CN112768852B - Folded substrate integrated waveguide phase shifter with CSRR loaded periodically - Google Patents
Folded substrate integrated waveguide phase shifter with CSRR loaded periodically Download PDFInfo
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- 239000000758 substrate Substances 0.000 title claims abstract description 7
- 239000002184 metal Substances 0.000 claims abstract description 37
- 230000010363 phase shift Effects 0.000 claims abstract description 23
- 230000000694 effects Effects 0.000 claims abstract description 4
- 238000003491 array Methods 0.000 claims description 14
- 230000008878 coupling Effects 0.000 claims description 4
- 238000010168 coupling process Methods 0.000 claims description 4
- 238000005859 coupling reaction Methods 0.000 claims description 4
- 238000005530 etching Methods 0.000 claims description 3
- 230000000149 penetrating effect Effects 0.000 claims description 3
- 230000002596 correlated effect Effects 0.000 claims description 2
- 230000005672 electromagnetic field Effects 0.000 claims description 2
- 230000000737 periodic effect Effects 0.000 claims description 2
- 230000005855 radiation Effects 0.000 abstract description 4
- 238000004088 simulation Methods 0.000 description 6
- 238000003780 insertion Methods 0.000 description 4
- 230000037431 insertion Effects 0.000 description 4
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- 238000005516 engineering process Methods 0.000 description 2
- 238000007142 ring opening reaction Methods 0.000 description 2
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
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- H01P1/182—Waveguide phase-shifters
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Abstract
The invention discloses a folded substrate integrated waveguide phase shifter for periodically loading CSRR, which comprises FSIW and CSRR which is periodically arranged. Has the following advantages: CSRR is loaded on the middle metal layer of FSIW, so that the shielding property of FSIW is kept, and the radiation loss of CSRR is avoided; the CSRR in the FSIW has a strong loading effect, and the required phase shift can be realized only by a small number of CSRR units, so that the size of the phase shifter is reduced; the FSIW and the slow wave structure do not need a switching structure, are easy to integrate with other FSIW-based circuits, and can be directly embedded into the existing FSIW system.
Description
Technical Field
The invention belongs to the technical field of microwaves, and relates to a Folded Substrate Integrated Waveguide (FSIW) phase shifter of a periodically loaded Complementary Split Resonant Ring (CSRR).
Background
The phase shifter is an indispensable key device in a beam forming network and is required to have the characteristics of wide band, good phase shift flatness, low loss, good amplitude balance, easiness in integration with other circuits and the like. At present, most broadband phase shifters are realized based on micro-strips or E-plane waveguides, the former has large loss in a microwave high-frequency band due to an open structure, and the latter has the problems of complex processing, large volume, high cost, difficulty in integration with a planar circuit and the like although the loss is small. As a planar waveguide structure, the Substrate Integrated Waveguide (SIW) realizes perfect compromise between high-performance metal waveguide and low-cost planar transmission line, and has the advantages of low cost, low profile, low loss, easy integration with other planar circuits and the like. However, in some applications, the size of the SIW is still too large, and in order to further reduce the size, the half-mold SIW (hmsiw) and the folding SIW (fsiw) have come into play. With the development of SIW technologies (including SIW, HMSIW and FSIW, etc.), SIW phase shifters have also received great attention.
The most direct SIW phase shifter is a SIW equal-width unequal-length phase shifter, namely, a phase shifting function is realized by using a SIW delay line, but the SIW phase shifter is very sensitive to frequency, has narrow working bandwidth and is greatly limited in application. Another commonly used SIW phase shifter is the SIW equal-length unequal-width phase shifter, which utilizes the approximately parallel phase constants of SIWs of different widths to achieve a flat phase shift with a relative bandwidth of about 10%, but this is still insufficient for wideband applications. In order to further expand the working bandwidth of the SIW phase shifter, the SIW equal-length unequal-width phase shifter and the SIW equal-width unequal-length phase shifter can be organically combined to construct the SIW self-compensation phase shifter, but the physical length of the phase shifter is inconsistent with that of a reference line, so that the structure is asymmetric, and the integration and the application of the phase shifter in a beam forming network are influenced. Another method is to embed a dielectric block having a dielectric constant different from that of the board material in the SIW to change the equivalent dielectric constant of the SIW transmission line, thereby changing the phase velocity of signal propagation. However, this structure is not only complicated to manufacture, but also occupies a large area. In addition, a broadband phase shift function can also be realized by periodically loading Complementary Split Resonant Rings (CSRR) on the metal surface of the SIW or HMSIW. However, such a surface etching structure destroys the shielding property of the SIW, increases the radiation loss of the phase shifter, and deteriorates the amplitude balance between the phase shifter and the reference line.
In the aspect of FSIW phase shifters, only FSIW equal-width unequal-length phase shifters and FSIW equal-width unequal-length phase shifters are reported at present, and no phase shifter related technology report for loading CSRR structures on FSIW exists.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides an FSIW phase shifter for periodically loading CSRR on an FSIW intermediate metal layer, which not only has small size and can realize flat phase shift in a wide frequency band, but also has the characteristic of complete shielding, and avoids the radiation loss of CSRR.
The invention adopts the following technical scheme:
the invention provides an FSIW phase shifter for periodically loading CSRR, which comprises FSIW and a plurality of CSRR which are periodically arranged;
the FSIW is composed of a top metal layer, a first medium layer, a middle metal layer, a second medium layer, a bottom metal layer and two rows of metallized through hole arrays penetrating through the first medium layer and the second medium layer, wherein the top metal layer, the first medium layer, the middle metal layer, the second medium layer and the bottom metal layer are arranged in sequence from top to bottom;
the distance W between the two rows of the metallized through hole arrays is the width of FSIW, and the cut-off frequency of FSIW is determined; one side of the middle metal layer is connected with one row of the metalized through hole arrays, the edge of the other side of the middle metal layer is not contacted with the other row of the metalized through hole arrays, and the distance g between the two rows of the metalized through hole arrays is 0.125W;
the CSRR in periodic arrangement is etched on a middle metal layer of the FSIW and comprises an outer ring gap and an inner ring gap with opposite openings;
preferably, the outer ring slot opening of the CSRR is towards the edge of the middle metal layer that is not in contact with the metalized via array;
preferably, the distance between the inner ring gap and the outer ring gap of the CSRR in the x-axis direction is 0;
preferably, the equivalent circuit of CSRR is a parallel LC loop with an equivalent inductance LrAnd an equivalent capacitance value CrLength L of gap with outer ringR1And length L of inner ring gapR2Positively correlated with the width W of the outer ring gapR1And width W of inner ring gapR2Negative correlation; therefore, the resonant frequency of the CSRR can be effectively controlled by adjusting the length and the width of the outer ring gap and the inner ring gap
Making it work in the working frequency band needed by the phase shifter;
preferably, the coupling strength between FSIW and CSRR can be varied by varying LS1And S2The coupling strength between adjacent CSRRs can be adjusted by changing S1Carrying out adjustment; wherein L isS1The outer ring gap opening length, S, of CSRR1Denotes the distance, S, between adjacent CSRRs2Representing the distance between the outer ring gap opening of the CSRR and the edge of the middle metal layer;
preferably, the number of CSRRs is determined by the required phase shift value, and the phase shift value can be improved by increasing the number of CSRRs;
preferably, the first dielectric layer and the second dielectric layer are both TanconicTLY-5 dielectric substrates with the relative dielectric constant of 2.2, the loss tangent of 0.0009 and the thickness of 0.5 mm;
more preferably, the working frequency band of the FSIW phase shifter is set to 12.5GHz, the phase shift is 90 degrees, and the number of CSRRs is 3. The specific geometric parameters are as follows: w6.4, g 0.8, S1＝0.2,S2＝0.9,WR1＝0.3,WR2＝0.2,LR1＝11.8,LR2＝7.7,LS1＝2,LS21.3 (unit: mm)
The working principle is as follows:
the CSRR essentially behaves as an electric dipole, and etching of the periodically arranged CSRR on the intermediate metal layer of FSIW can act as a master mode (TE) for FSIW10Mode) produces a strong loading effect that changes the electromagnetic field distribution in the FSIW so that it is concentrated near the CSRR. The FSIW region of the periodically loaded CSRR has a smaller phase velocity than the FSIW of the unloaded CSRR and can therefore be considered as a slow wave structure. Moreover, since the phase velocities of the FSIW of the periodically loaded CSRR and the FSIW of the unloaded CSRR are approximately parallel, the two have flat phase difference in a wide frequency band under the same physical length. The phase shift can be reduced by changing the size of the CSRR (reducing the distance D between the inner ring gap opening and the outer ring gap of the CSRR in the y-axis direction12Length L of inner ring gapR2The phase shift value increases; increase the opening length L of the outer ring gapS1The phase shift value is increased) and the number (the number of CSRRs is increased to increase the phase shift value).
The invention has the following advantages:
(1) CSRR is loaded on the middle metal layer of FSIW, so that the shielding property of FSIW is kept, the radiation loss of CSRR is avoided, and the amplitude balance between the CSRR and reference FSIW is good;
(2) the CSRR in the FSIW has a strong loading effect, and the required phase shift can be realized only by a small number of CSRR units, so that the design complexity is reduced, and the size of the phase shifter is reduced;
(3) the FSIW and the slow wave structure do not need a switching structure, are easy to integrate with other FSIW-based circuits, and can be directly embedded into the existing FSIW system.
Drawings
FIGS. 1(a) and (b) are top and side views, respectively, of the present invention;
FIG. 2 is a phase shift simulation result of the present invention;
FIG. 3 is the S-parameter simulation result of the present invention.
Fig. 4 is a comparison of insertion loss simulation results between FSIW loaded with CSRR and FSIW unloaded with CSRR.
Detailed Description
The present invention will be further described with reference to the accompanying drawings.
As shown in fig. 1(a) and (b), the FSIW phase shifter for periodically loading CSRR provided by the present invention comprises: FSIW1 and CSRR 2 arranged periodically; the FSIW1 consists of a top metal layer 3, a first medium layer 4, a middle metal layer 5, a second medium layer 6, a bottom metal layer 7 and two rows of metallized through hole arrays 8 penetrating through the first medium layer 4 and the second medium layer 6; the distance W between the two rows of metallized through hole arrays 8 is the width of FSIW, and the cut-off frequency of FSIW is determined; one side of the middle metal layer 5 is connected with one row of the metalized through hole arrays, and the distance g between the edge of the other side and the other row of the metalized through hole arrays is 0.125W;
the CSRR 2 arranged periodically is etched on the middle metal layer 5 of the FSIW1, and the distance between the adjacent CSRR is S1The distance between CSRR and the edge of intermediate metal layer 5 is S2(ii) a The CSRR unit comprises an outer ring gap 2a and an inner ring gap 2 b; the length of the outer ring gap 2a is LR1Width of WR1The length of the ring opening is LS1(ii) a The length of the inner ring gap 2b is LR2Width of WR2The length of the ring opening is LS2(ii) a The distance between the inner ring gap 2a and the outer ring gap 2b in the x-axis direction is 0, and the distance in the y-axis direction is D12. The specific geometric parameters are as follows: w6.4, g 0.8, S1＝0.2,S2＝0.9,WR1＝0.3,WR2＝0.2,LR1＝11.8,LR2＝7.7,LS1＝2,LS21.3 (unit: mm).
Fig. 2 is a simulation result of phase shift of the present invention. In this example, the FSIW phase shifter of the periodically loaded CSRR has a center frequency of 12.5 GHz. The flat phase shift of 90 +/-4 degrees is realized in the frequency range of 10.3-15GHz, the phase shift bandwidth is as high as 37.6 percent, and the excellent phase shift performance is shown.
FIG. 3 is the S-parameter simulation result of the present invention. As can be seen, the insertion loss of the phase shifter is within the whole working frequency band (10-15GHz)|S21Less than 0.29dB, return loss (| S)11|) is better than 23 dB. It is verified that the FSIW of the periodically loaded CSRR can be directly connected with the common FSIW without any switching structure.
FIG. 4 shows the insertion loss (| S) between FSIW loaded with CSRR and FSIW unloaded with CSRR21|) simulation results. It can be seen from the graph that the maximum difference between the two is only 0.02db in the frequency range of 10.5-15 GHz. It was verified that CSRR loaded at FSIW intermediate metal layer has almost no radiative losses. Compared with the existing SIW and HMSIW phase shifters periodically loaded with CSRR, the invention obtains lower insertion loss.
The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.
Claims (9)
1. The folded substrate integrated waveguide phase shifter for periodically loading the CSRR is characterized by comprising FSIW and a plurality of CSRR which are periodically arranged;
the FSIW is composed of a top metal layer, a first medium layer, a middle metal layer, a second medium layer, a bottom metal layer and two rows of metallized through hole arrays penetrating through the first medium layer and the second medium layer, wherein the top metal layer, the first medium layer, the middle metal layer, the second medium layer and the bottom metal layer are arranged in sequence from top to bottom;
one side of the middle metal layer is connected with one row of the metalized through hole arrays, and the edge of the other side of the middle metal layer is not contacted with the other row of the metalized through hole arrays;
the CSRR in periodic arrangement is etched on a middle metal layer of the FSIW and comprises an outer ring gap and an inner ring gap with opposite openings;
the outer ring gap opening of the CSRR faces the edge of the middle metal layer which is not contacted with the metalized through hole array; the distance between the inner ring gap and the outer ring gap in the x-axis direction is 0.
2. The phase shifter of claim 1, wherein the side of the middle metal layer not in contact with the array of metallized vias is spaced from the array of metallized vias by a distance g = 0.125W, W representing the distance between two rows of arrays of metallized vias.
3. The phase shifter of claim 1, wherein the distance W between the two rows of metallized via arrays is the width of FSIW, which determines the cutoff frequency of FSIW.
4. The phase shifter of claim 1, wherein the equivalent circuit of the CSRR is a parallel LC loop with an equivalent inductance LrAnd an equivalent capacitance value CrLength L of gap with outer ringR1And length L of inner ring gapR2Positively correlated with the width W of the outer ring gapR1And width W of inner ring gapR2Negative correlation; the resonant frequency of CSRR is controlled by adjusting the length and width of the outer ring gap and the inner ring gap
So that it operates within the desired operating frequency band of the phase shifter.
5. The phase shifter of claim 1 or 4, wherein the coupling strength between FSIW and CSRR is changed by changing LS1And S2Adjusted so that the coupling strength between adjacent CSRRs is changed by changing S1Carrying out adjustment; wherein L isS1The outer ring gap opening length, S, of CSRR1Denotes the distance, S, between adjacent CSRRs2The distance between the outer ring slot opening of the CSRR and the edge of the middle metal layer is shown.
6. The phase shifter of claim 1, wherein the size and number of the CSRRs determine the magnitude of the phase shift value.
7. The phase shifter of claim 6, wherein the distance D between the inner ring slot opening and the outer ring slot of the CSRR in the y-axis direction is reduced12Length L of inner ring gapR2The phase shift value increases; increase the opening length L of the outer ring gapS1The phase shift value increases; increasing the number of CSRRs increases the phase shift value.
8. The phase shifter of claim 1, wherein the FSIW phase shifter has an operating band of 12.5GHz, a phase shift of 90 degrees and 3 CSRRs.
9. The phase shifter of claim 1, wherein the CSRR is substantially an electric dipole, and etching the periodically arranged CSRR in the middle metal layer of the FSIW couples the fundamental mode TE of the FSIW10The mode produces a strong loading effect that changes the electromagnetic field distribution in the FSIW so that it is concentrated near the CSRR.
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| US9019160B2 (en) * | 2013-03-18 | 2015-04-28 | King Fahd University Of Petroleum And Minerals | CSRR-loaded MIMO antenna systems |
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| CN107591595B (en) * | 2017-07-18 | 2019-10-01 | 电子科技大学 | Bimodulus reconfigurable filter based on half module substrate integrated wave guide and CSR structure |
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| CN109830789B (en) * | 2019-01-25 | 2020-08-14 | 南京邮电大学 | Broadband band-pass filter based on folded substrate integrated waveguide and complementary split ring resonator |
| CN110389259B (en) * | 2019-07-30 | 2021-06-04 | 重庆邮电大学 | Solid material dielectric constant sensor based on SIW-CSRR structure |
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