A broadband tunable planar filtering power divider

Abstract

The present application relates to a kind of broadband tunable planar filter power divider, belong to radio frequency and microwave device field.The device includes microstrip line structure, dielectric substrate and metal ground.Microstrip line structure and metal ground are respectively arranged on the two surfaces of dielectric substrate.Microstrip line structure includes first port, second port, third port, first branch microstrip line structure and second branch microstrip line structure, wherein first port is connected with first branch microstrip line structure and second branch microstrip line structure respectively;Second port is connected with first branch microstrip line structure;Third port is connected with second branch microstrip line structure.The planar filter power divider also includes parallel circuit structure, and the parallel circuit structure is connected with microstrip line structure.The present application has the advantages such as low cost, wide applicability, low power loss, etc., and the present application has relatively wide frequency tuning bandwidth.

Description

Technical Field

[0001] This invention belongs to the field of radio frequency and microwave devices, and relates to a wideband tunable planar filter power divider. Background Technology

[0002] In recent years, research in radio frequency (RF) and microwave technology has rapidly progressed towards integration and multifunctionality, with researchers increasingly emphasizing multifunctional integrated components or circuits. Filters and power dividers are two core passive microwave devices. Power dividers, which distribute and synthesize signals, are used in many antenna arrays and balanced circuits, making them a fundamental microwave circuit. Bandpass filters, on the other hand, isolate the desired frequency band and are another indispensable component in wireless communication systems. Integrating these two components not only reduces power loss in RF components but also decreases the overall device size. Currently, many designs have achieved excellent performance in power dividers, including low loss, high frequency selectivity, wide stopband rejection, and wideband isolation. However, there are currently no designs specifically for frequency-tunable power dividers. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a wideband tunable planar filter power divider that, by integrating the power divider and the filter in a design, enables the center frequency of the device to be flexibly tuned over a wide range and achieve high performance.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A wideband tunable planar filter power divider includes a microstrip line structure, a dielectric substrate, and a metal ground; wherein the microstrip line structure and the metal ground are respectively disposed on two sides of the dielectric substrate.

[0006] The microstrip line structure includes a first port 1, a second port 2, a third port 3, a first branch microstrip line structure, and a second branch microstrip line structure.

[0007] The first port 1 is connected to the first branch microstrip line structure and the second branch microstrip line structure respectively; the second port 2 is connected to the first branch microstrip line structure; and the third port 3 is connected to the second branch microstrip line structure.

[0008] The planar filter power divider also includes a parallel circuit structure connected to the microstrip line structure.

[0009] Optionally, the first branch microstrip line structure includes a first step impedance resonator I, a first open stub line I 403, a fourth microstrip line I 404, a first coupling line I 405, a second step impedance resonator I, a third step impedance resonator I, a tenth microstrip line I 410, a second coupling line I 411, and a twelfth microstrip line I 412.

[0010] The first step-impedance resonator I, the first open-circuit stub line I403, the fourth microstrip line I404, the first coupling line I405, the tenth microstrip line I410, the second coupling line I411, and the twelfth microstrip line I412 are connected in sequence. The second step-impedance resonator I and the third step-impedance resonator I are both connected to the connection point of the first coupling line I405 and the tenth microstrip line I410.

[0011] The first step impedance resonator I is connected to the first port 1; the twelfth microstrip line I 412 is connected to the second port 2; and the first coupling line I 405 is connected to the parallel circuit structure.

[0012] Optionally, the first step impedance resonator I includes a first microstrip line I 401 and a second microstrip line I 402. One end of the first microstrip line I 401 is connected to the first port 1, and the other end is connected to the second microstrip line I 402. The other end of the second microstrip line I 402 is connected to the first open stub line I 403. The first microstrip line I 401 is also connected to a parallel circuit structure.

[0013] The second step impedance resonator I includes a sixth microstrip line I406 and a seventh microstrip line I407; one end of the sixth microstrip line I406 is connected to the connection point of the first coupling line I405 and the tenth microstrip line I410, and the other end is connected to the seventh microstrip line I407, and the other end of the seventh microstrip line I407 is connected to a parallel circuit structure.

[0014] The third step impedance resonator I includes an eighth microstrip line I408 and a ninth microstrip line I409; one end of the eighth microstrip line I408 is connected to the connection point of the first coupling line I405 and the tenth microstrip line I410, and the other end is connected to the ninth microstrip line I409, and the other end of the ninth microstrip line I409 is connected to a parallel circuit structure.

[0015] Optionally, the second branch microstrip line structure includes a first step impedance resonator II, a first open stub line II 503, a fourth microstrip line II 504, a first coupling line II 505, a second step impedance resonator II, a third step impedance resonator II, a tenth microstrip line II 510, a second coupling line II 511, and a twelfth microstrip line II 512.

[0016] The first step impedance resonator II, the first open-circuit stub II 503, the fourth microstrip line II 504, the first coupling line II 505, the tenth microstrip line II 510, the second coupling line II 511, and the twelfth microstrip line II 512 are connected in sequence. The second step impedance resonator II and the third step impedance resonator II are both connected to the connection point of the first coupling line II 505 and the tenth microstrip line II 510.

[0017] The first step impedance resonator II is connected to the first port 1; the twelfth microstrip line II 512 is connected to the second port 2; and the first coupling line II 505 is connected to the parallel circuit structure.

[0018] Optionally, the first step impedance resonator II includes a first microstrip line II 501 and a second microstrip line II 502. One end of the first microstrip line II 501 is connected to the first port 1, and the other end is connected to the second microstrip line II 502. The other end of the second microstrip line II 502 is connected to the first open stub line II 503. The first microstrip line II 501 is also connected to a parallel circuit structure.

[0019] The second step impedance resonator II includes a sixth microstrip line II 506 and a seventh microstrip line II 507. One end of the sixth microstrip line II 506 is connected to the junction of the first coupling line II 505 and the tenth microstrip line II 510, and the other end is connected to the seventh microstrip line II 507. The other end of the seventh microstrip line II 507 is connected to a parallel circuit structure.

[0020] The third-step impedance resonator II includes an eighth microstrip line II 508 and a ninth microstrip line II 509. One end of the eighth microstrip line II 508 is connected to the junction of the first coupling line II 505 and the tenth microstrip line II 510, and the other end is connected to the ninth microstrip line II 509. The other end of the ninth microstrip line II 509 is connected to a parallel circuit structure.

[0021] Optionally, there are 8 parallel circuit structures, all of which are structurally identical. Each parallel circuit structure includes a capacitor, a resistor, a varactor diode, a first square microstrip line, a second square microstrip line, and a square microstrip line with metal vias. One end of the capacitor and resistor, as well as the negative terminal of the varactor diode, are connected to the first square microstrip line; the other end of the capacitor is connected to the microstrip line structure; the other end of the resistor is connected to an external voltage source via the second square microstrip line and a wire; the positive terminal of the varactor diode is connected to the square microstrip line with metal vias. The capacitors are surface-mount capacitors, and the resistors are surface-mount resistors.

[0022] Optionally, the first microstrip line I 401, the first microstrip line II 501, the second microstrip line I 402, the second microstrip line II 502, the tenth microstrip line I 410, the tenth microstrip line II 510, the twelfth microstrip line I 412, and the twelfth microstrip line II 512 are all bent structures.

[0023] Optionally, a first isolation resistor 6 and a second isolation resistor 7 are provided between the first branch microstrip line structure and the second branch microstrip line structure, and the first isolation resistor 6 and the second isolation resistor 7 are connected in parallel. Both isolation resistors are surface mount resistors.

[0024] Optionally, the first branch microstrip line structure and the second branch microstrip line structure are symmetrically arranged about the first port 1.

[0025] The beneficial effects of this invention are as follows: the center frequency is adjustable within the range of 1.6 GHz to 2.7 GHz, with a tuning bandwidth of 51.2%; simultaneously, the input return loss at each center point is better than 20 dB, the insertion loss is better than 2.9 dB (excluding 3 dB distribution loss), the output matching at each center point is better than 17 dB, and the isolation between output ports is better than 19 dB; a wide frequency tuning bandwidth is achieved, and the performance is excellent. Furthermore, by combining the filter and power divider on the same dielectric substrate, this invention has the advantages of low cost, wide applicability, and low power loss.

[0026] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0028] Figure 1 This is a schematic diagram of the planar structure of the power divider filter of the present invention;

[0029] Figure 2 This is a three-dimensional structural diagram of the power divider filter of the present invention;

[0030] Figure 3 This is a schematic diagram of the dimensions of the power divider filter of the present invention;

[0031] Figure 4 For the present invention S 11 S 21 and S 31 ADS simulation results;

[0032] Figure 5 For the present invention S 22 S 33 and S 23 ADS simulation results;

[0033] Figure 6For the present invention S 11 Comparison chart of measured and simulated parameter results;

[0034] Figure 7 For the present invention S 21 Comparison chart of measured and simulated parameter results;

[0035] Figure 8 For the present invention S 22 Comparison chart of measured and simulated parameter results;

[0036] Figure 9 For the present invention S 23 Comparison chart of measured and simulated parameter results.

[0037] Reference numerals: 1-First port; 2-Second port; 3-Third port; 6-First isolation resistor; 7-Second isolation resistor;

[0038] 401 - First microstrip line I; 402 - Second microstrip line I; 403 - First open-circuit stub line I; 404 - Fourth microstrip line I; 405 - First coupling line I; 406 - Sixth microstrip line I; 407 - Seventh microstrip line I; 408 - Eighth microstrip line I; 409 - Ninth microstrip line I; 410 - Tenth microstrip line I; 411 - Second coupling line I; 412 - Twelfth microstrip line I;

[0039] 501 - First microstrip line II; 502 - Second microstrip line II; 503 - First open-circuit stub line II; 504 - Fourth microstrip line II; 505 - First coupling line II; 506 - Sixth microstrip line II; 507 - Seventh microstrip line II; 508 - Eighth microstrip line II; 509 - Ninth microstrip line II; 510 - Tenth microstrip line II; 511 - Second coupling line II; 512 - Twelfth microstrip line II. Detailed Implementation

[0040] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0041] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0042] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0043] like Figures 1-3 The diagram shows a wideband tunable planar filter power divider. This planar filter power divider includes an upper microstrip line structure, isolation resistors, and parallel circuit structure; a middle dielectric substrate; and a bottom metal ground plane. The dielectric substrate is made of Rogers 4350B material with a relative permittivity of 3.66 and a thickness of [missing information]. The loss tangent is 0.0037°; the thickness of the metal ground is 0.035°. mm The overall structural dimensions of this planar filter power divider are: .

[0044] The upper-layer microstrip line structure includes a first port 1, a second port 2, a third port 3, a first branch microstrip line structure, and a second branch microstrip line structure. The first port 1 is connected to both the first and second branch microstrip line structures. The first branch microstrip line structure is then connected to the second port 2, and the second branch microstrip line structure is then connected to the third port 3. All three ports use 50-ohm microstrip lines of the same size, with a length of [missing information]. , width is .

[0045] Combination Figure 3 The structural dimensions of this invention are described in detail below:

[0046] Both the first microstrip line I401 and the first microstrip line II501 have bent structures and the same dimensions, respectively. , , The second microstrip line I402 and the second microstrip line II502 are both bent structures and have the same dimensions, respectively. , ,radius The central angle subtended is 90°. The dimensions of the first open-circuit stub I 403 and the first open-circuit stub II 503 are the same, respectively... , The fourth microstrip line I 404 and the fourth microstrip line II 504 have the same dimensions, respectively. , The first coupling line I405 and the first coupling line II505 have the same dimensions, respectively. , The distance between the two lines is The sixth microstrip line I 406, the sixth microstrip line II 506, the eighth microstrip line I 408, and the eighth microstrip line II 508 have symmetrical structures and the same dimensions, respectively. , The seventh microstrip line I 407 and the seventh microstrip line II 507 have the same dimensions, respectively. , The ninth microstrip line I409 and the ninth microstrip line II509 have the same dimensions, respectively. , The tenth microstrip line I410 and the tenth microstrip line II510 have the same dimensions and a radius of [missing information]. The central angle subtended by the circle is 90°. The dimensions of the second coupling line I 411 and the second coupling line II 511 are the same, respectively... , The distance between the two lines is The twelfth microstrip line I412 and the twelfth microstrip line II512 have the same dimensions and a radius of [missing information]. The central angle subtended by the circle is 90°.

[0047] In the parallel circuit structure, the square microstrip line dimension is 1.5. mm The varactor diodes are all selected from SkyworksSolutions Inc. models, namely... D 1(SMV2019-079LF) D 2(SMV2022-004LF), D 3(SMV2022-004LF) and D 4 (SMV2019-079LF); Capacitor C b Value is 20pF; resistance R b The value is 100kΩ; the resistance values ​​of the first isolation resistor 6 and the second isolation resistor 7 in the circuit are 70Ω and 50Ω respectively; the models of all surface mount capacitors and surface mount resistors are C0805 and R0805 respectively.

[0048] Figure 4 The figure shown is S of the present invention. 11 S 21 and S 31 The ADS simulation results for the parameters, as shown in the figure, indicate that the center frequency of the power divider can be adjusted between 1.6 GHz and 2.7 GHz, which is consistent with the layout simulation results when the capacitor is applied. Furthermore, the input return loss at the center point is better than 20 dB, and the insertion loss S corresponding to the center point is... 21 or S 31 All are better than 1.5dB (excluding 3dB distribution loss).

[0049] Figure 5 The figure shown is S of the present invention. 22 S 33 and S 23 The ADS simulation results for the parameters, as shown in the figure, indicate that after connecting the isolation resistor to the power divider filter, the output matching S at the center frequency between 1.6 GHz and 1.7 GHz is... 22 or S 33 It is better than 15dB, with output matching better than 20dB from 1.8GHz to 2.7GHz, and output port isolation S from 1.6GHz to 2.7GHz. 23 All are better than 10dB.

[0050] Figure 6 and Figure 7 For the planar filter power divider S 11 and S 21 The comparison chart of simulation and measured results shows that the center frequency of the tunable planar filter power divider can be arbitrarily adjusted between 1.6 GHz and 2.7 GHz, with a tuning bandwidth of 51.2%, and the input return loss S at the center point is... 11 All are better than 20dB, insertion loss S 21 All are better than 2.9dB (excluding 3dB distribution loss).

[0051] Figure 8 and Figure 9 For the planar filter power divider S 22 and S 23 The comparison chart of simulation and measured results of the parameters shows that the output at the center point matches S. 22 All are better than 17dB, and the isolation between ports S 23 The measured results are 19 dB better than the simulation results in the range of 1 GHz to 3.5 GHz, and the measured results are in good agreement with the simulation results.

[0052] Table 1 shows the voltage parameters at various center-point frequencies of the power divider layout with varactor diodes in ADS simulation:

[0053] Table 1

[0054]

[0055] Table 2 shows the measured voltage parameters corresponding to the center point frequencies of the frequency-tunable filter power divider:

[0056] Table 2

[0057]

[0058] The comparison between the two tables shows that the measured voltage values ​​at each center point frequency differ from the simulated voltage values ​​in ADS by less than 2V.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A wideband tunable planar filtering power divider, characterized by: The microstrip line structure, a dielectric substrate and a metal ground are included; the microstrip line structure and the metal ground are respectively arranged on two surfaces of the dielectric substrate; The microstrip line structure includes a first port (1), a second port (2), a third port (3), a first branch microstrip line structure and a second branch microstrip line structure; The first port (1) is connected with the first branch microstrip line structure and the second branch microstrip line structure respectively; the second port (2) is connected with the first branch microstrip line structure; and the third port (3) is connected with the second branch microstrip line structure; The planar filter power divider further includes a parallel circuit structure connected with the microstrip line structure; The first branch microstrip line structure includes a first step impedance resonator I, a first open stub line I (403), a fourth microstrip line I (404), a first coupling line I (405), a second step impedance resonator I, a third step impedance resonator I, a tenth microstrip line I (410), a second coupling line I (411) and a twelfth microstrip line I (412); The first step impedance resonator I, the first open stub line I (403), the fourth microstrip line I (404), the first coupling line I (405), the tenth microstrip line I (410), the second coupling line I (411) and the twelfth microstrip line I (412) are connected in sequence; the second step impedance resonator I and the third step impedance resonator I are both connected to the connection point of the first coupling line I (405) and the tenth microstrip line I (410); The first step impedance resonator I is connected with the first port (1); and the twelfth microstrip line I (412) is connected with the second port (2); The first coupling line I (405) is connected with the parallel circuit structure; The first step impedance resonator I includes a first microstrip line I (401) and a second microstrip line I (402); One end of the first microstrip line I (401) is connected with the first port (1), and the other end is connected with the second microstrip line I (402); the other end of the second microstrip line I (402) is connected with the first open stub line I (403); The first microstrip line I (401) is further connected with the parallel circuit structure; The second step impedance resonator I includes a sixth microstrip line I (406) and a seventh microstrip line I (407); one end of the sixth microstrip line I (406) is connected to the connection point of the first coupling line I (405) and the tenth microstrip line I (410), and the other end is connected with the seventh microstrip line I (407); the other end of the seventh microstrip line I (407) is connected with the parallel circuit structure; The third step impedance resonator I includes an eighth microstrip line I (408) and a ninth microstrip line I (409); one end of the eighth microstrip line I (408) is connected to the connection point of the first coupling line I (405) and the tenth microstrip line I (410), and the other end is connected with the ninth microstrip line I (409); the other end of the ninth microstrip line I (409) is connected with the parallel circuit structure; The second branch microstrip line structure comprises a first stepped impedance resonator II, a first open stub line II (503), a fourth microstrip line II (504), a first coupling line II (505), a second stepped impedance resonator II, a third stepped impedance resonator II, a tenth microstrip line II (510), a second coupling line II (511), and a twelfth microstrip line II (512); The first stepped impedance resonator II, the first open stub line II (503), the fourth microstrip line II (504), the first coupling line II (505), the tenth microstrip line II (510), the second coupling line II (511), and the twelfth microstrip line II (512) are sequentially connected; the second stepped impedance resonator II and the third stepped impedance resonator II are both connected to the connection point of the first coupling line II (505) and the tenth microstrip line II (510); The first stepped impedance resonator II is connected with the first port (1); the twelfth microstrip line II (512) is connected with the second port (2); The first coupling line II (505) is connected with the parallel circuit structure; The first stepped impedance resonator II comprises a first microstrip line II (501) and a second microstrip line II (502); one end of the first microstrip line II (501) is connected with the first port (1), and the other end is connected with the second microstrip line II (502); the other end of the second microstrip line II (502) is connected with the first open stub line II (503); the first microstrip line II (501) is also connected with the parallel circuit structure; The second stepped impedance resonator II comprises a sixth microstrip line II (506) and a seventh microstrip line II (507); one end of the sixth microstrip line II (506) is connected to the connection point of the first coupling line II (505) and the tenth microstrip line II (510), and the other end is connected with the seventh microstrip line II (507); the other end of the seventh microstrip line II (507) is connected with the parallel circuit structure; The third stepped impedance resonator II comprises an eighth microstrip line II (508) and a ninth microstrip line II (509); one end of the eighth microstrip line II (508) is connected to the connection point of the first coupling line II (505) and the tenth microstrip line II (510), and the other end is connected with the ninth microstrip line II (509); the other end of the ninth microstrip line II (509) is connected with the parallel circuit structure; The parallel circuit structure has 8 groups, and the 8 groups of parallel circuit structures are consistent in structure; The parallel circuit structure comprises a capacitor, a resistor, a varactor diode, a first square microstrip line, a second square microstrip line, and a metal via square microstrip line; one end of the capacitor and the resistor and the negative electrode of the varactor diode are all connected with the first square microstrip line; the other end of the capacitor is connected with the microstrip line structure; the other end of the resistor is connected with an external voltage source through the second square microstrip line and a wire; the positive electrode of the varactor diode is connected with the metal via square microstrip line.

2. The planar filter power divider of any one of claims 1, wherein: The first microstrip line I (401), the first microstrip line II (501), the second microstrip line I (402), the second microstrip line II (502), the tenth microstrip line I (410), the tenth microstrip line II (510), the twelfth microstrip line I (412) and the twelfth microstrip line II (512) are all bending structures.

3. The planar filtering power divider of claim 1, wherein: The first branch microstrip line structure and the second branch microstrip line structure are provided with a first isolation resistor (6) and a second isolation resistor (7) in parallel.

4. The planar filtering power divider of claim 1, wherein: The first branch microstrip line structure and the second branch microstrip line structure are symmetrically arranged about the first port (1).

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