A one-to-many-way substrate integrated waveguide broadband filter power divider

Abstract

The invention discloses a one-to-many-way substrate integrated waveguide broadband filtering power divider. A plurality of circularly symmetrically distributed three-terminal short-circuited T-type stripline resonators are respectively connected correspondingly to a central circular substrate integrated waveguide resonator and a peripheral fan-shaped substrate integrated waveguide resonator. The field distribution characteristics of the three-terminal short-circuited T-type stripline resonator are utilized to adjust the coupling between the resonators on each channel and the isolation between the T-type stripline resonators, thereby realizing a one-to-many-way substrate integrated waveguide broadband filtering power divider. The device has a multi-channel output capability and broadband working characteristics, and can take into account the fusion degree of filtering and power division, the order of filtering response, the consistency of output channel response, the stopband bandwidth and 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 key components of wireless communication systems, responsible for frequency selection and power distribution, respectively. Combining the filtering function and the power division function to form a filter power divider, that is, realizing two functions in a single device, can reduce the number of components, volume and structural complexity of the system, and improve the system integration. On the basis of the fusion of filtering and power division, the substrate integrated waveguide filter power divider can effectively utilize the high quality factor and low loss characteristics of the substrate integrated waveguide to further improve the performance of the filter power divider, but its working bandwidth is relatively limited, requiring relative bandwidth widening technology. At the same time, facing scenarios such as multi-channel power distribution and multi-port feeding networks, it is necessary to realize a one-to-many-channel substrate integrated waveguide filter power divider. Therefore, the substrate integrated waveguide filter power divider that can achieve one-to-many-channel and broadband operation has important engineering and application value.

[0003] There are three existing methods for realizing a one-to-many-way substrate integrated waveguide broadband filter power divider. The first is to couple the upper three-line coupled microstrip output result through a coupling slot on the basis of a second-order substrate integrated waveguide filter to realize a one-to-three-way power divider with a second-order filtering response, but there are problems such as narrow bandwidth, small number of power division paths, low fusion of filtering and power division, and poor consistency of output channels. The second is to feed the probe to a circular substrate integrated waveguide resonator, and then couple it to four one-eighth mode substrate integrated waveguide resonators on the upper layer through four slots to realize a one-to-four-way power divider with a second-order filtering response, which improves the fusion of filtering and power division and the consistency of the output channel, but there are problems such as narrow bandwidth, low filtering response order, small number of power division paths and large loss. The third is to output four ports on the upper and lower layers of a double-layer circular substrate integrated waveguide resonator loaded with multiple slots, forming a one-to-eight-way substrate integrated waveguide filter power divider, which has improved bandwidth and the number of power division paths, but there are problems such as poor output port isolation, narrow stopband, and poor output channel consistency. Therefore, it is necessary to propose a substrate integrated waveguide filter power divider, which not only has more channel output capabilities and broadband working characteristics, but also can take into account the integration of filtering and power division, filter response order, output isolation, output channel response consistency, stopband bandwidth and insertion loss. Summary of the invention

[0004] Purpose of the invention: In view of the above-mentioned prior art, a one-to-many-channel substrate integrated waveguide broadband filter power divider is proposed to simultaneously increase the number of power division channels and the working bandwidth, and improve the fusion degree of filtering and power division, the order of filtering response, output isolation, output channel response consistency, stopband width and loss.

[0005] Technical solution: A one-to-many-way substrate integrated waveguide broadband filter power divider comprises: a circular substrate integrated waveguide resonator, a plurality of fan-shaped substrate integrated waveguide resonators, and a plurality of three-terminal short-circuited T-type stripline resonators; the plurality of fan-shaped substrate integrated waveguide resonators are distributed around the periphery of the circular substrate integrated waveguide resonator to form a circular structure as a whole; the three-terminal short-circuited T-type stripline resonators are respectively and one-to-one connected across the central circular substrate integrated waveguide resonator and the peripheral fan-shaped substrate integrated waveguide resonators; the transmission signal is fed to the circular substrate integrated waveguide resonator through a coaxial probe, and is equally coupled to the fan-shaped substrate integrated waveguide resonators through the three-terminal short-circuited T-type stripline resonators, and is output from the coplanar waveguide transmission line at the outer edge of each fan-shaped substrate integrated waveguide resonator to achieve one-to-many-way.

[0006] Furthermore, the T-shaped top structure of the three-terminal short-circuited T-shaped stripline resonator is located in the circular substrate integrated waveguide resonator, and the coupling amount between the three-terminal short-circuited T-shaped stripline resonator and the circular substrate integrated waveguide resonator is adjusted by adjusting the length ratio of the T-shaped top structure in the stripline resonator.

[0007] Furthermore, the substrate integrated waveguide broadband filter power divider comprises a top circular metal ground, a first dielectric layer, an intermediate metal layer, a second dielectric layer, and a bottom circular metal ground which are stacked in sequence; wherein the intermediate metal layer is composed of a plurality of T-shaped metal strips;

[0008] It also includes a metallized through hole connecting the top circular metal ground and the bottom circular metal ground; the metallized through hole is composed of an outer ring metallized through hole, an inner ring metallized through hole and a plurality of radial metallized through holes; the outer ring metallized through hole and the inner ring metallized through hole are both provided with a plurality of circularly symmetrically distributed non-porous areas, and the center connecting line of the non-porous areas of the inner ring and the outer ring corresponding to each other points to the center of the circle of the overall structure; a plurality of radial metallized through holes divide the area between the outer ring metallized through hole and the inner ring metallized through hole into a plurality of fan-shaped structures; the top structure of each T-shaped metal strip is located in the inner ring metallized through hole, and the middle vertical line of the T-shaped metal strip penetrates into the fan-shaped structure from the center of the non-porous area of ​​the inner ring metallized through hole; the metallized blind hole connects the three end points of each T-shaped metal strip with the bottom circular metal ground;

[0009] Each T-shaped metal strip, the metallized blind hole, the top circular metal ground, the bottom circular metal ground, the first dielectric layer and the second dielectric layer constitute the three-terminal short-circuited T-shaped stripline resonator; the top circular metal ground, the first dielectric layer, the second dielectric layer, the bottom circular metal ground and the inner circle metallized through hole constitute the circular substrate integrated waveguide resonator; the outer circle metallized through hole, the inner circle metallized through hole, the radial metallized through hole, the top circular metal ground, the first dielectric layer, the second dielectric layer and the bottom circular metal ground constitute the several fan-shaped substrate integrated waveguide resonators.

[0010] Furthermore, the top circular metal ground has a pair of L-shaped grooves on the fan-shaped structure part, and a top metal strip is formed between the vertical parts of the two L-shaped grooves; the top metal strip, the first dielectric layer, the second dielectric layer and the bottom circular metal ground constitute the coplanar waveguide transmission line.

[0011] Furthermore, the length of the top metal strip is between 0.16λ0 and 0.19λ0, and the length of the horizontal portion of each L-shaped groove is between 0.05λ0 and 0.08λ0.

[0012] Beneficial effects: Most of the existing one-to-many-way substrate integrated waveguide filter power dividers have problems such as insufficient number of channels and limited bandwidth, and also have multiple problems such as low fusion degree of filtering and power division, low filter response order, poor output isolation, poor output channel response consistency, narrow stopband and large loss. The present invention uses a plurality of circularly symmetrically distributed three-terminal short-circuited T-type stripline resonators to respectively cross the central circular substrate integrated waveguide resonator and the peripheral fan-shaped substrate integrated waveguide resonator, and utilizes the field distribution characteristics of the three-terminal short-circuited T-type stripline resonator to adjust the coupling between the resonators on each channel and the isolation between the T-type stripline resonators, so as to realize a one-to-many-way substrate integrated waveguide broadband filter power divider, which has multi-channel output capability and broadband working characteristics, and can take into account the fusion degree of filtering and power division, the order of filter response, the consistency of output channel response, the stopband bandwidth and loss.

[0013] Specifically, the three-terminal short-circuited T-type stripline resonator is composed of a T-type stripline and metalized blind holes at three ends. Multiple T-type stripline resonators are distributed in a circular symmetrical manner. The T-type top structure is located in the circular substrate integrated waveguide resonator, and the vertical line bridges the peripheral fan-shaped substrate integrated waveguide resonator and the central circular substrate integrated waveguide resonator. The electric field distribution of the three-terminal short-circuited T-type stripline resonator shows a distribution characteristic of weak at the three ends and strong in the middle, and the current on both sides of the strip of the top horizontal part is distributed in reverse, which can provide a resonance point for each output channel, control the coupling coefficient and form a wide stopband.

[0014] The circular substrate integrated waveguide resonator is composed of an inner circle of metallized through holes with multiple hole-free areas and upper and lower metal grounds, and works in TM 110mode, which can couple with the circularly symmetrically distributed three-terminal short-circuited T-type stripline resonator to form equal-amount in-phase coupling, is the basis for forming one-to-many equal power division and provides a resonance point for each output channel.

[0015] The fan-shaped substrate integrated waveguide resonator is surrounded by inner and outer metallized through holes and upper and lower metal grounds, and works in TM 110 mode, which can couple with the three-terminal short-circuited T-type stripline resonator and provide a resonance point for each output channel; at the same time, the hole-free area between the fan-shaped substrate integrated waveguide resonator and the circular substrate integrated waveguide resonator provides weak coupling between the two as cross-coupling of each output channel, introducing a transmission zero point in the upper stopband to improve the stopband performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a layer structure diagram of the one-to-eight-way substrate integrated waveguide broadband filtering power divider of the present invention;

[0017] Figure 2 This is a top metal structure diagram of the one-to-eight-way substrate integrated waveguide broadband filter power divider of the present invention;

[0018] Figure 3 This is a diagram of the metal structure of the middle layer of the one-to-eight-way substrate integrated waveguide broadband filter power divider of the present invention;

[0019] Figure 4 This is a bottom metal structure diagram of the one-to-eight-way substrate integrated waveguide broadband filter power divider of the present invention;

[0020] Figure 5 The simulation matching and power division curve of the one-to-eight-way substrate integrated waveguide broadband filter power divider of the present invention;

[0021] Figure 6 This is a simulated isolation curve of the one-to-eight-way substrate integrated waveguide broadband filtering power divider of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further explained below in conjunction with the accompanying drawings.

[0023] like Figure 1 As shown, a one-to-eight-way substrate integrated waveguide broadband filtering power divider includes a top metal layer 1, a first dielectric layer 2, an intermediate metal layer 3, a second dielectric layer 4, and a bottom metal layer 5 stacked in sequence, and also includes a metallized through hole 6, a metallized blind hole 7 and a coaxial probe 8.

[0024] like Figure 2As shown, the top metal layer 1 is a top circular metal ground 102 with eight pairs of L-shaped grooves 101. The eight pairs of L-shaped grooves 101 are distributed on the edge of the top circular metal ground 102 in a circular array about the center of the top circular metal ground 102, that is, the eight pairs of L-shaped grooves 101 are symmetrically distributed about the center of the circle, and the circumferential spacing is the same. A top metal strip 103 is formed between the vertical parts of each pair of L-shaped grooves 101, and the top metal strip 103 is located on the axis of the circle. The length of the top metal strip 103 is 0.16λ0~0.19λ0, λ0 is the air wavelength corresponding to the center frequency, and the length of the horizontal part of each L-shaped groove 101 is 0.05λ0~0.08λ0.

[0025] The middle metal layer 3 is composed of eight T-shaped metal strips 301, which are distributed in a circular array, and the T-shaped top structure is located inside the ring and faces the center of the circle. The total length of each T-shaped metal strip 301 is 0.42λ0~0.55λ0, and the length of the vertical line in the middle of the T-shaped metal strip 301 is 0.28λ0~0.31λ0.

[0026] The bottom metal layer 5 is a bottom circular metal ground 502 with a circular groove 501 in the center. The radius of the circular groove 501 is between 0.03λ0 and 0.04λ0.

[0027] The metallized through hole 6 is used to connect the top metal layer 1 and the bottom metal layer 5, and is composed of an outer ring metallized through hole 601, an inner ring metallized through hole 602 and eight radial metallized through holes 603. Among them, the outer ring metallized through hole 601 and the inner ring metallized through hole 602 both have eight circularly symmetrically distributed non-porous areas, and the center line connecting the inner and outer ring non-porous areas points to the center of the overall structure, that is, the connecting line is located on the axis of the circle. The top structure of each T-shaped metal strip 301 is located in the inner ring metallized through hole 602, and the middle vertical line of the T-shaped metal strip 301 passes through the center of the non-porous area of ​​the inner ring metallized through hole 602 to the outside of the inner ring metallized through hole 602. The metallized blind hole 701 is used to connect the three end points of the T-shaped metal strip 301 with the bottom metal layer 5. The coaxial probe 8 passes through the center of the annular groove 501 through the probe inner core 801 and is connected to the center of the top circular metal ground 102.

[0028] In the above structure, each T-shaped metal strip 301, the metalized blind hole 701, the top metal layer 1, the bottom metal layer 5, the first dielectric layer 2 and the second dielectric layer 4 form a three-terminal short-circuited T-shaped stripline resonator. The top metal layer 1, the first dielectric layer 2, the second dielectric layer 4, the bottom metal layer 5 and the inner circle metallized through hole 602 form a circular substrate integrated waveguide resonator. The outer circle metallized through hole 601, the inner circle metallized through hole 602 and the radial metallized through hole 603, the top metal layer 1, the first dielectric layer 2, the second dielectric layer 4 and the bottom metal layer 5 form eight fan-shaped substrate integrated waveguide resonators. The top metal strip 103, the first dielectric layer 2, the second dielectric layer 4 and the bottom circular metal ground 502 form the coplanar waveguide transmission line.

[0029] In the present invention, the transmission signal is fed from the bottom coaxial probe 8 to the circular substrate integrated waveguide resonator, passes through eight three-terminal short-circuited T-type stripline resonators and eight fan-shaped substrate integrated waveguide resonators, and is output from eight coplanar waveguide transmission lines. Under the action of the overall structure, a one-to-eight-way substrate integrated waveguide broadband filtering power divider is realized.

[0030] In this process, the electric field distribution of the three-terminal short-circuited T-type stripline resonator shows a distribution characteristic of weak at the three ends and strong in the middle, and the current on both sides of the strip at the top horizontal part is distributed in the opposite direction. 110 The eight three-terminal short-circuited T-type stripline resonators can obtain equal coupling from the circular substrate integrated waveguide resonator, and the coupling between the three-terminal short-circuited T-type stripline resonators is weak. The above characteristics provide a basis for eight-way equal power division and output isolation, and by adjusting the length ratio of the T-type top structure in the stripline resonator and its bending, the coupling amount between the stripline resonator and the circular substrate integrated waveguide resonator can be adjusted, thereby achieving the purpose of adjusting bandwidth and matching.

[0031] The vertical strips of eight three-terminal short-circuited T-type stripline resonators extend to eight TM 110 In the fan-shaped substrate integrated waveguide resonator of the mode, equal coupling between the two resonators is achieved, and the equal power division output characteristics are maintained. At the same time, on each output channel, there is a resonance point provided by the circular substrate integrated waveguide resonator, the three-terminal short-circuited T-type stripline resonator and the fan-shaped substrate integrated waveguide resonator, so a third-order filtering response can be obtained in each output channel.

[0032] Since the high-order mode resonant frequency distribution of the three-terminal short-circuited T-type stripline resonator is quite different from that of the substrate integrated waveguide resonator, the coupling between the high-order modes is weak, which is conducive to achieving a wider stopband bandwidth. In addition, the non-hole area between the circular substrate integrated waveguide resonator and the fan-shaped substrate integrated waveguide resonator provides a weak coupling between the two as the cross-coupling of each output channel, which can introduce a transmission zero in the upper stopband and improve the stopband performance.

[0033] Therefore, the present invention provides a one-to-many-channel substrate integrated waveguide broadband filter power divider, which has multi-channel output capability and broadband working characteristics, and can take into account the fusion degree of filtering and power division, the filter response order, the output channel response consistency, the stopband bandwidth and the loss.

[0034] This embodiment uses a Taconic TLY-5 substrate with two layers of the same thickness, and the circuit size is 1.71λ0×1.71λ0. Figure 5 , Figure 6 Given this embodiment S Parameter simulation curve, from the figure, it can be seen that the eight-way transmission response of the substrate integrated waveguide filter power divider completely overlaps, indicating that the eight-way output response has good consistency and is equal power division output. Figure 5 As shown in the figure, the corresponding 3-dB working bandwidth frequency range is 9.08 GHz - 10.66 GHz, that is, the relative bandwidth can reach 16.0%, the minimum insertion loss is only 0.69 dB, and the third-order filtering response is achieved. The three transmission poles are located at 9.39 GHz, 9.82 GHz and 10.37 GHz respectively. The transmission zero point outside the frequency band improves the stopband performance. The 20-dB stopband frequency range covers 10.97 GHz-19.34 GHz. Figure 6 As shown, the isolation between the output ports within the band is greater than 16.5 dB.

[0035] 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 one-to-many-way substrate integrated waveguide broadband filter power divider, characterized in that: include: A circular substrate integrated waveguide resonator, a plurality of fan-shaped substrate integrated waveguide resonators, and a plurality of three-terminal short-circuited T-type stripline resonators; the plurality of fan-shaped substrate integrated waveguide resonators are distributed around the periphery of the circular substrate integrated waveguide resonator, forming a circular structure as a whole; the three-terminal short-circuited T-type stripline resonators are respectively connected one by one across the central circular substrate integrated waveguide resonator and the peripheral fan-shaped substrate integrated waveguide resonators; the transmission signal is fed to the circular substrate integrated waveguide resonator through a coaxial probe , respectively coupled to each fan-shaped substrate integrated waveguide resonator in equal amounts through each three-terminal short-circuited T-type stripline resonator, and output from the coplanar waveguide transmission line at the outer edge of each fan-shaped substrate integrated waveguide resonator, so as to realize one-to-many paths; the T-shaped top structure of the three-terminal short-circuited T-type stripline resonator is located in the circular substrate integrated waveguide resonator, and the coupling amount between the three-terminal short-circuited T-type stripline resonator and the circular substrate integrated waveguide resonator is adjusted by adjusting the length ratio of the T-shaped top structure in the stripline resonator.

2. The one-to-many-channel substrate integrated waveguide broadband filter power divider according to claim 1, characterized in that: The substrate integrated waveguide broadband filter power divider comprises a top circular metal ground (102), a first dielectric layer (2), an intermediate metal layer (3), a second dielectric layer (4), and a bottom circular metal ground (502) which are stacked in sequence; wherein the intermediate metal layer (3) is composed of a plurality of T-shaped metal strips (301); It also includes a metallized through hole (6) connecting the top circular metal ground (102) and the bottom circular metal ground (502); the metallized through hole (6) is composed of an outer ring metallized through hole (601), an inner ring metallized through hole (602) and a plurality of radial metallized through holes (603); the outer ring metallized through hole (601) and the inner ring metallized through hole (602) are both provided with a plurality of circularly symmetrically distributed non-porous areas, and the center connecting line of the inner ring and the outer ring non-porous areas corresponding to each other points to the center of the overall structure; the plurality of radial metallized through holes (603) are connected to the outer ring metallized through hole (601) and the inner ring metallized through hole (602). The metallized through hole (603) divides the area between the outer ring metallized through hole (601) and the inner ring metallized through hole (602) into a plurality of fan-shaped structures; the top structure of each T-shaped metal strip (301) is located in the inner ring metallized through hole (602), and the middle vertical line of the T-shaped metal strip (301) penetrates into the fan-shaped structure from the center of the non-porous area of ​​the inner ring metallized through hole (602); the metallized blind hole (701) connects the three end points of each T-shaped metal strip (301) with the bottom circular metal ground (502); Each T-shaped metal strip (301) and the metallized blind hole (701), the top circular metal ground (102), the bottom circular metal ground (502), the first dielectric layer (2) and the second dielectric layer (4) form the three-terminal short-circuit T-shaped stripline resonator; the top circular metal ground (102), the first dielectric layer (2), the second dielectric layer (4), the bottom circular metal ground (502) and the inner circle metallized through hole (602) form the circular substrate integrated waveguide resonator; the outer circle metallized through hole (601), the inner circle metallized through hole (602), the radial metallized through hole (603), the top circular metal ground (102), the first dielectric layer (2), the second dielectric layer (4) and the bottom circular metal ground (502) form the plurality of fan-shaped substrate integrated waveguide resonators.

3. The one-to-many-channel substrate integrated waveguide broadband filtering power divider according to claim 2, characterized in that: The top circular metal ground (102) is provided with a pair of L-shaped grooves (101) on the fan-shaped structure part, and a top metal strip (103) is formed between the vertical parts of the two L-shaped grooves (101); the top metal strip (103), the first dielectric layer (2), the second dielectric layer (4) and the bottom circular metal ground (502) form the coplanar waveguide transmission line.

4. The one-to-many-channel substrate integrated waveguide broadband filter power divider according to claim 3, characterized in that: The length of the top metal strip (103) is between 0.16λ0 and 0.19λ0, and the length of the horizontal portion of each L-shaped slot (101) is between 0.05λ0 and 0.08λ0, where λ0 is the air wavelength corresponding to the center frequency.

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