A linear multi-zero-point cavity duplexer based on hybrid resonators

Abstract

This invention discloses a linear multi-zero cavity duplexer based on a hybrid resonator. The duplexer comprises a rectangular hollow metal cavity, a common signal terminal at the top of the cavity, and two signal branches on either side. The branches employ a hybrid cascaded structure of single-mode and dual-mode metal resonators, forming a linear topology without cross-coupling. The dual-mode metal resonator can operate simultaneously in inter-plate coupling mode and coaxial mode. The resonant mode order is set by pre-setting the internal inter-plate distance, allowing each branch to generate two preset transmission zeros. This invention achieves a six-pole filtering response using only four resonant cavities, forming a dual passband and generating four preset transmission zeros, ensuring high quality factor and high channel isolation while achieving device miniaturization. This invention features a simple structure, easy fabrication, and independently and precisely adjustable coupling parameters, making it suitable for 5G / 6G communication, emergency communication, and UAV-borne high-performance miniaturized RF front-end applications.

Description

Technical Field

[0001] This invention relates to a linear multi-zero cavity duplexer based on a hybrid resonator. Background Technology

[0002] With the rapid development of 5G / 6G communication, emergency communication, and other fields, the demand for miniaturization, high integration, and high selectivity in radio frequency (RF) front-end devices is becoming increasingly urgent. As a core component of the RF front-end, the cavity duplexer is responsible for isolating and separating signals across different frequency bands, and its performance directly determines the signal quality and battery life of the communication system.

[0003] Existing cavity duplexers mostly adopt cross-coupled topologies to introduce transmission zeros and improve out-of-band rejection. However, the cross-coupled structure leads to increased device size and manufacturing complexity, making it difficult to meet the stringent space constraints of UAVs and other applications. At the same time, duplexers composed of traditional single-mode resonators have a limited number of poles, insufficient out-of-band rejection capability, and poor flexibility in adjusting the position of transmission zeros, making them unsuitable for multi-band and wide-isolation communication requirements.

[0004] Furthermore, existing duplexers generally suffer from low integration and strong coupling in resonant frequency control: single-mode and dual-mode resonators interfere with each other, making it difficult to achieve independent frequency matching between the two channels; some structures rely on complex cross-coupling paths, further increasing device size and fabrication difficulty, making it impossible to simultaneously achieve the dual goals of miniaturization and high performance. Therefore, developing a cavity duplexer with a simple structure, high integration, and flexible controllable transmission zero point has become an urgent technical problem to be solved in the field of RF microwave devices. Summary of the Invention

[0005] The present invention provides a linear multi-zero cavity duplexer based on a hybrid resonator to solve the problems existing in the prior art.

[0006] The technical solutions adopted in this invention are as follows:

[0007] A linear multi-zero cavity duplexer based on a hybrid resonator includes:

[0008] Metal cavity;

[0009] A common signal terminal is located on the upper part of the metal cavity;

[0010] A first signal branch and a second signal branch are respectively disposed on both sides of the metal cavity. Both the first and second signal branch terminals are formed by a linear topology of cascaded single-mode and dual-mode metal resonators.

[0011] The first signal branch terminal includes a first single-mode metal resonator and a first dual-mode metal resonator cascaded in a straight line, and the second signal branch terminal includes a second single-mode metal resonator and a second dual-mode metal resonator cascaded in a straight line.

[0012] The first single-mode metal resonator and the second single-mode metal resonator are close to and coupled to the signal common terminal, while the first dual-mode metal resonator and the second dual-mode metal resonator are far from the signal common terminal.

[0013] Both the first signal branch and the second signal branch are straight-line cascaded structures without cross-coupling. The first dual-mode metal resonator and the second dual-mode metal resonator are configured to support two resonance modes: inter-metal plate coupling mode and coaxial mode. The resonant frequency order of the two modes is set by preset the distance between their internal metal plates, so that each corresponding signal branch generates two preset transmission zeros.

[0014] Furthermore, the metal cavity is a rectangular hollow cavity.

[0015] Furthermore, the signal common terminal includes a first SMA connector, the length of which is adjustable to simultaneously adjust the external coupling of the first signal branch terminal and the second signal branch terminal.

[0016] Furthermore, the first dual-mode metal resonator and the second dual-mode metal resonator are respectively connected to the second SMA connector and the third SMA connector, and the positions of the second SMA connector and the third SMA connector are adjustable to independently adjust the external coupling of the corresponding branch.

[0017] Furthermore, both the first single-mode metal resonator and the second single-mode metal resonator are rectangular concave metal resonant cavities and operate in coaxial mode, while both the first dual-mode metal resonator and the second dual-mode metal resonator are metal plate coupled resonant cavities and operate in inter-plate coupled mode and coaxial mode.

[0018] Furthermore, a first metal coupling window for adjusting external coupling is provided between the first single-mode metal resonator and the signal common terminal, and between the second single-mode metal resonator and the signal common terminal.

[0019] A second metal coupling window for adjusting internal coupling is provided between the first single-mode metal resonator and the first dual-mode metal resonator, and between the second single-mode metal resonator and the second dual-mode metal resonator.

[0020] Furthermore, the sizes of both the first and second metal coupling windows can be adjusted to control the corresponding coupling coefficients.

[0021] Furthermore, the first signal branch terminal and the second signal branch terminal are asymmetrically configured and operate at different center frequencies.

[0022] Furthermore, by presetting the distance between the internal metal plates of the first dual-mode metal resonator and the second dual-mode metal resonator, the resonant frequency order of the two modes is set. When the coaxial mode is the first resonant mode, both transmission zeros are located on the right side of the passband; when the metal plate coupling mode is the first resonant mode, the first transmission zero is located on the left side of the passband, and the second transmission zero is located on the right side of the passband.

[0023] Furthermore, the duplexer uses only two single-mode metal resonators and two dual-mode metal resonators to achieve a six-pole response, forming a dual passband and generating four preset transmission zeros.

[0024] The present invention has the following beneficial effects:

[0025] (1) Achieving extreme miniaturization and high-order performance indicators: Six poles can be generated using only four resonant cavities without the need for additional resonant cavities or auxiliary structures, which greatly reduces the size of the device.

[0026] (2) Flexible transmission zero control and high isolation: By utilizing the mode characteristics of the dual-mode resonator, multiple controllable transmission zeros can be introduced in a linear topology, which improves the out-of-band suppression capability and the isolation between channels.

[0027] (3) Maintaining a high quality factor (Q value): Since there is no need to introduce a complex cross-coupling structure, the internal physical design of the device is simplified, and signal transmission loss is effectively reduced.

[0028] (4) Independent and precise coupling adjustment: By setting the position of the SMA connector, the coupling window between signal terminals and the size of the coupling window between resonators, the decoupling control of internal coupling and external coupling is realized, reducing the difficulty of debugging. Attached Figure Description

[0029] Figure 1 This is a three-dimensional structural diagram of a linear multi-zero cavity duplexer based on a hybrid resonator in this embodiment.

[0030] Figure 2(a) is a top view of the linear multi-zero cavity duplexer based on a hybrid resonator in this embodiment.

[0031] Figure 2(b) is a top view of the linear multi-zero cavity duplexer based on a hybrid resonator in this embodiment.

[0032] Figure 3 The diagram shows the effect of the insertion length of the 3rd feed pin of the first SMA connector on external coupling.

[0033] Figure 4The diagram shows the effect of the size of the metal coupling window and the resonator spacing on the amount of external coupling.

[0034] Figure 5 This diagram illustrates the effect of the distance between the internal metal plates of a dual-mode metal resonator on the position of the transmission zero point.

[0035] Figure 6 This is a simulation diagram of the S-parameters of a linear multi-zero cavity duplexer based on a hybrid resonator in this embodiment. Detailed Implementation

[0036] The invention will now be further described with reference to the accompanying drawings.

[0037] like Figure 1 As shown in Figures 2(a) and 2(b), this embodiment discloses a linear multi-zero cavity duplexer based on a hybrid resonator. The overall structure employs a rectangular hollow metal cavity 2 with dimensions b=23mm, a=68mm, and H=24mm. The metal cavity thickness is 4mm, and the thickness of the metal coupling windows is t=1mm. The overall structure has a linear layout with no cross-coupling paths. In this embodiment, the given structural dimensions are preferred dimensions. Referring to this embodiment, modifying the dimensional parameters of each component can further obtain the performance required in practice.

[0038] The signal common terminal 14 is located at the middle position of the upper part of the metal cavity 2. The signal common terminal 14 is equipped with a first SMA connector 3, which is vertically inserted into the metal cavity 2, with its feed pin extending L. h = 14.7 mm, feed needle insertion length L h The external coupling strength between the first signal branch terminal 13 and the second signal branch terminal 15 can be adjusted according to usage requirements. For example... Figure 3 As shown, the insertion length L of the first SMA connector 3 feed pins is... h The longer the length, the lower the external quality factor and the stronger the external coupling effect.

[0039] The metal cavity 2 is provided with a first signal branch terminal 13 and a second signal branch terminal 15 on both sides. Both branches adopt a linear topology structure of hybrid cascaded single-mode metal resonators and dual-mode metal resonators, and the two branches are asymmetrically configured, so they can work at different center frequencies.

[0040] The first signal branch terminal 13 is formed by cascading the first single-mode metal resonator 5 and the first dual-mode metal resonator 7 in a straight line. The second signal branch terminal 15 is formed by cascading the second single-mode metal resonator 12 and the second dual-mode metal resonator 10 in a straight line. The first single-mode metal resonator 5 and the second single-mode metal resonator 12 are both located close to the signal common terminal 14 and are coupled to the signal common terminal 14. The first dual-mode metal resonator 7 and the second dual-mode metal resonator 10 are both located away from the signal common terminal 14.

[0041] Both the first single-mode metal resonator 5 and the second single-mode metal resonator 12 adopt a rectangular concave metal resonant cavity structure and operate only in coaxial mode. The height of the first single-mode metal resonator 5 is H1 = 14.03 mm, and the height of the second single-mode metal resonator 12 is H2 = 11.77 mm. The side curvature of the two single-mode metal resonators is consistent, C1 = 2.21 mm and C2 = 3.68 mm. The resonant frequency can be independently adjusted by adjusting their physical dimensions.

[0042] Both the first dual-mode metal resonator 7 and the second dual-mode metal resonator 10 adopt a metal plate coupled resonant cavity structure, which can simultaneously support two resonance modes: metal plate coupled mode and coaxial mode. The gap between the metal plates inside the first dual-mode metal resonator 7 is gap2 = 1.74 mm, and the gap between the metal plates inside the second dual-mode metal resonator 10 is gap = 1.1 mm. By preset the internal plate distance of the two dual-mode metal resonators, the frequency order of the two resonance modes can be set, thereby completing the preset of the transmission zero point position.

[0043] A first metal coupling window for adjusting external coupling is provided between the first single-mode metal resonator 5 and the signal common terminal 14, and between the second single-mode metal resonator 12 and the signal common terminal 14. The thickness of the first metal coupling window is t = 1 mm, and the width of the first metal coupling window connecting the first single-mode metal resonator 5 is W. c21 = 7.6 mm, height h c11 = 8.5mm, the width W of the first metal coupling window connecting the second single-mode metal resonator 12 c = 9.4 mm, height h c21 = 8 mm.

[0044] A second metal coupling window for adjusting internal coupling is provided between the first single-mode metal resonator 5 and the first dual-mode metal resonator 7, and between the second single-mode metal resonator 12 and the second dual-mode metal resonator 10. The thickness t of the second metal coupling window is also 1 mm, and the width W of the second metal coupling window connecting the first dual-mode metal resonator 7 is... c22 = 6.2 mm, height h c22= 9 mm, the width W of the second metal coupling window connecting the second dual-mode metal resonator 10 c12 = 10.4 mm, height is 9 mm, such as Figure 4 As shown, the sizes of the first metal coupling window and the second metal coupling window can be flexibly adjusted to precisely control the corresponding external coupling coefficient and internal coupling coefficient.

[0045] The distance S between the edge of the first single-mode metallic resonator 5 and the center of the first dual-mode metallic resonator 7 12 = 8.75mm, the center distance S between the first single-mode metal resonator 5 and the metal cavity 2 11 = 0.6mm, the center distance S between the second single-mode metal resonator 12 and the metal cavity 2 is 4.7mm, and the center distance S between the edge of the second single-mode metal resonator 12 and the center of the second dual-mode metal resonator 10 is S. 22 =8.47mm.

[0046] The first dual-mode metal resonator 7 is connected to the second SMA connector 4, and the second dual-mode metal resonator 10 is connected to the third SMA connector 1. The second SMA connector 4 and the third SMA connector 1 are centrally symmetrically arranged on both sides of the metal cavity 2. The position parameters are: t1 = 5.5 mm, t2 = 5.7 mm, Hp1 = 4.15 mm, Hp2 = 3.35 mm. The installation positions of the two output connectors can be adjusted independently to adjust the external coupling value of the corresponding signal branch terminals respectively.

[0047] Other physical parameters of the first dual-mode metal resonator 7 and the second dual-mode metal resonator 10: l 11 = 3.5 mm,l 12 = 6 mm, l 13 = 5.6 mm, l 14 = 9.09 mm, l 21 =3.5 mm, l 22 = 5.8 mm, l 23 = 5.67 mm,l 24 = 7.5 mm, w 11 = 4 mm, w 12 = 4.55 mm, w 13 = 4 mm, w 14 = 2.4 mm, w 21 = 4 mm, w 22 = 2.4 mm, w 23 = 4 mm, w 24 = 3.76 mm, θ1= 29°, θ2=28°, gap 11= 8.95 mm, gap 21 =6.2 mm.

[0048] like Figure 5 As shown, by presetting the distance between the internal metal plates of the first dual-mode metal resonator 7 and the second dual-mode metal resonator 10, the order of the two resonant modes can be determined. When the coaxial mode is the first resonant mode, the two transmission zeros at the corresponding signal branch end are both located on the right side of the passband. When the inter-metal plate coupling mode is the first resonant mode, the first transmission zero at the corresponding signal branch end is located on the left side of the passband, and the second transmission zero is fixedly located on the right side of the passband, thus realizing the on-demand preset of the transmission zero position.

[0049] In this embodiment, the duplexer uses only two single-mode metal resonators (first single-mode metal resonator 5 and second single-mode metal resonator 12) and two dual-mode metal resonators (first dual-mode metal resonator 7 and second dual-mode metal resonator 10), a total of four resonant cavities, to achieve a six-pole filtering response and form a dual-passband operating mode. Figure 6 As shown, the dual passband center frequencies are 3.32GHz and 3.98GHz, respectively, with a bandwidth of 150MHz. The first signal branch terminal 13 and the second signal branch terminal 15 each generate two preset transmission zeros, achieving a total of four controllable transmission zeros. The channel isolation can reach -30dB, maintaining a high quality factor without cross-coupling structure, effectively reducing signal transmission loss. At the same time, each coupling parameter can be adjusted independently, greatly reducing the difficulty of device debugging and adapting to the needs of miniaturized high-performance communication systems.

[0050] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. A linear multi-zero cavity duplexer based on a hybrid resonator, characterized in that: include: Metal cavity (2); The signal common terminal (14) is located on the upper part of the metal cavity (2); The first signal branch terminal (13) and the second signal branch terminal (15) are respectively arranged on both sides of the metal cavity (2). The first signal branch terminal (13) and the second signal branch terminal (15) are both formed by a linear topology of a hybrid cascade of single-mode metal resonators and dual-mode metal resonators; wherein, The first signal branch (13) includes a first single-mode metal resonator (5) and a first dual-mode metal resonator (7) cascaded in a straight line, and the second signal branch (15) includes a second single-mode metal resonator (12) and a second dual-mode metal resonator (10) cascaded in a straight line. The first single-mode metal resonator (5) and the second single-mode metal resonator (12) are close to the signal common terminal (14) and coupled to the signal common terminal (14), while the first dual-mode metal resonator (7) and the second dual-mode metal resonator (10) are far away from the signal common terminal (14). The first signal branch (13) and the second signal branch (15) are both straight-line cascaded structures without cross-coupling. The first dual-mode metal resonator (7) and the second dual-mode metal resonator (10) are both configured to support two resonance modes: inter-metal plate coupling mode and coaxial mode. The resonance frequency order of the two modes is set by preset the inter-metal plate distance, so that each corresponding signal branch generates two preset transmission zeros.

2. The linear multi-zero cavity duplexer based on a hybrid resonator as described in claim 1, characterized in that: The metal cavity (2) is a rectangular hollow cavity.

3. The linear multi-zero cavity duplexer based on a hybrid resonator as described in claim 1, characterized in that: The signal common terminal (14) includes a first SMA connector (3) whose feed pin extension length is adjustable to simultaneously adjust the external coupling of the first signal branch terminal (13) and the second signal branch terminal (15).

4. The linear multi-zero cavity duplexer based on a hybrid resonator as described in claim 1, characterized in that: The first dual-mode metal resonator (7) and the second dual-mode metal resonator (10) are respectively connected to the second SMA connector (4) and the third SMA connector (1). The positions of the second SMA connector (4) and the third SMA connector (1) are adjustable to independently adjust the external coupling of the corresponding branch.

5. The linear multi-zero cavity duplexer based on a hybrid resonator as described in claim 1, characterized in that: The first single-mode metal resonator (5) and the second single-mode metal resonator (12) are both rectangular concave metal resonator cavities and operate in coaxial mode. The first dual-mode metal resonator (7) and the second dual-mode metal resonator (10) are both metal plate coupled resonator cavities and operate in metal plate coupled mode and coaxial mode.

6. The linear multi-zero cavity duplexer based on a hybrid resonator as described in claim 1, characterized in that: A first metal coupling window for adjusting external coupling is provided between the first single-mode metal resonator (5) and the signal common terminal (14) and between the second single-mode metal resonator (12) and the signal common terminal (14); A second metal coupling window for adjusting internal coupling is provided between the first single-mode metal resonator (5) and the first dual-mode metal resonator (7) and between the second single-mode metal resonator (12) and the second dual-mode metal resonator (10).

7. The linear multi-zero cavity duplexer based on a hybrid resonator as described in claim 6, characterized in that: The sizes of both the first and second metal coupling windows can be adjusted to control the corresponding coupling coefficients.

8. The linear multi-zero cavity duplexer based on a hybrid resonator as described in claim 1, characterized in that: The first signal branch terminal (13) and the second signal branch terminal (15) are asymmetrically configured and operate at different center frequencies.

9. The linear multi-zero cavity duplexer based on a hybrid resonator as described in claim 1, characterized in that: The resonant frequency order of the two modes is set by presetting the distance between the internal metal plates of the first dual-mode metal resonator (7) and the second dual-mode metal resonator (10). When the coaxial mode is the first resonant mode, both transmission zeros are located on the right side of the passband. When the metal plate coupling mode is the first resonant mode, the first transmission zero is located on the left side of the passband and the second transmission zero is located on the right side of the passband.

10. The linear multi-zero cavity duplexer based on a hybrid resonator as described in claim 1, characterized in that: The duplexer uses only two single-mode and two dual-mode metal resonators to achieve a six-pole response, forming a dual passband and generating four preset transmission zeros.

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