansicht durch einen flexiblen Wellenleiter quer zur Wellenausbreitungsrichtung, wobei der flexible Wellenleiter zwei übereinander angeordnete Mittelleiter aufweist, gemäß einem Ausführungsbeispiel,
• 7 eine schematische Schnittansicht durch einen flexiblen Wellenleiter quer zur Wellenausbreitungsrichtung, wobei der flexible Wellenleiter zwei übereinander angeordnete Mittelleiter aufweist, die über Vias miteinander verbunden sind, gemäß einem Ausführungsbeispiel,
• 8 eine schematische Schnittansicht quer zur Wellenausbreitungsrichtung eines Mittelleiters mit drei Streifenleitungen, wobei eine erste Streifenleitung zwischen einer zweiten Streifenleitung und einer dritten Streifenleitung eingebettet ist, gemäß einem Ausführungsbeispiel,
• 9 ein Flussdiagramm eines Verfahrens zur Herstellung eines flexiblen Wellenleiters, gemäß einem Ausführungsbeispiel,
• 10a-g schematische Schnittansichten des flexiblen Wellenleiters nach unterschiedlichen Schritten eines Herstellungsverfahrens zum Herstellen des flexiblen Wellenleiters, gemäß einem Ausführungsbeispiel,
• 11 eine schematische Ansicht von Anschlussflächen des flexiblen Wellenleiters, gemäß einem Ausführungsbeispiel,
• 12 ein schematisches Blockschaltbild eines Quantencomputers, gemäß einem Ausführungsbeispiel, und
• 13 ein schematisches Blockschaltbild eines Satelliten mit einem flexiblen Wellenleiter, gemäß einem Ausführungsbeispiel.

Embodiments of the present invention are described in more detail with reference to the accompanying figures. They show:

• 1a a schematic sectional view through a flexible waveguide transverse to the wave propagation direction, according to an embodiment,
• 1b a schematic sectional view through a flexible waveguide along the wave propagation direction, according to an embodiment,
• 2 a schematic sectional view through a flexible waveguide transverse to the wave propagation direction, according to an embodiment,
• 3a a schematic sectional view through a flexible waveguide transverse to the wave propagation direction, wherein the waveguide has a center conductor with two striplines as superconductors and normal conductors, according to an embodiment,
• 3b a schematic sectional view through a flexible waveguide transverse to the wave propagation direction, wherein the waveguide has a center conductor with three striplines as superconductors and normal conductors, according to an embodiment,
• 4a in a diagram a curve of the simulated insertion loss in dB of a flexible waveguide with superconductor and normal conductor plotted against the frequency in GHz,
• 4b in a diagram a curve of the simulated insertion loss in dB of a niobium waveguide plotted against the frequency in GHz,
• 5 a schematic sectional view through a flexible waveguide transverse to the wave propagation direction, wherein the flexible waveguide has two center conductors embedded in different substrates, according to an embodiment,
• 6a a schematic sectional view through a flexible waveguide transverse to the wave propagation direction, wherein the flexible waveguide has two center conductors arranged side by side, according to an embodiment,
• 6b a schematic sectional view through a flexible waveguide transverse to the wave propagation direction, wherein the flexible waveguide has two center conductors arranged one above the other, according to an embodiment,
• 7 a schematic sectional view through a flexible waveguide transverse to the wave propagation direction, wherein the flexible waveguide has two center conductors arranged one above the other, which are connected to one another via vias, according to an embodiment,
• 8 a schematic sectional view transverse to the wave propagation direction of a center conductor with three striplines, wherein a first stripline is embedded between a second stripline and a third stripline, according to an embodiment,
• 9 a flowchart of a method for producing a flexible waveguide, according to an embodiment,
• 10a -g schematic sectional views of the flexible waveguide after different steps of a manufacturing method for producing the flexible waveguide, according to an embodiment,
• 11 a schematic view of connection surfaces of the flexible waveguide, according to an embodiment,
• 12 a schematic block diagram of a quantum computer, according to an embodiment, and
• 13 a schematic block diagram of a satellite with a flexible waveguide, according to an embodiment.

In the following description of the embodiments of the present invention, identical or equivalent elements in the figures are provided with the same reference numerals so that their description is interchangeable.

1. Flexible waveguide

The (highly integrated) flexible waveguide described below enables the transmission of a wide range of high-frequency signals in a small space and with a small cross-section. This can both solve the space problem and reduce (or even minimize) the passive heat input through the cables.

1a shows a schematic sectional view through a flexible waveguide 100 transverse (perpendicular) to the wave propagation direction, while 1b shows a schematic sectional view through the flexible waveguide along the wave propagation direction, according to one embodiment. The waveguide 100 comprises a first metallization 102 (e.g., first shielding metallization), a second metallization 104 (e.g., second shielding metallization), a flexible substrate 106 arranged between the first metallization 102 and the second metallization 104, and a center conductor 108 (or inner conductor) embedded in the flexible substrate 106. The center conductor 108 comprises at least two striplines 110_1, 110_2, wherein at least one of the at least two striplines comprises a superconducting material.

In embodiments, a first stripline 110_1 of the at least two striplines 110_1, 110_2 may comprise a first superconducting material, wherein a second stripline 110_2 of the at least two striplines 110_1, 110_2 may comprise a second superconducting material, wherein the first superconducting material and the second superconducting material are different.

The first superconducting material and the second superconducting material can be two different superconducting materials from the superconducting materials listed in Table 1, such as niobium and aluminum, niobium and lead, or niobium and aluminum. It should be noted that the two different superconducting materials are not limited to a specific material combination; rather, the superconducting materials listed in Table 1 can be arbitrarily combined. In other words, any of the superconducting materials listed in Table 1 can be combined with any other superconducting material listed in Table 1.

In embodiments, a first stripline 110_1 of the at least two striplines 110_1, 110_2 may comprise a superconducting material, wherein a second stripline 110_2 of the at least two striplines 110_1, 110_2 may comprise a non-superconducting material.

The superconducting material can be any superconducting material listed in Table 1, while the non-superconducting material can be any non-superconducting material listed in Table 2. For example, the superconducting material can be one of niobium, aluminum, lead, indium, zinc, tantalum, and niobium nitride, while the non-superconducting material can be one of copper, gold, and silver. It should be noted that the superconducting material and the non-superconducting material are not limited to any specific material combination; rather, the superconducting materials listed in Table 1 and the non-superconducting materials listed in Table 2 can be arbitrarily combined. In other words, any of the superconducting materials listed in Table 1 can be combined with any non-superconducting material listed in Table 2.

In addition to the superconducting materials, Table 1 below also lists the transition temperatures, i.e., the temperatures above which the respective materials become superconducting. Table 1: Superconducting materials and transition temperatures [4] element symbol Transition temperature Solid state normal pressure If the condition specified in brackets is met aluminum Al 1.18 K 3.6K (movie) Americium On 1 K beryllium Be 0.026 K 9.5K (movie) cadmium CD 0.52 K gallium Ga 1.08 K 8.6K (movie) hafnium Hf 0.38 K mercury Hg 4.15 K Indium In 3.4 K 4.2K (movie) iridium Ir 0.1 K Carbon nanotube 15K Lanthan La 6 K 12.8 K (20 GPa) lutetium Lu 0.1 K 1.2 K (18 GPa) molybdenum Mon 0.92 K niobium Nb 9.25K 9.7 K (4.5 GPa) osmium Os 0.7 K Protactinium Pa 1.4 K Lead Pb 7.2 K rhenium re 1.7 K Rhodium Rh 0.000 035 K Ruthenium Ru 0.5 K tin Sn 3.7 K 4.7K (movie) Tantal Ta 4.4 K 4.5 K (40 GPa) Technetium Tc 8.2 K Thorium Th 1.4 K titanium Ti 0.5 K Thallium Tl 2.4 K uranium U 1.3 K 2.2 K (1 GPa) Vanadium V 5.4K 17.2 K (120 GPa) tungsten W 0.01 K 5.5K (movie) zinc Zn 0.85 K 1.6K (movie) Zirconium Zr 0.6 K 11 K (30 GPa)

Non-superconducting materials are listed in Table 2 below. Table 2: Non-superconducting materials element symbol Gold Au copper Cu nickel No Silver Ag

In embodiments, the other metallizations (e.g. first metallization, second metallization and/or a plurality of vias (cf. 3a and 3b) each having two layers, wherein at least one of the two layers comprises superconducting material.

In embodiments, the substrate may comprise a polymer, such as polyimide.

According to exemplary embodiments, suitable waveguides for high-frequency signals can be manufactured based on (polyimide) films or (polyimide) substrates coated with various metals (e.g., copper, niobium, aluminum, etc.). If the substrate is coated with superconducting materials (e.g., niobium or aluminum), superconducting cables can also be constructed. In exemplary embodiments, a waveguide, such as a stripline, is realized with at least three metal layers.

In embodiments, the substrate is implemented using a flexible material such as polyimide or thin polyimide films, whereby the entire waveguide is flexible within certain limits and can be used and bent in a similar way to a cable.

By appropriately placing vias at regular intervals, a sufficiently high shielding attenuation can be achieved, so that even with adjacent waveguides, the decoupling is less than -60 dB or less. These so-called via fences can be arranged singly, doubled, or n-fold in series to achieve even lower crosstalk, where n is a natural number greater than or equal to one. In the case of multi-row vias, In order to achieve even higher signal integrity, via fences can also be offset from each other; for example, by half a via grid.

With suitable dimensioning and sufficient manufacturing tolerances and capabilities, a very highly integrated and flexible cable with multiple waveguides can be realized, such as 100 waveguides per inch.

2 shows a schematic sectional view through a flexible waveguide transverse to the wave propagation direction, according to an embodiment. In other words, 2 shows a cross-section of a flexible waveguide (e.g. flexible cable) with several indicated lines and three metal layers. As already mentioned with regard to 1a and 1b As described, the waveguide 100 includes a first metallization 102, a second metallization 104, a flexible substrate 106 disposed between the first metallization 102 and the second metallization 104, and a center conductor 108 embedded in the flexible substrate 106.

In embodiments, the center conductor 108 may be arranged asymmetrically with respect to the first metallization 102 and the second metallization 104. Thus, a first distance between the center conductor 108 and the first metallization 102 may be smaller than a second distance between the center conductor 108 and the second metallization 104.

As in 2 As further indicated, in embodiments, the flexible substrate 106 may include a first film 112_1 and a second film 112_2, with the center conductor 108 disposed between the first film 112_1 and the second film 112_2. The first film 112_1 and the second film 112_2 may be, for example, polyimide films.

As in 2 As can also be seen, in embodiments, the waveguide 100 can have a plurality of vias 114. The plurality of vias 114 can be arranged between the first metallization 102 and the second metallization 104, or the first metallization 102 and the second metallization 104 can be connected to one another (e.g., electrically) via the plurality of vias 114.

In embodiments, the plurality of vias 114 may be arranged to shield the center conductor 108. For example, the plurality of vias may be arranged on both sides (i.e., on opposite sides of the center conductor 108) along the center conductor 108, e.g., in the form of two via fences.

In embodiments, the flexible waveguide 100 may also have further center conductors, which may be arranged in the same substrate 106 between the first and second metallization 102, 104, for example, to the right and/or left with respect to the 2 shown plurality of vias 114, or in other words, so that the center conductors are separated from each other by so-called via fences that run between the first and second metallizations 102, 104. In this case, the plurality of vias can serve to reduce crosstalk between the different center conductors. Of course, the flexible waveguide 100 can also have further center conductors that are arranged in other substrates, e.g., with respect to 2 above the second metallization 104 and/or below the first metallization 102.

In other words, 2 shows a cross-section of an exemplary flexible waveguide (e.g., flexible cable). In the flexible waveguide (e.g., flexible cable) shown, the center conductor 108 can, in particular, be arranged such that the center conductor 108 is arranged closer to the lower shielding metallization 102 than to the upper shielding metallization 104 (so-called "asymmetric structure"). In the asymmetric structure, the layer thicknesses of the dielectrics 112_1 and 112_2 are consequently selected differently. This, on the one hand, achieves the technical advantage that a layer change or connector transition can be carried out more easily. The structure of the flexible waveguide could, for example, have the following layer thicknesses: film 2 with 50 µm, film 1 with 25 µm, and a metallization thickness of 0.5 µm. The asymmetric structure achieves the technical advantage that the adaptation of the characteristic impedance at the transition to a connector can be improved.

3a shows a schematic sectional view through a flexible waveguide 100 transverse to the wave propagation direction, wherein the waveguide 100 has a center conductor 108 with two striplines 110_1, 110_2 as superconductors and normal conductors, according to one embodiment. In other words, 3a shows a cross-section of a flexible waveguide (e.g. flexible cable) with superconducting and normal conducting materials.

As already mentioned in relation to the 1a and 1b As described, the center conductor 108 may comprise two striplines 110_1, 110_2. A first stripline 110_1 of the at least two striplines 110_1, 110_2 may comprise a superconducting material, while a second stripline 110_2 of the at least two striplines 110_1, 110_2 may comprise a non-superconducting material.

As in 3a As shown by way of example, the first stripline 110_1 and the second stripline 110_2 can be arranged one above the other with respect to the first and/or second metallization 102, 104, for example such that the first stripline and the second stripline 110_2 intersect a straight line 152 at different points that is perpendicular to the first and/or second metallization 102, 104. Alternatively, the first stripline 110_1 and the second stripline 110_2 can also be arranged next to one another with respect to the first and/or second metallization 102, 104, for example such that the first stripline and the second stripline 110_2 intersect a straight line 154 at different points that runs parallel to the first and/or second metallization 102, 104.

3b shows a schematic sectional view through a flexible waveguide 100 transverse to the wave propagation direction, wherein the waveguide 100 has a center conductor 108 with three striplines 110_1, 110_2, 110_3 as superconductors and normal conductors, according to an embodiment. In other words, 3b shows a cross-section of a flexible waveguide (e.g. flexible cable) with superconducting and normal conducting materials - three-part center conductor.

Compared to the 3a shown embodiment, the in 3b The center conductor 108 shown comprises three striplines 110_1-110_3. A first stripline 110_1 and a third stripline 110_3 can each comprise a superconducting material (e.g., the same superconducting material or different superconducting materials), while a second stripline 110_2 can comprise a non-superconducting material. Of course, in embodiments, the first stripline 110_1 and the third stripline 110_3 can each comprise non-superconducting materials, while the second stripline 110_2 comprises a superconducting material.

As this is the case in the 3a and 3b As indicated, in embodiments, the other metallizations, ie first metallization 102, second metallization 104 and/or the plurality of vias 114, may also have multiple layers, wherein a first layer comprises a superconducting material and a second layer comprises a non-superconducting material.

For example, the first metallization 102 may include a first layer 102_1 of superconducting material and a second layer 102_2 of non-superconducting material. The second metallization 104 may include a first layer 104_1 of non-superconducting material and a second layer 104_2 of superconducting material. The vias may include a first layer 114_1 of superconducting material and a second layer 114_2 of non-superconducting material.

In other words, 3a and 3b show the cross-section of further exemplary flexible waveguides (e.g., flexible cables). The flexible waveguides (e.g., flexible cables) shown are characterized by the fact that the metallization of the center conductor and/or the shielding was implemented using a material combination of at least one superconducting material (e.g., niobium below the critical temperature) and one non-superconducting material (e.g., copper). Optionally, an adhesion layer (e.g., titanium-tungsten) can be used as part of the material combination to bond the superconducting material and the non-superconducting material together. The adhesion layer can be incorporated into the material combination during manufacturing.

If the substrate is coated only with copper, for example, superconductivity cannot be achieved, but the waveguide (e.g., the cable) can also be used at higher temperatures (e.g., above the transition temperature of superconducting materials). The high shielding attenuation and decoupling described above are retained in this case as well. If, on the other hand, the substrate is coated with aluminum, it can function both as a superconductor at cryogenic temperatures and as a normal conductor at higher temperatures.

By combining several conductor materials from normal conductor and superconductor (e.g. copper and niobium, copper and aluminum) a particularly low-attenuation waveguide from cryogenic temperature range, from room temperature to high temperature (e.g. three-digit degrees Celsius) can be realized particularly easily. 3a and 3b The normal conductor is designated by reference numerals 110_2, 102_2, 104_1, and 114_2, and the superconductors by reference numerals 110_1, 110_3, 102_1, 104_2, and 114_1. This combination is also possible in reverse. Furthermore, a three-part inner conductor is also possible in the combination normal conductor-superconductor-normal conductor or superconductor-normal conductor-superconductor (see 3b) The magnitude of the simulated S21 parameters (insertion loss) in decibels for one millimeter of cable length is 4a to recognize.

In detail, 4a A diagram showing the simulated insertion loss in dB of a flexible waveguide with a superconductor and a normal conductor plotted against the frequency in GHz. A first curve 50 describes the insertion loss of the superconductor and the normal conductor at room temperature, while a second curve 52 shows the insertion loss of the superconductor and the normal conductor at cryogenic temperatures. In other words, 4a shows in a diagram simulated S21 parameters of superconductors and normal conductors at room temperature (50) and cryogenic temperatures (52).

This shows that the waveguide (e.g., the cable) can be used at both cryogenic and higher temperatures. For comparison, a purely niobium-based flexible waveguide (e.g., flexible cable) is 4b shown.

In detail, 4b A diagram showing the simulated insertion loss in dB of a niobium waveguide plotted against frequency in GHz. A first curve 60 describes the insertion loss of the niobium waveguide at room temperature, while a second curve 62 shows the insertion loss of the niobium waveguide at cryogenic temperatures. In other words, 4b shows in a diagram simulated S21 parameters of a niobium waveguide (e.g. niobium cable) at room temperature (60) and cryogenic temperatures (62).

5 shows a schematic sectional view through a flexible waveguide 100 transverse to the wave propagation direction, wherein the flexible waveguide 100 has two center conductors 108 embedded in different substrates, according to one embodiment. In other words, 5 shows an example of an n*3-layer flexible waveguide (e.g., flexible cable) with correspondingly more channels. The first center conductor 108_1 is embedded in a first substrate 106, which is arranged between the first metallization 102 and the second metallization 104, while the second center conductor 108_2 is embedded in a second substrate 106_2, which is arranged between the second metallization 104 and a third metallization 116.

As in 5 As indicated, in embodiments, the plurality of vias may connect the first metallization 102, the second metallization 104 and the third metallization 116 (e.g., electrically).

In other words, 5 shows the cross-section of another example of a flexible waveguide (e.g., a flexible cable). The waveguide (e.g., cable) shown uses more than three metal layers. The structure could, for example, correspond to the sequence of shielding - center conductor - shielding - center conductor - shielding - (...). Such an arrangement allows multiple layers to be realized, which can further increase the integration density of the flexible waveguide (e.g., a flexible cable).

6a shows a schematic sectional view through a flexible waveguide 100 transverse to the wave propagation direction, wherein the flexible waveguide 100 has two center conductors 108 arranged next to one another, according to an embodiment.

6b shows a schematic sectional view through a flexible waveguide 100 transverse to the wave propagation direction, wherein the flexible waveguide 100 has two center conductors 108 arranged one above the other, according to an embodiment.

As already described above in the other embodiments, the 6a and 6b The waveguide 100 shown comprises a first metallization 102, a second metallization 104, a flexible substrate 106 arranged between the first metallization 102 and the second metallization 104, and a plurality of vias 114 extending between the first metallization 102 and the second metallization 104 and connecting them (e.g. electrically).

Compared to the embodiments described above, the 6a and 6b The flexible waveguide 100 shown has not only one center conductor, but two center conductors 108_1 and 108_2.

In the 6a In the embodiment shown, the two center conductors 108_1 and 108_2 are arranged next to one another, e.g. such that the first center conductor 108_1 and the second center conductor 108_2 intersect a straight line 156 at different points, which runs parallel to the first and/or second metallization 102, 104.

In the 6b In the embodiment shown, the two center conductors 108_1 and 108_2 are arranged one above the other, so that the first center conductor 108_1 and the second center conductor 108_2 intersect a straight line 158 at different points, which is perpendicular to the first and/or second metallization 102, 104.

In other words, 6a and 6b show cross-sections of other exemplary flexible waveguides (e.g., flexible cables). The flexible waveguides (e.g., flexible cables) shown use different arrangements with center conductors (directly) stacked or (directly) adjacent to each other for carrying (e.g., differential) signals. For example, this can achieve higher common-mode rejection and thus better signal integrity.

The 5 , 6a and 6b The center conductors shown can of course each have at least two striplines, wherein at least one of the at least two striplines has superconducting material.

In other embodiments, the center conductors can also each have different structures. For example, only one center conductor can have at least two striplines, with at least one of the at least two striplines comprising superconducting material, while the other center conductor can have only one stripline made of a superconducting material or a non-superconducting material.

In further embodiments, the flexible waveguide comprises a plurality of center conductors, for example, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, or 500 center conductors, which are embedded in the same substrate or which are embedded in different substrates. Depending on the application, within such a flexible waveguide, only individual center conductors, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 center conductors, can each have at least two striplines, wherein at least one of the at least two striplines comprises superconducting material.

In embodiments, the other metallizations (e.g., first metallization, second metallization, and/or the plurality of vias) may each comprise two layers, wherein at least one of the two layers comprises superconducting material.

7 shows a schematic sectional view through a flexible waveguide 100 transverse to the wave propagation direction, wherein the flexible waveguide 100 has two center conductors 108 arranged one above the other, which are connected to each other via vias 118, according to an embodiment. In other words, 7 shows a cross-section of a flexible waveguide (e.g. a flexible cable) with two center conductors, the two center conductors being connected to each other by means of a via.

As already described above, the 7 The waveguide 100 shown comprises a first metallization 102, a second metallization 104, a flexible substrate 106 arranged between the first metallization 102 and the second metallization 104, and a plurality of vias 114 extending between the first metallization 102 and the second metallization 104 and connecting them (e.g., electrically). Furthermore, the waveguide 100 comprises two center conductors 108_1 and 108_2 embedded in the substrate 106 and arranged one above the other, which are connected to one another via vias 118.

In other words, 7 A cross-section of another example of a flexible waveguide (e.g., a flexible cable). In the flexible waveguide (e.g., a flexible cable) shown, two center conductors are connected by means of a through-hole plating (i.e., a via) to form a conductor with a larger cross-section. This allows for higher current-carrying capacity and better heat dissipation.

8 shows a schematic sectional view transverse to the wave propagation direction of a center conductor 108 with three striplines 110_1-110_3, wherein a first stripline 110_1 is embedded between a second stripline 110_2 and a third stripline 110_3, according to an embodiment. As in 8 As can be seen, the first stripline 110_1 can be arranged on the second stripline 110_2, wherein the third stripline 110_3 can be arranged on the first stripline 110_1 and the second stripline 110_2, so that the third stripline 110_3 and the second stripline 110_3 embed the first stripline 110_1.

The center conductor 108 is in 8 arranged on a first foil 112_1 of a flexible substrate. A second foil could be arranged on the center conductor 108 and the first foil 112_2 to embed the center conductor 108 in the first foil 112_1 and the second foil. The two foils could then again form a flexible substrate, wherein the substrate can be arranged between two metallizations to form a flexible waveguide, as already described in detail above.

All features of the embodiments disclosed herein described or shown can be combined with one another in any way to simultaneously realize their technical advantages. For example, the asymmetric structure can be combined with the material combination of superconducting material and non-superconducting material. Furthermore, a single-ended signal or a differential signal can generally be transmitted via the flexible waveguide (e.g., flexible cable).

In addition, multiple layers can be arranged one above the other, with each layer having an identical structure. Alternatively, the individual layers can have different structures depending on the application.

2. Manufacturing process for a flexible waveguide

An embodiment of a method for producing a flexible waveguide is described below.

9 shows a flowchart of a method 200 for manufacturing a flexible waveguide, according to an embodiment. The method 200 comprises a step 202 of providing a first layer of a flexible substrate. The method 200 further comprises a step 204 of providing a center conductor on the first layer of the flexible substrate, wherein the center conductor comprises at least two striplines, and wherein at least one stripline of the at least two striplines comprises a superconducting material. The method 200 further comprises a step 206 of providing a second layer of the flexible substrate on the first layer of the flexible substrate and the center conductor, such that the center conductor is embedded between the first layer of the flexible substrate and the second layer of the flexible substrate. Furthermore, the method 200 comprises a step 208 of providing a first metallization and a second metallization, wherein the first metallization is provided on a first side of a stack of the first layer of the flexible substrate and the second layer of the flexible substrate, and wherein the second metallization is provided on a second side of the stack opposite the first side.

In the following, a further embodiment of a method for producing a flexible waveguide is described. Such a method enables, for example, the automated and reproducible production of flexible waveguides (e.g., flexible cables). The production and automated production of flexible three-layer waveguides can, for example, be carried out consecutively in several process steps, for example, in an automated roll-to-roll process, as described in the 10a -g is shown.

Show in detail 10a -g schematic sectional views of the flexible waveguide after different steps during its manufacture. In other words, 10a -g show process steps for producing flexible waveguides.

In detail, 10a a schematic sectional view of the flexible waveguide during its manufacture after a step of providing a first layer of a flexible substrate of the flexible waveguide and a step of forming at least one hole 120 through the first layer of the flexible substrate.

In exemplary embodiments, vias and alignment marks can first be laser-drilled through the entire thickness of a flexible substrate film, for example, made of polyimide (PI) (e.g., with a thickness of 25 µm). The vias can later serve as signal vias for electrical contact between the front and back of the substrate film. The alignment marks serve to align the metallization with the vias during lithographic patterning.

10b shows a schematic sectional view of the flexible waveguide during its manufacture after a step of coating (e.g. by sputtering, thermal vapor deposition, or electroplating) the first layer 112_1 of the flexible substrate with a first metallization 102, wherein during the double-sided coating, side walls of the at least one hole 120 are coated with the first metallization in order to obtain at least one via.

In embodiments, in step of 10b a metal layer on both sides and in the borehole walls of the foil from the step of 10a e.g., by sputtering. It may be necessary to activate the surface of the substrate film beforehand (within the sputtering tool, without interrupting the vacuum). This ensures the required adhesion of the metal to the film. Another way to improve the adhesion between a metal layer, such as niobium, and a PI film is by depositing TiW, for example, as an intermediate layer. To produce superconducting structures, metallizations (e.g., niobium) can be applied that become superconducting below a critical temperature.

During this process step, it is also possible to deposit different metals in order to integrate different functions in a very small space depending on the requirements.

For example, signal cables could be made partly of niobium and partly of copper in order to optimize heat conduction in the cable.

10c shows a schematic sectional view of the flexible waveguide during its manufacture after a step of structuring (e.g. by a combination of photolithography and etching (e.g. wet chemical and/or plasma-assisted) of the first metallization 102 in order to obtain a center conductor of the flexible waveguide on a first side of the first layer of the flexible substrate and to obtain a connection surface for electrically contacting the center conductor on a second side of the first layer of the flexible substrate facing away from the first side, wherein the connection surface and the center conductor are connected to one another via the at least one via (e.g. electrically).

In exemplary embodiments, the pre-processed film can be laminated on both sides with a photoresist. The structure of the signal lines and the contact pads of the flexible waveguide to be manufactured are defined on the front and back, for example, by (double-sided) UV exposure. The exposed area of the photoresist crosslinks (negative tone resist) and becomes insoluble. The unexposed part is dissolved in a solution, e.g., sodium carbonate (Na2CO3), and washed off. The structuring of the metallization on the front and back of the film is achieved by etching. This can be done either by plasma or wet etching. The photoresist is then stripped off in a solution, e.g., potassium hydroxide (KOH).

10d shows a schematic sectional view of the flexible waveguide during its manufacture after a step of providing a second layer 112_2 of the flexible substrate on the first side of the first layer of the flexible substrate.

In embodiments, the metallized film can now be laminated with a second dielectric layer, with or without an (acrylic) adhesive between the two film layers.

10e shows a schematic sectional view of the flexible waveguide during its manufacture after a step of forming a plurality of holes through the first layer 112_1 and the second layer 112_2 of the flexible substrate.

In some embodiments, additional vias and new alignment marks can be laser-drilled through the laminated foil. These vias later serve to establish electrical contact between the front and back sides of the waveguide's outer shield layer. The laser-applied alignment marks are used to position the metallization.

10f shows a schematic sectional view of the flexible waveguide during its manufacture after a step of coating the flexible substrate on both sides with a second metallization 124, wherein during the double-sided coating, side walls of the plurality of holes are coated with the second metallization to obtain a plurality of vias.

In exemplary embodiments, an additional metal layer is deposited on the outer surfaces of the pre-processed substrate and the previously created bore walls as a shield, for example, using sputtering. This electrically connects the front and back sides of the shielding layer via vias. Niobium and/or copper, for example, can be used as the shielding metallization, so that no heat is generated due to conduction losses in the superconducting state. The additionally applied copper could serve to dissipate passive heat caused by temperature differences in the cryostat.

10g shows a schematic sectional view of the flexible waveguide during its manufacture after a step of structuring the second metallization 124 to obtain a first shielding metallization of the flexible waveguide.

In some embodiments, a photoresist can be applied to the layer composite and exposed to pattern the shield layer metallization. Niobium can be patterned, for example, by plasma etching. When using other metallizations, such as Cu, wet etching can be performed using, for example, sodium persulfate solution (Na2S2O8). Both etching steps can be performed with the same photoresist layer.

Through the structuring in the 10g Finally, the steps shown in the step from 10c The contact surfaces generated are electrically separated from the surrounding shielding layers. This results, for example, in a contact surface according to 11 .

3. Connection surfaces of the flexible waveguide

11 shows a schematic view of connection pads 130_1-130_3 of the flexible waveguide 100, according to an embodiment. In other words, 11 shows an exemplary contact surface of a flexible waveguide 100.

As in 11 As can be seen, the connection pads 130_1-130_3 can be exposed in a plane of the first metallization 102 (or alternatively the second metallization), i.e., electrically insulated from the first metallization 102. The connection pads 130_1-130_3 can be connected to respective center conductors of the flexible waveguide 100 via respective vias 132_1-132_3.

In embodiments, the flexible waveguide 100 may include a plurality of vias 134, wherein the plurality of vias 134 are arranged such that the plurality of vias 134 surround the first pad 130_1 (and the first center conductor), surround the second pad 130_2 (and the second center conductor), and surround the third pad 130_3 (and the third center conductor), and shield the first pad 130_1, the second pad 130_2, and the third pad 130_3 from each other. This may reduce crosstalk between the different pads and the respective center conductors.

In embodiments, the three connection surfaces 130_1-130_3 may have different distances from an end 134 of the flexible waveguide.

4. Applications of the flexible waveguide

Flexible waveguide designs are used when signals need to be transmitted in a very small space while simultaneously achieving optimized heat conduction. The latter is made possible, in particular, by a combination of materials and the described layer structure.

4.1 Quantum computing with superconducting qubits

One conceivable application of the flexible waveguide (e.g., interconnect system) is signal transmission in a quantum computer. Examples of flexible waveguides can be used to replace coaxial cables. This can significantly increase the signal density in the cryostat. By using superconducting materials (e.g., niobium) for the signal lines and shielding layers of the flexible waveguide, heat losses can be reduced. At the same time, additional metal layers can be added to optimize heat conduction so that only a small amount of passive heat is transferred from one temperature level in the cryostat to the next. This allows the number of lines in the cryostat to be increased. Thus, the flexible waveguide can ensure the signal and power supply in the cryostat even as the number of qubits in the quantum computer increases.

12 shows a schematic block diagram of a quantum computer 300 according to an embodiment. In other words, 12 shows an installation of flexible waveguides in the cryostat. The quantum computer 300 comprises a quantum processor (Quantum Processing Unit, QPU) 302, a signal generator and/or signal evaluator 304, a cryostat for generating different temperature levels (e.g., room temperature, 300 K, 4 K, 1.5 K, 100 mK, 20 mK), and at least one flexible waveguide 100 for signal routing between the quantum processor 304 and the signal generator and/or signal evaluator 304.

As in 12 As can be seen, the at least one flexible waveguide 100 can be used across all temperature levels (e.g. room temperature, 300 K, 4 K, 1.5 K, 100 mK, 20 mK), ie continuously from a temperature level (e.g. room temperature) of the signal generator and/or signal evaluator 304 to a temperature level of the quantum processor, e.g. via feedthroughs in the temperature levels (or temperature levels) of the cryostat.

Examples of implementation allow lines to be led directly from the 4K stage into the so-called mixing chamber (MXC), since the heat transfer is reduced (or even minimized) by the material combination and thus the desired temperature of a few mK can be achieved despite passive heat conduction.

The shielding concept also ensures low crosstalk between the cables and thus high signal integrity. Manufacturing can be carried out using the process described above.

4.2 Phased array antennas

Embodiments of the flexible waveguide can be used to connect remote phased array antennas, e.g., in radar and communications applications. Superconducting materials are typically not used in such cases, as these are not cryogenic applications. Good conductors, such as copper or silver, are more suitable here. This allows for a more compact antenna with few or no active components. Active signal processing takes place in a central unit.

This could be the case, for example, in a satellite. The highly integrated cable connects an antenna array mounted on the outside of the satellite to a central unit that transmits and receives the data and processes it accordingly. This has the advantage that most of the waste heat from the transmitting and receiving system is generated elsewhere. This may simplify cooling. Hybrid solutions are also conceivable here, in which some electronic components such as phase shifters or amplifiers are integrated into the antennas, while the connection to the transmitting and receiving unit is established via numerous highly integrated waveguides.

13 shows a schematic block diagram of a satellite 320 with a flexible waveguide 100, according to one embodiment. The satellite 320 includes an external antenna 322, such as an antenna array, and a transmitting and/or receiving device 324, wherein the flexible waveguide 100 is used for signal transmission between the at least one external antenna 322 and the transmitting and/or receiving device 324.

Remote antennas connected by highly integrated cables are also possible for radar devices with electronically controlled group antennas.

4.3 Sensor signal connection for automotive applications

Examples of the flexible cable can be used as part of the automotive electrical system. Due to the potentially high signal density, electronic components in the vehicle can be connected to both They can be supplied with both power and signals. One possible application is the transmission of sensor data to a control unit.

Another advantage is that the flexible waveguide can be adapted to the vehicle's contours, ensuring optimal use of the installation space. This is particularly important given the increasing functional density of modern vehicles.

5. Further examples

Although some aspects have been described in connection with a device, it should be understood that these aspects also represent a description of the corresponding method, so that a block or component of a device can also be understood as a corresponding method step or as a feature of a method step. Analogously, aspects described in connection with or as a method step also represent a description of a corresponding block, detail, or feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware apparatus, such as a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, some or more of the key method steps may be performed by such an apparatus.

The above-described embodiments are merely illustrative of the principles of the present invention. It is understood that modifications and variations of the arrangements and details described herein will be apparent to others skilled in the art. Therefore, it is intended that the invention be limited only by the scope of the following claims and not by the specific details presented in the description and explanation of the embodiments herein.

Bibliography

1. [1] Krinner, S., Storz, S., Kurpiers, P. et al. “Engineering cryogenic setups for 100-qubit scale superconducting circuit systems” - EPJ Quantum Technology 6(1)
2. [2] David B Tuckerman, Michael C Hamilton, David J Reilly, Rujun Bai, George A Hernandez, John M Hornibrook, John A Sellers, Charles D Ellis, “Flexible superconducting Nb transmission lines on thin film polyimide for quantum computing applications”, Superconductor Science and Technology 29 (2016) 084007 (12pp), DOI:10.1088/0953-2048/29/8/084007 .
3. [3] Shuna Wang, Wenbing Jiang, Huiqin Yu et al. “Functional flexible cables for cryogenic quantum systems” - 2022 IEEE 15th Workshop on Low Temperature Electronics (WOLTE )
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QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• Krinner, S., Storz, S., Kurpiers, P. et al. “Engineering cryogenic setups for 100-qubit scale superconducting circuit systems” - EPJ Quantum Technology 6(1) [0159]
• David B Tuckerman, Michael C Hamilton, David J Reilly, Rujun Bai, George A Hernandez, John M Hornibrook, John A Sellers, Charles D Ellis, “Flexible superconducting Nb transmission lines on thin film polyimide for quantum computing applications”, Superconductor Science and Technology 29 (2016) 084007 (12pp), DOI:10.1088/0953-2048/29/8/084007 [0159]
• Shuna Wang, Wenbing Jiang, Huiqin Yu et al. “Functional flexible cables for cryogenic quantum systems” - 2022 IEEE 15th Workshop on Low Temperature Electronics (WOLTE [0159]
• List of transition temperatures of chemical elements." In: Wikipedia - The Free Encyclopedia. Edited on: July 4, 2022, 10:16 UTC. URL: https://de.wikipedia.org/w/index.php?title=Liste_der_Sprungtemperaturen_che mischer_Elemente&oldid=224223235 (Accessed: September 22, 2023, 12:39 UTC [0159]

Claims (27)

A flexible waveguide (100), comprising: a first metallization (102), a second metallization (104), a flexible substrate (106) disposed between the first metallization (102) and the second metallization (104), and a center conductor (108) embedded in the flexible substrate (106), wherein the center conductor (108) comprises at least two striplines (110_1, 110_2), wherein at least one stripline of the at least two striplines (110_1, 110_2) comprises a superconducting material. Flexible waveguide (100) according to Claim 1 , wherein a first stripline (110_1) of the at least two striplines (110_1, 110_2) comprises a first superconducting material, and wherein a second stripline (110_2) of the at least two striplines (110_1, 110_2) comprises a second superconducting material. Flexible waveguide (100) according to Claim 2 , where the first superconducting material and the second superconducting material are two different materials. Flexible waveguide (100) according to Claim 1 , wherein a first stripline (110_1) of the at least two striplines (110_1, 110_2) comprises a superconducting material, and wherein a second stripline (110_2) of the at least two striplines (110_1, 110_2) comprises a non-superconducting material. Flexible waveguide (100) according to one of the preceding claims, wherein the non-superconducting material does not exhibit superconducting properties at any temperature, and/or wherein the superconducting material exhibits superconducting properties at temperatures below a material-specific transition temperature. A flexible waveguide (100) according to any one of the preceding claims, wherein the superconducting material is one of the following materials: niobium, aluminum, lead, indium, zinc, tantalum or niobium nitride. A flexible waveguide (100) according to any one of the preceding claims, wherein the non-superconducting material is one of the following materials: copper, nickel, gold or silver. Flexible waveguide (100) according to one of the preceding claims, wherein the at least two striplines (110_1, 110_2) run parallel to each other. Flexible waveguide (100) according to one of the preceding claims, wherein the at least two striplines (110_1, 110_2) are connected to each other. Flexible waveguide (100) according to the preceding claim, wherein the at least two striplines (110_1, 110_2) are directly connected to one another, or wherein the at least two striplines (110_1, 110_2) are connected to one another by means of an adhesion layer. The flexible waveguide (100) according to any one of the preceding claims, wherein a third stripline (110_3) of the at least two striplines (110_1, 110_2) comprises a superconducting material, the second stripline (110_2) being arranged between the first stripline (110_1) and the third stripline (110_3), or wherein a third stripline (110_3) of the at least two striplines (110_1, 110_2) comprises a non-superconducting material, the first stripline (110_1) being arranged between the second stripline (110_2) and the third stripline (110_3). Flexible waveguide (100) according to Claim 11 , wherein the second stripline (110_2) is embedded between the first stripline (110_1) and the third stripline (110_3), or wherein the first stripline (110_1) is embedded between the second stripline (110_2) and the third stripline (110_3). Flexible waveguide (100) according to one of the preceding claims, wherein the first metallization (102) and/or the second metallization (104) each comprise at least two metallization layers (102_1, 102_2, 104_1, 104_2), wherein at least one metallization layer (102_1, 104_2) of the at least two metallization layers (102_1, 102_2, 104_1, 104_2) comprises a superconducting material. Flexible waveguide (100) according to Claim 13 , wherein a first metallization layer (102_1, 104_2) of the at least two metallization layers (102_1, 102_2, 104_1, 104_2) comprises a first superconducting material, and wherein a second metallization layer (102_2, 104_1) of the at least two metallization layers (102_1, 102_2, 104_1, 104_2) comprises a second superconducting material Flexible waveguide (100) according to Claim 13 , wherein a first metallization layer (102_1, 104_2) of the at least two metallization layers (102_1, 102_2, 104_1, 104_2) comprises a superconducting material, and wherein a second metallization layer (102_2, 104_1) of the at least two metallization layers (102_1, 102_2, 104_1, 104_2) comprises a non-superconducting material. A flexible waveguide (100) according to any one of the preceding claims, wherein the flexible substrate (106) comprises polyimide. Flexible waveguide (100) according to one of the preceding claims, wherein a first distance between the center conductor (108) and the first metallization (102) is less than or greater than a second distance between the center conductor (108) and the second metallization (104). Flexible waveguide (100) according to one of the preceding claims, wherein the first metallization (102) and the second metallization (104) are connected to one another via a plurality of vias (114). The flexible waveguide (100) according to the preceding claim, wherein the plurality of vias (114) each comprise two via layers (114_1, 114_2), wherein a first via layer (114_1) of the two via layers (114_1, 114_2) comprises a superconducting material, and wherein a second via layer (114_2) of the two via layers (114_1, 114_2) comprises a non-superconducting material. The flexible waveguide (100) according to any one of the preceding claims, wherein the center conductor (108) is a first center conductor (108_1), wherein the flexible waveguide (100) has a second center conductor (108_2) arranged at a distance from the first center conductor (108_1). Flexible waveguide (100) according to Claim 20 , wherein the second center conductor (108_2) is embedded in the flexible substrate (106). Flexible waveguide (100) according to Claim 21 , wherein the first center conductor (108_1) and the second center conductor (108_2) are arranged next to one another in the substrate (106) with respect to the first metallization (102) and/or second metallization (104). Flexible waveguide (100) according to Claim 21 , wherein the first center conductor (108_1) and the second center conductor (108_2) are arranged one above the other in the substrate (106) with respect to the first metallization (102) and/or second metallization (104). Flexible waveguide (100) according to Claim 22 or 23 , wherein the first center conductor (108_1) and the second center conductor (108_2) are connected to one another via at least one via (118). Flexible waveguide (100) according to Claim 20 , wherein the substrate (106) is a first substrate (106_1), wherein the flexible waveguide (100) comprises a second substrate (106_2) and a third metallization (116), wherein the second substrate (106_2) is arranged between the second metallization (104) and the third metallization (116), wherein the second center conductor (108_2) is embedded in the second substrate (106_2). Quantum computer (300), having the following features: a quantum processor (302), a signal generator and/or signal evaluator (304), and at least one flexible waveguide (100) according to one of the Claims 1 until 25 for signal transmission between the quantum processor (302) and the signal generator and/or signal evaluator (304). Quantum computers according to Claim 26 , wherein the quantum processor (320) is designed to operate at a cryogenic temperature, and/or wherein the signal generator and/or signal evaluator (304) is designed to operate at a cryogenic temperature or a non-cryogenic temperature.

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