CN108011164A - Substrate integrates artificial surface phasmon waveguide - Google Patents

Abstract

The substrate integrated artificial surface plasmon waveguide relates to the plasmon waveguide. There are substrate integrated waveguides and metal slots, the metal slots are set on the substrate integrated waveguide, the metal slots are periodic metal slots, and the metal slots are distributed on one side of the substrate integrated waveguide or symmetrically , antisymmetric, offset symmetric, etc. are distributed on both sides of the substrate integrated waveguide, and are used to transmit microwave and terahertz artificial surface plasmons with strong local field confinement performance. It has band-pass characteristics and has relatively steep rising and falling edges, and the pass-band range can be adjusted by changing the effective length of the slot and the width of the substrate integrated waveguide. Through scale transformation, the size of the unit and the branch structure is enlarged and reduced, and it can be used for the transmission of artificial surface plasmon electromagnetic waves in the microwave, millimeter wave or terahertz bands.

Description

Substrate-integrated artificial surface plasmon waveguide

technical field

The invention relates to a plasmon waveguide, in particular to a substrate-integrated artificial surface plasmon waveguide.

Background technique

With the development of information technology, the capacity requirements of communication systems are getting higher and higher. At the same time, due to the extremely rich spectrum resources in high-frequency microwave frequency bands, modern communication systems are developing towards high-frequency microwaves, especially millimeter-wave frequency bands. Microstrip circuits have the advantages of small size, compact structure, light weight, and low cost, and are widely used in microwave circuits. However, at higher frequencies, especially in the millimeter wave frequency band, the electromagnetic wave leakage and radiation of the microstrip circuit are relatively serious, and the transmission loss of the circuit is large. Although the metal waveguide has the advantages of low insertion loss, low radiation, and high quality factor in the high-frequency band, its volume is too large, processing is difficult, and the cost is expensive. In 2002, Wu Ke and others published the paper "Integrated microstrip and rectangular waveguide in planar form" in IEEE Microwave & Wireless Components Letters, and proposed a new planar waveguide - the concept of Substrate Integrated Waveguide (SIW). The structure is composed of upper and lower layers of metal, a medium filled in the middle, and two rows of metal through holes on the left and right. It is a transmission line between the microstrip and the dielectric filled waveguide. SIW can realize high-performance microwave and millimeter-wave planar circuits. The two rows of metal vias are equivalent to the metal walls of the rectangular waveguide. The electromagnetic waves are bound in the closed space formed by the upper and lower metal surfaces and the metal columns on both sides. The main mode in which the electromagnetic wave propagates is the TE10 mode, and its field distribution is very similar to that of a rectangular waveguide. The substrate-integrated waveguide is equivalent to a planarized rectangular waveguide, and its flexibility and integrability have been greatly improved in comparison. At the same time, the planar nature of the substrate-integrated waveguide enables it to transition with planar transmission lines such as microstrip lines or striplines, which is beneficial to the miniaturization and integration of equipment. In order to achieve the strong confinement properties of surface plasmons in the optical or infrared bands in lower frequency bands such as microwave and terahertz, the concept of artificial surface plasmon polaritons (Spoof Surface Plasmon Polaritons, SSPPs) was proposed. . In 2013, Xiaopeng Shen, Tie Jun Cui et al. published the paper "Planar plasmonic metamaterial on a thin film with nearly zero thickness" in Applied Physics Letters, which researched that a periodically slotted ultra-thin metal film transmission line can guide artificial surface plasmons The element realizes the transformation of the artificial surface plasmon waveguide from a three-dimensional structure to a planar structure. Artificial surface plasmon waveguides with planar structures have important applications in the miniaturization of microwave and terahertz integrated circuits and systems, so it is very important to study artificial surface plasmon waveguides with flat and high transmission efficiency. practical significance.

Contents of the invention

The purpose of the present invention is to provide a substrate-integrated artificial surface plasmon waveguide in order to realize an artificial surface plasmon waveguide with excellent transmission characteristics and strong binding performance in the microwave and terahertz bands.

The present invention is provided with a substrate integrated waveguide and metal slots, the metal slots are arranged on the substrate integrated waveguide, the metal slots are periodic metal slots, and the metal slots are distributed on one side of the substrate integrated waveguide or They are distributed on both sides of the substrate integrated waveguide in the form of symmetry, antisymmetry, offset symmetry, etc., and are used to transmit microwaves and terahertz artificial surface plasmons with strong local field confinement performance.

The shape of the metal slot can be rectangular, bent, T-shaped, L-shaped, spiral, etc. The structure itself has a band-pass characteristic, and has relatively steep rising and falling edges, and the pass-band range can be adjusted by changing the effective length of the slot and the width of the substrate-integrated waveguide.

The invention enlarges and reduces the unit and branch structure size through scale transformation, and can be used for the transmission of artificial surface plasmon electromagnetic waves in microwave, millimeter wave or terahertz wave bands.

The beneficial effects of the present invention are:

1) The present invention transmits surface plasmons through periodic grooves on the substrate integrated waveguide, the asymptotic frequency of its dispersion curve is low, the performance of binding electromagnetic fields is strong, and the phenomenon of electromagnetic wave radiation in the high frequency band is reduced at the same time.

2) The present invention can adopt a flexible substrate, which can be used for conformal transmission of microwaves and terahertz artificial surface plasmon electromagnetic waves through bending deformation.

3) The present invention has a band-pass characteristic, and has relatively steep rising and falling edges, and the pass-band range can be adjusted by controlling the effective length of the metal film slot and the width of the substrate integrated waveguide.

4) The transmission characteristics of the present invention mainly depend on the effective length of the metal slot and the width of the substrate integrated waveguide. The manual design is convenient and flexible. Through scale transformation, the size of the unit and the branch structure is enlarged and reduced, and it can be used for microwave and millimeter waves. , or the transmission of artificial surface plasmon electromagnetic waves in the terahertz band.

5) The present invention belongs to a flat structure. Since the substrate integrated waveguide is perfectly matched with the microstrip line, it can be used to design various microwave and millimeter wave or even terahertz filters, power splitters, couplers, antennas, amplifiers, and mixers. Such as passive and active circuits, devices and even components or systems.

Description of drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Fig. 2 is a dispersion curve diagram of an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a band-pass filter based on an embodiment of the present invention.

Fig. 4 is the S parameter of the bandpass filter based on the embodiment of the present invention.

Detailed ways

The following embodiments will further illustrate the present invention in conjunction with the accompanying drawings.

Example 1

It is a substrate-integrated artificial surface plasmon waveguide with double-sided rectangular slots, as shown in Figure 1, embodiment 1 is provided with a substrate-integrated waveguide 1 and a metal slot 2, and the metal slot 2 is set on the substrate The integrated waveguide 1, the metal slot 2 is a periodic metal slot, and the metal slot 2 is distributed on one side of the substrate integrated waveguide 1 or distributed on the substrate integrated waveguide 1 in a manner of symmetry, antisymmetry, offset symmetry, etc. Double-sided, used to transmit microwave and terahertz artificial surface plasmons with strong local field confinement properties, the material of the dielectric substrate is Rogers RT5880, the dielectric constant is 2.2, the thickness is 0.508mm, and the transmission loss angle is 0.0009; the material of the metal film transmission line and the metal via is selected as copper. The size of the unit structure of the waveguide is selected as a=12mm, d=2.5mm, and h increases from 5mm to 8mm. The dispersion curve obtained by simulation analysis is shown in Figure 2. All dispersion curves deviate from the light. With the increase of the slot height h, Gradual frequency decrease. Taking advantage of the high-pass characteristics of the substrate-integrated waveguide and the low-pass characteristic of the artificial surface plasmon waveguide, the lower and upper cut-off frequencies are determined by the width a of the substrate-integrated waveguide and the slot height h, respectively, and can be adjusted by adjusting a and h Size Design a bandpass filter to meet a specific bandwidth requirement.

Example 2

The band-pass filter designed for the application of Embodiment 1 is shown in FIG. 3 . The filter is divided into three parts, the left and right ends are microstrip transmission lines, and the middle is a substrate-integrated artificial surface waveguide with double-sided rectangular metal slots. The filter has a symmetrical structure, both ends are feed terminals, w ₀ =1.6mm, which ensures a port impedance of 50Ω. The tapered transition structure is used to convert the electromagnetic wave from the microstrip line to the substrate integrated waveguide, w _tra =3.5mm, and the impedance matching with the substrate integrated waveguide is realized. In order to achieve wave vector matching, the height of metal slots is distributed in a gradually increasing manner. Other main parameters are as follows: a=12mm, d=2.5mm, h=8mm. It can be seen from the simulation results in Fig. 4 that the bandpass range of the filter is from 8.5GHz to 12.3GHz, and it has relatively steep rising and falling edges.

The invention discloses a substrate-integrated artificial surface plasmon waveguide. The artificial surface plasmon waveguide is composed of a substrate-integrated waveguide and periodic metal slots thereon. The metal slots can be distributed on one side of the substrate-integrated waveguide or distributed on both sides of the substrate-integrated waveguide in the form of symmetry, anti-symmetry, offset symmetry, etc., and are used to transmit microwaves with strong local field confinement performance. Artificial Surface Plasmons with Terahertz. The shape of the metal groove is rectangular, and it can also be bent, T-shaped, L-shaped, spiral and other shapes. The structure of the invention has a band-pass characteristic, and the range of the pass-band can be adjusted by changing the effective length of the slot and the width of the substrate integrated waveguide. The invention adopts planar structure, small size and high transmission efficiency. It is a new artificial surface plasmon waveguide with great potential, and has important application prospects in microwave, millimeter wave and terahertz circuits, devices and systems.

Claims (2)

1. substrate integrates artificial surface phasmon waveguide, it is characterised in that described equipped with substrate integration wave-guide and slotted metal Slotted metal is located at substrate integration wave-guide, and slotted metal is periodicity slotted metal, and the slotted metal is distributed in substrate and integrates The single side of waveguide is distributed in the two-sided of substrate integration wave-guide in symmetrical, antisymmetry, offset symmetric mode, is used for transmission with pole The microwave and Terahertz artificial surface phasmon of Local field enhancement constraint performance.

2. substrate as claimed in claim 1 integrates artificial surface phasmon waveguide, it is characterised in that the shape of the slotted metal Shape is using rectangle, bending shape, T-shaped, L-shaped, spiral shape.