KR100974438B1 - Phase adjuster with metamaterial element - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase adjuster using a metamaterial phenomenon. In particular, a phase adjuster including a right left handed (RLH) cell using a metamaterial phenomenon is constructed, and the inductor and the capacitor are tunably adjusted using a trimmer process. It relates to a miniaturized phase adjuster.

The phase adjuster of the present invention comprises: an input impedance unit having a signal input to one end and having a resistance component and a negative capacitance component; A first transmission line, one end of which is connected to the other end of the input impedance unit and through which the signal passes; A second transmission line having one end connected to the other end of the first transmission line and through which the signal passes; An output impedance unit having one end connected to the other end of the second transmission line, the signal being output to the other end, and having a resistance component and a negative capacitance component; And a ground admittance unit having one end connected to the connection node of the first transmission line and the second transmission line, the other end connected to the ground, and having a resistance component and a negative inductance component.

Metamaterials, Phase Adjusters, Inductors, Capacitors, Trimming

Description

Phase adjuster containing metamaterial elements {PHASE SHIFTER COMPRISING METAMATERIAL ELEMENT}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase adjuster using a metamaterial phenomenon. In particular, a phase adjuster including a right left handed (RLH) cell using a metamaterial phenomenon is constructed, and the inductor and the capacitor are tunably adjusted using a trimmer process. It relates to a miniaturized phase adjuster.

Meta-material means a material or an electromagnetic structure that is artificially designed to have special electromagnetic properties not normally found in nature, and is generally referred to in the art and referred to herein as metamaterial. Means a material or such an electromagnetic structure that is both negative in permittivity and permeability.

Such materials are also called Double Negative (DGN) materials in the sense of having two negative parameters. In addition, metamaterials have a negative reflection coefficient due to negative permittivity and permeability, and are thus also called NRI (Negative Refractive Index) materials. Metamaterial was first studied by Soviet physicist V. Veselago in 1967, but more than 30 years later, a concrete implementation method has been studied and application has been attempted.

Due to these characteristics, electromagnetic waves in metamaterials are transmitted by the left-hand rule rather than following Fleming's right-hand rule. That is, the phase propagation direction (phase velocity direction) and the energy propagation direction (group velocity direction) of the electromagnetic waves are reversed, so that the signal passing through the metamaterial has a negative phase delay. do.

Accordingly, metamaterials are sometimes referred to as left-handed materials (LHMs). In addition, the relationship between β (phase constant) and ω (frequency) is not linear in the metamaterial, and the characteristic curve is also present in the left half of the coordinate plane. Due to such nonlinear characteristics, the metamaterial has a small phase difference according to frequency, so that a wideband circuit can be realized. Since the phase change is not proportional to the length of the transmission line, a small circuit can be realized.

When applied to the existing electronic circuit using the metamaterial phenomenon, it is possible to achieve a heterogeneous effect that was not previously expected. However, in the field of phase adjusters, a structure using metamaterial phenomenon, which has high practicality, has not been proposed yet.

The principle of metamaterial phenomena is described in 2006 IEICE paper, which is described in A.Rennings et al.'S paper "Extended Composite Rihgt / Left-Handed (E-CRLH) Metamaterial and its Application as Quadband Quarter-Wavelength Transmission Line". have.

In addition, as an antenna circuit including a passive circuit device using a metamaterial phenomenon, it has been applied to the Republic of Korea Patent Publication No. 10-0782301 and 10-2008-0038552.

An object of the present invention to solve the above problems is to provide a phase adjuster that can reduce the physical size by using a metamaterial element.

Further, another object of the present invention is to provide a phase adjuster that is easy to fine tune in a manufacturing process.

In the present invention, the phase adjuster is implemented with devices using metamaterial phenomena, and aims at an improved effect.

According to an embodiment of the present invention, a phase adjuster includes: an input impedance unit having a signal input to one end and having a resistance component and a negative capacitance component; A first transmission line, one end of which is connected to the other end of the input impedance unit and through which the signal passes; A second transmission line having one end connected to the other end of the first transmission line and through which the signal passes; An output impedance unit having one end connected to the other end of the second transmission line, the signal being output to the other end, and having a resistance component and a negative capacitance component; And a ground admittance unit having one end connected to the connection node of the first transmission line and the second transmission line, the other end connected to the ground, and having a resistance component and a negative inductance component.

Preferably, the sum of the lengths of the first transmission line and the second transmission line may be shorter than λ / 4. (Λ: wavelength of the signal passing through the phase adjuster)

Preferably, the input impedance unit, the first transmission line, the second transmission line, and the output impedance unit have a symmetrical structure with respect to the connection node of the first transmission line and the second transmission line.

Preferably, the input impedance unit or the output impedance unit may include a variable capacitor, and the ground admittance unit may include a variable inductor.

A phase adjuster according to another embodiment of the present invention for achieving the above object, a substrate; A transmission line in the form of a strip covered over the substrate; An inductance strip connected to a side of the transmission line and at least partially connected to ground; A first air gap disposed at an input of the transmission line and physically spaced apart from the transmission line at intervals through which an AC signal can pass; And a second gap located at an output end of the transmission line and physically spaced apart from the transmission line at intervals through which an AC signal can pass.

Preferably, the length of the transmission line may be shorter than λ / 4. (Λ: wavelength of the signal passing through the phase adjuster)

Preferably, the inductance strip may be integrally formed with the transmission line.

If the phase adjuster according to the embodiment of the present invention is implemented using a conventional material, the length of the transmission line cannot be shorter than λ / 2, but according to the spirit of the present invention, the phase adjuster is implemented using a metamaterial. In other words, it can be implemented with a length shorter than λ / 4. Accordingly, there is an advantage that the physical size of the phase adjuster can be significantly reduced.

In addition, according to another embodiment of the present invention, there is an advantage that the phase adjuster having a metamaterial can be implemented in a substrate-type structure that is easy to manufacture in a semiconductor manufacturing process or the like.

1 shows a circuit of a phase adjuster implemented using a variable capacitor and a variable inductor.

The illustrated phase adjuster 100 includes an input impedance section, a first transmission line 32, a second transmission line 34, and an output impedance section in the order in which signals are transmitted, and the first transmission line 32. And a ground admission part is connected between the connection node of the second transmission line 34 and the ground voltage terminal.

The input impedance unit includes a first resistor 22 to which a signal is input at one end, and one end thereof is connected to the other end of the first resistor 22, and the other end thereof is connected to the first transmission line 32. And a first capacitor 24 having a capacitance of.

The output impedance part, one end is connected to the second transmission line 34, the second capacitor 42 having a negative (-) capacitance, and one end is connected to the other end of the second capacitor 42, the other end And a second resistor 44 for outputting a signal.

The ground admittance unit includes a third resistor 52 and an inductor 54 connected in parallel thereto and having a negative inductance.

When a circuit having the structure shown in FIG. 1 is provided with a capacitor having a positive capacitance and an inductor having a positive inductance as in the prior art, the lengths of the first transmission line and the second transmission line should be at least. λ / 2 or more. Therefore, there is an obstacle in miniaturizing the phase adjuster.

In the meantime, when the capacitors 24 and 42 having a negative capacitance and the inductor 54 having a negative inductance are implemented by using a metamaterial phenomenon, the first transmission line The lengths of the 32 and the second transmission line 34 can be adjusted to be lambda / 4 or less, preferably lambda / 12 or so. As a result, the phase adjuster can be miniaturized.

Of course, an active device may be used to implement a capacitor having a negative capacitance and an inductor having a negative inductance. However, the active element itself takes up a considerable size and causes other problems such as increased cost due to the active element implementation and concern about deterioration of noise characteristics due to the active element.

In the figure, the first capacitor 24 is a variable capacitor and the inductor 54 is a variable inductor. In such a configuration, there is an advantage that the phase adjuster can be tuned for a desired use according to the frequency and phase of the signal.

When the sum of the lengths of the first transmission line 32 and the second transmission line 34 is λ / 12, the negative capacitance C ₀ and the negative inductance L ₀ are represented by the following equation. Can be determined by one.

d: length of transmission line

k: phase constant

ω: each frequency of the input signal

ω _φ : phase to be adjusted

In order to implement the capacitors 24 and 42 having the negative capacitance and the inductor 54 having the negative inductance of FIG. 1, materials and / or structures in which metamaterial phenomenon may occur should be applied. . In FIG. 2, the phase adjuster circuit of FIG. 1 is implemented as a substrate type structure that is easy to manufacture and may generate a metamaterial phenomenon.

The phase adjuster 100 'shown in FIG. 2A includes a substrate 10; A transmission line (30 ') in the form of a strip covered over the substrate (10); An inductance strip 50 'connected to a side of the transmission line 30' and at least partially connected to ground; A first air gap 20 'positioned at an input of the transmission line 30' and physically spaced apart from the transmission line 30 'at intervals through which an AC signal can pass; And a second air gap portion 40 'positioned at an output end of the transmission line 30' and physically spaced apart from the transmission line 30 'at intervals through which an AC signal can pass. .

The transmission line 30 'may have a thin strip shape to serve as a waveguide for a high frequency signal, and a length between the first air gap 20' and the second air gap 40 'may be By the metamaterial phenomenon according to the idea of the present invention, it can be λ / 4 or less and suitably about λ / 12.

When the inductance strip 50 'is integrally formed with the transmission line 30', it is preferable to reduce the manufacturing process / time, and it is symmetrical to connect to the central side of the transmission line 30 '. This is preferable because of easy operation such as impedance matching.

The substrate 10 may include a ground plane serving as a ground, and the transmission line 30 ′ may be formed to be insulated from the ground plane through the insulating layer 60 as shown in FIG. 2B. In this case, the inductance strip 50 'is preferably formed on the ground plane. In this structure, the inductance according to the length of the inductance strip 50 'in the present invention, as shown in Figure 4a is cut off the end of the inductance strip 50' by adjusting the length (trimming) inductance There is an advantage that can be fine tuned (tunning). Accordingly, the inductance strip 50 ′ may replace the variable inductor 54 of FIG. 1. 2A and 2B, the substrate 10 itself serves as a ground plane, and the transmission line 30 ′ and the substrate 10 are insulated with an insulating layer 60.

The first gap portion 20 'and the second gap portion 40' preferably have an overlapped comb shape as shown in FIG. 3 to obtain sufficient capacitance characteristics with a small area. That is, comb pattern patterns 300 and 310 having a plurality of comb patterns 302 and 312 are formed on left and right sides of the first gap portion 20 ', respectively, and a plurality of comb pattern patterns 300 and 310 are formed. It is preferable to allow the dog comb patterns 302 and 312 to be alternately arranged. In addition, the second gap portion 40 'is preferably formed in the same shape as the first gap portion 20' so as to have a predetermined capacitance. In addition, in this structure, the capacitance has a length along the length of the plurality of comb patterns 302 and 312 facing each other, and the capacitance is finely adjusted according to the degree of cutting the ends of the plurality of comb patterns 302 and 312 ( There are also advantages to tunning. Accordingly, the first gap portion 20 ′ and the second gap portion 40 ′ may replace the variable capacitors 24 and 42 of FIG. 1.

FIG. 4B shows the structure of an inductance strip of another structure that may be substituted with the inductance strip of FIG. 2A. In this case, since a ground line is formed on the substrate 10, and an end of the inductance strip 50 ′ is connected to the ground line, the inductance without completely cutting off the end of the inductance strip 50 ′. The groove 400 may be formed in a portion of the strip 50 ′ to fine tune the inductance of the inductance strip 50 ′.

Compared with FIG. 1, it can be seen that no three resistance elements exist in the structure of FIG. 2A. The resistance component of the conductor and the resistance component of the input / output terminals forming the first void portion 20 'and the second void portion 40' serve as the first resistor 22 and the second resistor 42. Since the resistance component of the inductance strip 50 'plays the role of the third resistor 52, the implementation of the independent resistance element is omitted in order to simplify the manufacturing process and reduce the cost.

Since the phase adjuster structure of FIG. 2 has a planar stacked structure, it is easy to manufacture using an existing semiconductor manufacturing process and the like, and has an advantage of miniaturization.

The phase adjuster of FIG. 2 may be used for beam adjustment in a smart antenna or the like, or may be used for phase deviation adjustment in a power amplifier or the like.

Although the technical spirit of the present invention has been described in detail according to the above-described preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

1 is a circuit diagram showing a phase adjuster according to an embodiment of the present invention.

Figure 2a is a perspective view showing a phase adjuster according to another embodiment of the present invention

FIG. 2B is a cross sectional view taken along line AA ′ in FIG. 2A;

3 is shaved flat showing the detailed structure of the air gap portion Figure 2a.

Figure 4a is a flat razor illustrating the detailed structure of the inductance strip of Figure 2a.

Figure 4b shows a detail structure of the inductance of the strip other structure which may be substituted and the inductance of the strips of flat shaving Figure 2a.

Description of the Related Art

10: substrate 20 ': first gap portion

22: first resistor 24: first capacitor

30 ': transmission line 32: first transmission line

34: second transmission line 40 ': second void

42: second resistor 44: second capacitor

50 ': inductance strip 52: third resistor

54: inductor

Claims (13)

An input impedance unit to which a signal is input at one end; A first transmission line, one end of which is connected to the other end of the input impedance unit and through which the signal passes; A second transmission line having one end connected to the other end of the first transmission line and through which the signal passes; An output impedance unit having one end connected to the other end of the second transmission line and outputting a signal to the other end; And And a ground admittance unit having one end connected to the connection node of the first transmission line and the second transmission line and the other end connected to the ground. Each of the input impedance unit and the output impedance unit; resistance; And A capacitor having a negative capacitance component; The ground admittance unit; resistance; And And an inductor having a negative inductance component. The inductor of claim 1, further comprising: an inductor of the ground admittance unit; A phase adjuster characterized in that the inductance is a finely tuned inductor. The method of claim 2, The tuning inductor, And a line shape having the transmission line and the ground voltage terminal as a medium, and having a length adjusted by a trimming process to adjust a final inductance. The method of claim 1, wherein the input impedance unit and the capacitor of the output impedance unit; A phase adjuster characterized in that the tuning capacitor adjusted the value of the capacitance. The method of claim 4, wherein the tuning capacitor; A comb pattern having a plurality of comb patterns on one side and the other side is formed, respectively, and each of the plurality of comb patterns of the comb pattern formed on the other side is inserted between the plurality of comb patterns of the comb pattern formed on the one side. And a length of the plurality of comb-patterns is adjusted by a trimming process to adjust a final capacitance. The method of claim 1, The sum of the lengths of the first transmission line and the second transmission line is shorter than lambda / 4. (λ: wavelength of the signal passing through the phase adjuster) Board; A transmission line in the form of a strip covered over the substrate; An inductance strip connected to a side of the transmission line and at least partially connected to ground; A first air gap disposed at an input of the transmission line and physically spaced apart from the transmission line at intervals through which an AC signal can pass; And Located at the output terminal of the transmission line, the second air gap portion for physically spaced apart the transmission line at an interval through which the AC signal can pass; The inductance strip; resistance; And An inductor having a negative inductance component; Each of the first void portion and the second void portion; A comb pattern having a plurality of comb patterns is formed on one side and the other side, respectively, and each of the plurality of comb patterns of the comb pattern formed on the other side is inserted between the plurality of comb patterns of the comb pattern formed on the one side. Phase adjuster. The method of claim 7, wherein And the length of said transmission line is shorter than [lambda] / 4. (λ: wavelength of the signal passing through the phase adjuster) The method of claim 7, wherein And the inductance strip is formed integrally with the transmission line. The method of claim 7, wherein The substrate includes a ground plane serving as ground, The transmission line is formed to be insulated from the ground plane through an insulating layer, The inductance strip is formed on the ground plane. The method of claim 10, wherein the inductance strip; Phase inductor, characterized in that the final inductance is adjusted by cutting the end to adjust the length. delete The method of claim 7, wherein And a final capacitance of the first gap portion or the second gap portion is adjusted by cutting the end portions of the plurality of comb patterns.

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