A substrate integrated waveguide filter power divider with output port isolation

Abstract

The present invention discloses a substrate integrated waveguide filter power divider with output port isolation, comprising three substrate integrated waveguide resonators arranged in a product type, and a pair of hook-shaped stripline resonators loaded with resistors and arranged symmetrically back to back. Among them, two hook-shaped stripline resonators are bridged and integrated into the three substrate integrated waveguide resonators arranged in a product type, one substrate integrated waveguide resonator is coupled with two hook-shaped stripline resonators at the same time, and the two hook-shaped stripline resonators are separately coupled with the other two substrate integrated waveguide resonators. A coplanar waveguide transmission line is provided on each substrate integrated waveguide resonator. The present invention utilizes the two anti-phase path cancellations led out by a pair of hook-shaped stripline resonators loaded with resistors, and the dual-channel coupling between the two hook-shaped stripline resonators and the substrate integrated waveguide resonator, to realize a substrate integrated waveguide filter power divider that can take into account both output isolation and size utilization, and has the characteristics of broadband and low loss.

Description

Technical Field

[0001] The invention relates to a microwave communication device, in particular to a substrate integrated waveguide filter power divider. Background Art

[0002] Filters and power dividers are both indispensable components in RF circuits. Combining filters and power dividers to form a filter power divider can simultaneously realize the functions of frequency selection and power distribution in a single device, reducing the number of components and the problem of excessive size in the RF system. The filter power divider based on substrate integrated waveguide resonator is conducive to reducing losses, improving quality factors, and high-frequency operation; however, the traditional substrate integrated waveguide filter power divider has poor output port isolation due to structure, method and other reasons, which is not conducive to signal interference between channels and affects the reliability and stability of the system. Therefore, it is necessary to develop a substrate integrated waveguide filter power divider with output port isolation.

[0003] There are usually four types of existing substrate integrated waveguide filter power dividers. The first is to achieve filtering and power division by constructing the same magnetic coupling between the input substrate integrated waveguide resonator and multiple output substrate integrated waveguide resonators, but the isolation function of the output port cannot be achieved, and the working bandwidth is narrow and the size is large. The second is to extend the output port feeder and add an isolation resistor on the basis of the first, which can improve the isolation of the output port, but the isolation is insufficient, and the overall circuit size and insertion loss are increased. The third is to connect a microstrip power divider in series on the basis of the substrate integrated waveguide filter to achieve filtering power division and isolation functions, but there are problems such as low functional integration, insufficient isolation and narrow working bandwidth. The fourth is to achieve it through four substrate integrated waveguide resonators that form a ring coupling, and use anti-phase coupling to achieve isolation between the output ends of the port. The output isolation is relatively good, but the four resonators can only achieve a second-order filtering response, so the size is large and the bandwidth is narrow. Therefore, it is necessary to propose a substrate integrated waveguide filter power divider with good output isolation, high size utilization, wide bandwidth and low loss. Summary of the invention

[0004] Purpose of the invention: In view of the above-mentioned prior art, a substrate integrated waveguide filter power divider with output port isolation is proposed, which can take into account both output isolation and size utilization, that is, while obtaining better output isolation, it has a smaller size under the same order filter power divider response conditions, and also maintains broadband and low loss operation.

[0005] Technical solution: A substrate integrated waveguide filter power divider with output port isolation, comprising three substrate integrated waveguide resonators separated by metallized through-hole walls and arranged in a finished product, and a pair of hook-shaped stripline resonators loaded with resistors and arranged symmetrically back to back; two of the hook-shaped stripline resonators are bridged and integrated into the three substrate integrated waveguide resonators arranged in a pinion pattern, one substrate integrated waveguide resonator is coupled with two of the hook-shaped stripline resonators at the same time, and the two hook-shaped stripline resonators are separately coupled with the other two substrate integrated waveguide resonators; each substrate integrated waveguide resonator is provided with a coplanar waveguide transmission line, and the three coplanar waveguide transmission lines are arranged in a finished product pattern.

[0006] Furthermore, the pair of hook-shaped stripline resonators symmetrically arranged back to back include a pair of hook-shaped metal strips; the hook-shaped metal strip is arranged in the middle layer of the device, and the two ends are respectively connected to the upper and lower metal layers through a metallized blind hole; the total length of the hook-shaped metal strip is between 0.29λ0 and 0.37λ0, the length of the left oblique line is between 0.09λ0 and 0.11λ0, the length of the right oblique line is between 0.16λ0 and 0.19λ0, the length of the middle horizontal line part is between 0.04λ0 and 0.07λ0, and the spacing between the horizontal lines of the two hook-shaped metal strips is between 0.01λ0 and 0.02λ0.

[0007] Furthermore, the two ends of the resistor located on the upper layer of the device are respectively connected to a small metal patch, and then connected to the horizontal line parts of the two hook-shaped metal strips through metallized blind holes 2. The distance between the blind hole connection point and the right end of the horizontal line part of the hook-shaped metal strip is between 0.01λ0 and 0.02λ0.

[0008] Furthermore, the three substrate integrated waveguide resonators arranged in a pattern are composed of the upper and lower metal ground layers, the dielectric layer and the metallized through-hole wall; the coplanar waveguide transmission line includes a pair of back-to-back symmetrical L-shaped grooves arranged on the upper metal ground layer, and metal strips are formed between the L-shaped grooves. The horizontal length of the L-shaped groove is between 0.11λ0 and 0.17λ0, and the vertical length is between 0.05λ0 and 0.07λ0.

[0009] Furthermore, the bandwidth is adjusted by adjusting the bending degree of the hook-shaped stripline resonator.

[0010] Beneficial effects: Existing substrate integrated waveguide filter power dividers cannot take into account both output isolation and size utilization, and some technologies have the problems of narrow bandwidth and high loss. The present invention integrates a pair of resistor-loaded hook-shaped stripline resonators arranged symmetrically back to back into a substrate integrated waveguide resonator arranged in a pin-shaped pattern, and utilizes the two anti-phase paths derived from the pair of resistor-loaded hook-shaped stripline resonators to cancel each other out, and the dual-channel coupling between the two hook-shaped stripline resonators and the substrate integrated waveguide resonator to realize a substrate integrated waveguide filter power divider that can take into account both output isolation and size utilization, and has the characteristics of broadband and low loss.

[0011] Specifically, a pair of hook-shaped stripline resonators are composed of a hook-shaped metal strip and metalized blind holes at both ends, upper and lower metal grounds and a substrate, and are symmetrically distributed back to back. The total length of the hook-shaped metal strip is between 0.29λ0 and 0.37λ0, the length of the left oblique line is between 0.09λ0 and 0.11λ0, the length of the right oblique line is between 0.16λ0 and 0.19λ0, the length of the middle horizontal line is between 0.04λ0 and 0.07λ0, and the spacing between the horizontal lines of the two hook-shaped metal strips is between 0.01λ0 and 0.02λ0. This pair of hook-shaped stripline resonators can construct dual-channel coupling with a substrate-integrated waveguide resonator, can construct a path for isolation, and add a resonance point to the filter response without increasing the overall size, thereby improving size utilization and integration, and reducing loss; at the same time, the hook-shaped structure reduces the coupling between the stripline resonators and provides sufficient coupling for each of the two channels, and its bending degree can adjust the bandwidth.

[0012] Both ends of the resistor are connected to a small metal patch and are respectively connected to two hook-shaped metal strips in the middle layer through a second metallized blind hole. The distance between the second metallized blind hole and the right end of the horizontal line portion of the hook-shaped metal strip is between 0.01λ0 and 0.02λ0. By combining the resistor with a pair of hook-shaped stripline resonators, another path for isolation can be constructed. The signal anti-phase cancellation of the two paths can greatly improve the output isolation and realize the output isolation function.

[0013] The substrate integrated waveguide resonator arranged in a pattern is composed of two layers of metal ground, two layers of dielectric layers and metallized through-hole walls, wherein the non-porous area of ​​the metallized through-hole walls is mainly for the convenience of input and output coupling and the setting of a pair of hook-shaped stripline resonators. At the same time, a pair of L-shaped grooves are opened on the upper surface of each substrate integrated waveguide resonator for coplanar waveguide feeding, wherein the horizontal length of the L-shaped groove is between 0.11λ0 and 0.17λ0, and the vertical length is between 0.05λ0 and 0.07λ0, for supporting broadband matching; the three substrate integrated waveguide resonators can provide two resonance points for each of the two power division channels, contributing to the filtering function. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the top metal structure of the substrate integrated waveguide filter power divider of the present invention;

[0015] Figure 2 This is a schematic diagram of the intermediate metal structure of the substrate integrated waveguide filter power divider of the present invention;

[0016] Figure 3 This is a schematic diagram of the bottom metal structure of the substrate integrated waveguide filter power divider of the present invention;

[0017] Figure 4 The substrate integrated waveguide filter power divider of the present invention is 11 |Parameter response curve;

[0018] Figure 5 The substrate integrated waveguide filter power divider of the present invention is 21 |、|S 31 |、|S 32 |Parameter response curve. DETAILED DESCRIPTION

[0019] The present invention will be further explained below in conjunction with the accompanying drawings.

[0020] A substrate integrated waveguide filter power divider with isolated output ports comprises a top metal structure, an intermediate metal structure and a bottom metal structure, a first dielectric layer between the top metal structure and the intermediate metal structure, a second dielectric layer between the intermediate metal structure and the bottom metal structure, and a metallized through hole connecting the top metal structure and the bottom metal structure.

[0021] like Figure 1 As shown, the top metal structure is composed of a top convex metal ground 103 with three pairs of L-shaped grooves 101 and one rectangular groove 102. The protrusion of the top convex metal ground 103 faces the left side, one pair of L-shaped grooves 101 is horizontally located in the middle of the left edge of the protrusion, and the other two pairs of L-shaped grooves 101 are horizontally located at the upper middle position and the lower middle position of the right side of the top convex metal ground 103. The two L-shaped grooves in each pair of L-shaped grooves 101 are symmetrically arranged back to back, and a top metal strip 104 is formed in the middle. The length of the top metal strip 104 is between 0.11λ0 and 0.17λ0, and the vertical length of a single L-shaped groove 101 is between 0.05λ0 and 0.07λ0, where λ0 is the air wavelength corresponding to the center frequency. The rectangular groove 102 is vertically disposed at the center of the top convex metal ground 103 . A pair of small metal patches 105 and a resistor 201 are disposed in the rectangular groove 102 . Two ends of the resistor 201 are respectively connected to the small metal patches 105 .

[0022] like Figure 2As shown, the intermediate metal structure is composed of a pair of hook-shaped metal strips 301. The total length of each hook-shaped metal strip 301 is between 0.29λ0 and 0.37λ0, and it is composed of three sections, which are the left oblique line with a length between 0.09λ0 and 0.11λ0, the horizontal line with a length between 0.04λ0 and 0.07λ0, and the right oblique line with a length between 0.16λ0 and 0.19λ0. The two hook-shaped metal strips 301 are symmetrically arranged back to back, and the spacing between the two horizontal lines is between 0.01λ0 and 0.02λ0. The two ends of each hook-shaped metal strip 301 are respectively connected to the top-layer convex metal ground 103 through a metalized blind hole 1 401, and the horizontal line part of the hook-shaped metal strip 301 is connected to a small metal patch 105 in the rectangular groove 102 of the top-layer metal structure through a metalized blind hole 2 402. The distance between the second metalized blind hole 402 and the right side end of the horizontal line portion of the hook-shaped metal strip 301 is between 0.01λ0 and 0.02λ0, that is, the distance between the right oblique line inflection point of the hook-shaped metal strip 301 and the center of the second metalized blind hole 402 is between 0.01λ0 and 0.02λ0.

[0023] like Figure 3 As shown, the bottom metal structure is composed of a bottom convex metal ground 501.

[0024] The metallized through hole is composed of a metallized through hole wall 1 601, a metallized through hole wall 2 602 and a metallized through hole wall 3 603. Among them, the metallized through hole wall 1 601 is distributed along the outer edge of the top convex metal ground 103, except for each top metal strip 104, and the whole is surrounded by a convex shape. The non-hole distance of the metallized through hole wall 1 601 at each top metal strip 104 is between 0.04λ0 and 0.07λ0. The metallized through hole wall 2 602 is a through hole distributed vertically in the middle of the convex shape. The vertical middle position of the metallized through hole wall 2 602 is provided with a non-hole area with a distance between 0.08λ0 and 0.10λ0, and the above-mentioned pair of hook-shaped metal strips 301 span the non-hole area. The metallized through hole wall 3 603 is a through hole distributed horizontally in the middle of the right side of the convex structure.

[0025] In the above structure, each hook-shaped metal strip 301, metalized blind hole 1 401, top and bottom metal ground and two dielectric layers form a hook-shaped stripline resonator. Two layers of metal ground and two layers of dielectric layers, metalized through hole wall 1 601, metalized through hole wall 2 602, and metalized through hole wall 3 603 form three substrate integrated waveguide resonators. Three pairs of L-shaped slots 101, top metal strip 104, first dielectric layer, second dielectric layer, and two layers of metal ground form three coplanar waveguide transmission lines.

[0026] In the above structure, the transmission signal is fed from the coplanar waveguide transmission line on the left, and under the overall action of three substrate integrated waveguide resonators, a pair of hook-shaped stripline resonators and resistors, the power is output from a pair of coplanar waveguide transmission lines on the right, and it has filtering and output isolation functions.

[0027] In this process, the output isolation comes from the anti-phase cancellation of the two paths between the output ports. Path one is from the upper right output port to the substrate integrated waveguide resonator located at the upper right, then coupled to the upper hook-shaped stripline resonator, and transmitted to the lower hook-shaped stripline resonator through the resistor, and then coupled to the substrate integrated waveguide resonator located at the lower right, and finally to the lower right output port. Path two passes through the upper right output port, the upper right substrate integrated waveguide resonator, the upper hook-shaped stripline resonator, the left substrate integrated waveguide resonator, the lower hook-shaped stripline resonator, the lower right substrate integrated waveguide resonator and the lower right output port in sequence.

[0028] The power distribution function is mainly achieved by coupling the left substrate integrated waveguide resonator with a pair of upper and lower symmetrical hook-shaped stripline resonators at the same time, and each hook-shaped stripline resonator is coupled with the corresponding right substrate integrated waveguide resonator, wherein the strip of the hook-shaped stripline resonator must maintain a hook shape to ensure that sufficient signals are obtained on the two channels, and to reduce the mutual interference between the two power division signals, and to maintain the above-mentioned output isolation function. At this time, there are two substrate integrated waveguide resonators and one hook-shaped stripline resonator equivalently on each channel, which can achieve a third-order filtering response, and the curvature of the hook-shaped stripline resonator can adjust the bandwidth. The addition of a pair of hook-shaped stripline resonators does not increase the size of the overall circuit, but can increase the order of filtering and have an isolated power division function. Therefore, the present invention can take into account both output isolation and high size utilization, and has low loss.

[0029] Compared with the prior art, the substrate integrated waveguide filter power divider proposed in the present invention has the advantages of both output isolation and size utilization, and has the characteristics of broadband and low loss. This embodiment uses a Taconic TLY-5 substrate with the same upper and lower layers, and the circuit size is only 0.97λ0×0.93λ0. Figure 4 , Figure 5 Given this embodiment S Parameter response curve. As can be seen from the figure, the 3-dB operating bandwidth frequency range is 9.40 GHz - 10.48 GHz, that is, the relative bandwidth can reach 10.9%, the minimum insertion loss is only 1.36dB, and the three transmission poles are located at 9.55 GHz, 9.82 GHz and 10.23 GHz, that is, the third-order filtering response is achieved, and the in-band output isolation is greater than 19.3 dB.

[0030] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A substrate integrated waveguide filter power divider with output port isolation, characterized in that: The invention comprises a top metal structure, an intermediate metal structure and a bottom metal structure, wherein a first dielectric layer is provided between the top metal structure and the intermediate metal structure, and a second dielectric layer is provided between the intermediate metal structure and the bottom metal structure, and further comprises a metallized through hole connecting the top metal structure and the bottom metal structure; the invention comprises three substrate integrated waveguide resonators separated by metallized through hole walls and arranged in a finished form, and a pair of back-to-back symmetrically arranged hook-shaped strip line resonators loaded with resistance; the pair of back-to-back symmetrically arranged hook-shaped strip line resonators comprises a pair of hook-shaped metal strips, The hook-shaped metal strip includes a left oblique line, a middle horizontal line, and a right oblique line; two of the hook-shaped stripline resonators are bridged and integrated into the three substrate integrated waveguide resonators arranged in the product shape, one of the substrate integrated waveguide resonators is simultaneously coupled with the left oblique lines and horizontal lines of the two hook-shaped stripline resonators, and the right oblique lines of the two hook-shaped stripline resonators are separately coupled with the other two substrate integrated waveguide resonators; a coplanar waveguide transmission line is provided on each substrate integrated waveguide resonator, and the three coplanar waveguide transmission lines are arranged in the product shape.

2. The substrate integrated waveguide filter power divider according to claim 1, characterized in that: The hook-shaped metal strip is arranged in the middle layer of the device, and its two ends are respectively connected to the upper and lower metal layers through a metallized blind hole; the total length of the hook-shaped metal strip is between 0.29λ0 and 0.37λ0, the length of the left oblique line is between 0.09λ0 and 0.11λ0, the length of the right oblique line is between 0.16λ0 and 0.19λ0, the length of the middle horizontal line part is between 0.04λ0 and 0.07λ0, the spacing between the horizontal lines of the two hook-shaped metal strips is between 0.01λ0 and 0.02λ0, and λ0 is the air wavelength corresponding to the center frequency.

3. The substrate integrated waveguide filter power divider according to claim 2, characterized in that: The two ends of the resistor located on the upper layer of the device are respectively connected to a small metal patch, and then connected to the horizontal line parts of the two hook-shaped metal strips through metallized blind holes 2. The distance between the blind hole connection point and the right end of the horizontal line part of the hook-shaped metal strip is between 0.01λ0 and 0.02λ0.

4. The substrate integrated waveguide filter power divider according to claim 2 or 3, characterized in that: The three substrate integrated waveguide resonators arranged in a pattern are composed of the upper and lower metal ground layers, the dielectric layer and the metallized through-hole wall; the coplanar waveguide transmission line includes a pair of back-to-back symmetrical L-shaped grooves arranged on the upper metal ground layer, and metal strips are formed between the L-shaped grooves. The horizontal length of the L-shaped groove is between 0.11λ0 and 0.17λ0, and the vertical length is between 0.05λ0 and 0.07λ0.

5. The substrate integrated waveguide filter power divider according to any one of claims 1 to 3, characterized in that: The bandwidth is adjusted by adjusting the bending degree of the hook-shaped stripline resonator.

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