CN212085184U

CN212085184U - SIW filter and HMSIW filter

Info

Publication number: CN212085184U
Application number: CN201921145341.2U
Authority: CN
Inventors: 董元旦; 朱谊龙; 杨涛
Original assignee: Chengdu Pinnacle Microwave Co Ltd
Current assignee: Chengdu Pinnacle Microwave Co Ltd
Priority date: 2019-07-19
Filing date: 2019-07-19
Publication date: 2020-12-04
Anticipated expiration: 2029-07-19

Abstract

The utility model discloses a SIW filter and HMSIW filter based on even impedance resonator loading, including the base plate, the base plate includes upper surface and lower surface, still includes the microstrip line structure; the upper surface of the substrate is provided with an SIW structure or an HMSIW structure, and a rectangular groove is etched in the middle of the SIW structure or the HMSIW structure to form a uniform impedance resonator; the uniform impedance resonator and the microstrip line structure form two half-wavelength resonators or quarter-wave resonators with short-circuited terminals on the surface of the substrate, and form a second-order band-pass filter. The invention can realize the miniaturization and the wide stop band inhibition performance.

Description

SIW filter and HMSIW filter

Technical Field

The utility model relates to a wireless communication technology field particularly, relates to a SIW wave filter and HMSIW wave filter based on even impedance syntonizer loading.

Background

Because of its excellent performance, the Substrate Integrated Waveguide (SIW) filter not only maintains the advantages of high Q value and low insertion loss of the traditional Waveguide filter, but also has the characteristics of low profile, easy processing, easy integration and the like of the PCB circuit; in the microwave and millimeter wave field, the SIW filter has a wide application prospect. SIW filters of various forms and with different functions have been used in various types of radio frequency microwave systems, such as wireless communication, radar, remote sensing, aerospace, and the like. Particularly in the field of mobile communication, with the regardless of innovation of technologies, the 4G and 5G communication technologies are increasingly developed, and with the wide popularization of the future internet of things, the demand for the filter will further increase, which will inevitably put higher requirements on the performance of the filter, such as miniaturization, integration, high selectivity, multi-pass band, reconfigurability, and the like.

In the aspect of the miniaturization design of the SIW filter, the mainstream miniaturization technology mainly includes: 1/n die cutting technology, multilayer folding technology and loading technology. The SIW filter based on the 1/n die cutting technology is characterized in that the SIW filter is cut along the central line of a whole SIW die, and the cut surface of the SIW filter is equivalent to a virtual magnetic wall. The cut filter can not only keep the transmission characteristic of the original mode, but also reduce the volume. In the miniaturization research of mode cutting, the half-mode SIW and the quarter-mode SIW are mainly used, so that the filter area is respectively reduced by half and quarter. In addition, SIW miniaturization by one-eighth and one-sixteenth modes has been studied. The SIW filter based on the multi-layer folding technology is obtained by folding a plurality of single-layer PCB circuits through a horizontal symmetrical plane, so that the area of the filter is sharply reduced under the condition of slightly increasing the section. The area is reduced by half by adopting a double-layer folding mode. The SIW filter based on the loading technology is miniaturized, and the principle is that a metal or metamaterial structure is loaded to disturb field distribution in an SIW resonant cavity, so that the resonant frequency is reduced, and the miniaturization is realized. For example, by using metamaterial loading, a Complementary Split-Ring Resonator (CSRR) is used as a magnetic metamaterial, and loading the magnetic metamaterial on the surface of the SIW resonant cavity can effectively break through the cut-off frequency of the SIW, so that the SIW resonant cavity resonates below the cut-off frequency of the SIW, thereby realizing miniaturization.

The SIW filter based on the 1/n die cutting technology is miniaturized, and most of characteristics of the waveguide filter are still reserved. The waveguide filter has the obvious defect that the higher-order mode resonant frequency is relatively close to the main mode resonant frequency, so that a plurality of parasitic pass bands are formed outside the pass band of the filter, the out-of-band rejection performance of the filter is reduced, and the overall performance of the filter is reduced.

The SIW filter based on the multilayer folding technology has a double-layer or even multilayer circuit structure, so that the processing technology is complex, and the multiple folding is sensitive to the processing precision, thereby providing higher requirements for processing and manufacturing and increasing the cost.

The miniaturization of SIW filters based on loading techniques also faces the problem of spurious passbands generated by higher order modes. For example, the SIW filter loaded based on the CSRR can break through the cut-off frequency of the SIW filter and form a pass band below the cut-off frequency; but TE due to SIW₁₀₁Propagation of the mode instead causes the master mode TE of the SIW₁₀₁The modes form parasitic passbands and thus affect the overall out-of-band rejection performance of the filter.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a SIW filter based on even Impedance Resonator loading through at SIW surface etching even Impedance Resonator (Uniform Impedance Resonator, UIR) structure, constitutes the band pass filter of a second order from this to can realize wide stop band rejection performance.

In order to achieve the technical purpose, the utility model discloses a technical scheme specifically as follows:

a SIW filter based on uniform impedance resonator loading comprises a substrate, wherein the substrate comprises an upper surface and a lower surface and also comprises a microstrip line structure; the upper surface of the substrate is provided with an SIW structure, and a rectangular groove is etched in the middle of the SIW structure to form a uniform impedance resonator; the uniform impedance resonator and the microstrip line structure form two half-wavelength resonators with short-circuited terminals on the surface of the substrate, and form a second-order band-pass filter.

Further, the uniform impedance resonator is an elongated rectangle, and the resonance frequency is controlled by the length of the uniform impedance resonator and the width of the SIW structure.

Furthermore, the microstrip line structure comprises a microstrip line serving as an input end and an output end, a coupling feeder is arranged at one end of the microstrip line close to the SIW structure, and the coupling feeder is perpendicular to the microstrip line structure.

Further, a distance is left between the coupling feed line and the SIW structure, and an external quality factor is controlled by the distance and the length of the coupling feed line.

Furthermore, a plurality of metalized through holes are formed in the two ends of the substrate, and the upper surface and the lower surface of the substrate are connected through the metalized through holes.

The utility model also discloses a HMSIW (Half mode Substrate Integrated Waveguide) wave filter based on even impedance syntonizer loading can reduce the wave filter size, realizes the wave filter equally and connects wide stop band rejection performance.

An HMSIW filter based on uniform impedance resonator loading, characterized by: the micro-strip line structure comprises a substrate and an HMSIW structure arranged on the substrate, wherein micro-strip line structures are arranged on two sides of the HMSIW structure; a rectangular groove is etched in the middle of the HMSIW structure to form a uniform impedance resonator; the uniform impedance resonator and the microstrip line structure form two short-circuited quarter-wave resonators, thereby forming a second-order filter.

Further, the uniform impedance resonator is an elongated rectangle, and the resonant frequency is controlled by the length of the uniform impedance resonator and the width of the HMSIW structure.

Furthermore, the microstrip line structure comprises a microstrip line serving as an input end and an output end, a coupling feeder is arranged at one end of the microstrip line close to the HMSIW structure, and the coupling feeder is perpendicular to the microstrip line structure.

Furthermore, a plurality of metalized through holes are formed in one end of the substrate, and the upper layer and the lower layer of the substrate are connected through the metalized through holes.

The beneficial effects of the utility model reside in that: the utility model is different from the prior art, the utility model provides a two kinds of technical scheme, the first scheme is based on the SIW structureSIW miniaturization scheme based on UIR loading. By etching UIR structure on the surface of SIW, SIW is equivalent to a half-wavelength resonator with two short-circuited terminals, thereby forming a second-order filter. The center frequency of the filter can be adjusted by adjusting the broadside of the SIW and the length of the UIR; the longitudinal length of the SIW has almost no influence on the filter, so that the longitudinal length can be reduced, and the miniaturization design of the SIW filter is realized; the UIR-loaded SIW filter has a wide stop-band rejection performance. The first higher-order mode of the filter is TE₃₀₁Mode, since the longitudinal length of the SIW filter can be made small, its resonance frequency is close to 3f₀，f₀The filter can realize the wide stop band suppression performance of nearly 3 octaves for the central frequency of the filter passband.

The second scheme is to further reduce the size on the basis of the first scheme, and provides a UIR loaded HMSIW filter. By etching the UIR structure on the surface of the HMSIW, the HMSIW is equivalent to two short-circuited quarter-wave resonators, and the structure enables the filter to be reduced by half relative to the SIW, so that the miniaturization design of the filter is further realized; the UIR-loaded HMSIW filter also has wide stop-band rejection performance. Similar to the UIR-loaded SIW, this filter also has nearly 3 times the wide stop-band rejection performance. In particular, TE can be caused due to edge effects of the notch face of the half-mold substrate₃₀₁The resonant frequency of the mode is raised, thereby achieving wider stop band rejection performance.

Drawings

Fig. 1 is a schematic plan view of a SIW filter based on uniform impedance resonator loading provided by the present invention;

fig. 2 is a schematic diagram of S-parameters (5-15GHz) of the simulation and test of the SIW filter based on the loading of the uniform impedance resonator provided by the present invention;

FIG. 3 is a schematic diagram of S parameters (5-30GHz) for simulation and test of SIW filter based on loading of uniform impedance resonator provided by the present invention;

fig. 4 is a schematic plan view of an HMSIW filter based on uniform impedance resonator loading provided by the present invention;

fig. 5 is a schematic diagram of S parameters (5-15GHz) of HMSIW filter simulation and test based on uniform impedance resonator loading provided by the present invention;

fig. 6 is a schematic diagram of S-parameters (5-30GHz) of HMSIW filter simulation and test based on uniform impedance resonator loading provided by the present invention.

Reference numerals:

1. a microstrip line structure; 2. coupling a feed line; 3. a rectangular groove; 4. the vias are metallized.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

In the present invention, the terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", and the like indicate the position or positional relationship based on the position or positional relationship shown in the drawings, and are only the terms determined for convenience of describing the structural relationship of each component or element of the present invention, and are not specific to any component or element of the present invention, and are not to be construed as limiting the present invention.

The present invention will be described in further detail below with reference to specific embodiments and with reference to the accompanying drawings.

As shown in fig. 1 to 3, the first embodiment:

a SIW filter based on uniform impedance resonator loading comprises a substrate, a microstrip line structure 1 and a plurality of signal processing units, wherein the substrate comprises an upper surface and a lower surface; the upper surface of the substrate is provided with a SIW structure, and a rectangular groove 3 is etched in the middle of the SIW structure to form a uniform impedance resonator; the uniform impedance resonator and the microstrip line structure 1 form two half-wavelength resonators with short-circuited terminals on the surface of the substrate, and form a second-order band-pass filter.

The uniform impedance resonator is an elongated rectangle, and the resonance frequency is controlled by the length of the uniform impedance resonator and the width of the SIW structure.

The microstrip line structure 1 comprises microstrip lines which are used as an input end and an output end respectively, a coupling feeder 2 is arranged at one end of the microstrip line close to the SIW structure, and the coupling feeder 2 is perpendicular to the microstrip line structure 1. The coupling feed line 2 is spaced apart from the SIW structure, and the external quality factor is controlled by the spacing and the length of the coupling feed line 2.

The substrate both ends all are provided with a plurality of metallized via holes 4, and the upper and lower surface of substrate passes through a plurality of metallized via holes 4 and connects.

In practical use, this embodiment uses a Rogers5880 substrate, which has a relative permittivity of 2.2, a loss tangent of 0.0009 and a thickness of 0.508mm, and has copper-coated upper and lower surfaces and a bulk copper-coated lower surface. The upper surface is connected to the lower surface by periodic metallized vias 4 on both sides. A substrate based on the structure of a conventional SIW.

On the surface of the SIW, a slender rectangular UIR structure is etched, and metallized through holes 4 are arranged on two sides of the SIW, the diameter of the metallized through holes is 0.4mm, and the distance between the metallized through holes is 0.7 mm. The microstrip line with the characteristic impedance of 50 omega is connected with a coupling feeder 2 vertical to the microstrip line and feeds power to the SIW in a coupling mode, and the microstrip line is located in the center of the SIW. The SIW filter loaded by the UIR forms a second-order filter, the central frequency of the filter passband is 10GHz by adjusting the width of the SIW and the length of the UIR, and the distance of the coupling feed and the length of the coupling feed line 2 determine the external quality factor.

By optimizing the appropriate structural parameters, a bandpass filter response with a center frequency of 10GHz, with a bandwidth of about 1.22GHz, can be obtained as shown in fig. 2. The filter has wider stop band performance, and has out-of-band rejection performance exceeding 20dB in the range of 26GHz, as shown in simulation and test results of FIG. 3. In fig. 2 and 3, the meas curve is a test curve, and the sim curve is a simulation curve.

The size of the filter is only 0.54 lambda_g*0.15λ_g，λ_gThe waveguide is a waveguide wavelength, and the miniaturization is realized while the function is ensured.

As shown in fig. 4 to 6, the second embodiment:

a HMSIW filter based on uniform impedance resonator loading comprises a substrate and an HMSIW structure arranged on the substrate, wherein microstrip line structures 1 are arranged on two sides of the HMSIW structure; a rectangular groove 3 is etched in the middle of the HMSIW structure to form a uniform impedance resonator; the uniform impedance resonator and the microstrip line structure 1 form two short-circuited quarter-wave resonators, thus forming a second order filter.

The uniform impedance resonator is an elongated rectangle and passes through the length (n) of the uniform impedance resonator₂) And the HMSIW structure width controls the resonant frequency. The microstrip line structure 1 comprises microstrip lines which are used as an input end and an output end respectively, a coupling feeder 2 is arranged at one end, close to the HMSIW structure, of each microstrip line, and the coupling feeder 2 is perpendicular to the microstrip line structure 1.

One end of the substrate is provided with a plurality of metalized through holes 4, and the upper layer and the lower layer of the substrate are connected through the plurality of metalized through holes 4.

In practical use, the filter is obtained by cutting half of the filter along the center on the basis of an SIW filter, a UIR structure is etched on the surface of the HMSIW, and only one side of the UIR structure is provided with metalized through holes 4, the diameter of each through hole 4 is 0.4mm, and the distance between the through holes is 0.75 mm. The microstrip line (3) with the characteristic impedance of 50 omega is connected with a slender coupling feeder line 2 and feeds the HMSIW in a coupling mode. The HMSIW filter loaded by the UIR forms a second-order filter, and the central frequency of the filter resonates at 10GHz by adjusting the broadside of the HMSIW and the length of the UIR.

By optimizing the appropriate structural parameters, as shown in fig. 5, a bandpass filter response with a center frequency of 10GHz and a bandwidth of about 1.26GHz is finally obtained. As shown in FIG. 6, the filter has wider stop band rejection performance, the first parasitic passband of the filter is in a position exceeding 30GHz, and the out-of-band rejection performance is below-18 dB in 30 GHz. In fig. 5 and 6, the meas curve is a test curve, and the sim curve is a simulation curve.

In the present embodiment, the dimension is only 0.25 λ_g*0.14λ_g，λ_gIs the waveguide wavelength. Also, the suppression performance is ensured while the miniaturization is satisfied.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A SIW filter based on uniform impedance resonator loading, comprising a substrate including an upper surface and a lower surface, wherein: the device also comprises a microstrip line structure; the upper surface of the substrate is provided with an SIW structure, and a rectangular groove is etched in the middle of the SIW structure to form a uniform impedance resonator; the uniform impedance resonator and the microstrip line structure form two half-wavelength resonators with short-circuited terminals on the surface of the substrate, and form a second-order band-pass filter.

2. The uniform impedance resonator loading based SIW filter of claim 1, wherein: the uniform impedance resonator is an elongated rectangle, and the resonance frequency is controlled by the length of the uniform impedance resonator and the width of the SIW structure.

3. The uniform impedance resonator loading based SIW filter of claim 1, wherein: the microstrip line structure comprises a microstrip line serving as an input end and an output end respectively, a coupling feeder is arranged at one end of the microstrip line close to the SIW structure, and the coupling feeder is perpendicular to the microstrip line structure.

4. The uniform impedance resonator loading based SIW filter of claim 3, wherein: a distance is left between the coupling feed line and the SIW structure, and the external quality factor is controlled by the distance and the length of the coupling feed line.

5. The uniform impedance resonator loading based SIW filter of claim 1, wherein: the substrate is characterized in that a plurality of metalized through holes are formed in the two ends of the substrate, and the upper surface and the lower surface of the substrate are connected through the metalized through holes.

6. An HMSIW filter based on uniform impedance resonator loading, characterized by: the micro-strip line structure comprises a substrate and an HMSIW structure arranged on the substrate, wherein micro-strip line structures are arranged on two sides of the HMSIW structure; a rectangular groove is etched in the middle of the HMSIW structure to form a uniform impedance resonator; the uniform impedance resonator and the microstrip line structure form two short-circuited quarter-wave resonators, thereby forming a second-order filter.

7. The HMSIW filter based on uniform impedance resonator loading of claim 6, wherein: the uniform impedance resonator is elongated rectangular and the resonant frequency is controlled by the length of the uniform impedance resonator and the width of the HMSIW structure.

8. The HMSIW filter based on uniform impedance resonator loading of claim 6, wherein: the microstrip line structure comprises microstrip lines which are used as an input end and an output end respectively, a coupling feeder is arranged at one end of the microstrip line close to the HMSIW structure, and the coupling feeder is perpendicular to the microstrip line structure.

9. The HMSIW filter based on uniform impedance resonator loading of claim 6, wherein: the substrate comprises a substrate body and is characterized in that a plurality of metalized through holes are formed in one end of the substrate body, and the upper layer and the lower layer of the substrate body are connected through the metalized through holes.