A Compact Waveguide Diplexer for W-Band

Abstract

The present invention discloses a compact waveguide duplexer for the W-band, comprising: a first dual-mode resonator connected to the waveguide input port, a second dual-mode resonator connected to the first waveguide output port, and a third dual-mode resonator connected to the second waveguide output port; the first dual-mode resonator is connected to the second dual-mode resonator through a first single-mode resonator and a second single-mode resonator operating in the first passband; the first dual-mode resonator is connected to the third dual-mode resonator through a third single-mode resonator and a fourth single-mode resonator operating in the second passband; the first to third dual-mode resonators are TE 301 / TE 102 -mode resonators; the first to fourth single-mode resonators are TE 101 -mode resonators. In the present invention, a dual-mode resonator based on a higher-order mode is used as a T-junction to connect the two passbands of the duplexer, reducing the footprint of the duplexer, improving the performance, having a simple structure, and being easily extended to higher frequency bands.

Description

Technical Field

[0001] The present invention belongs to the technical field of millimeter-wave radio frequency circuits, and particularly relates to a compact waveguide duplexer for the W band. Background Art

[0002] The W band refers to electromagnetic waves with a frequency coverage range of 75 - 110 GHz. Although it is at the edge of the terahertz band (0.1 - 10 THz), it still has very important significance for research in fields such as radio astronomy observations, atmospheric environment detection, and biomedical imaging.

[0003] With the rapid development of satellite microwave communication technology and the wireless mobile communication industry, spectrum resources have become increasingly scarce, and the wireless communication research field has focused on higher frequency bands. The development of millimeter-wave technology provides great potential for the research of the sixth-generation mobile communication. The development and improvement of theory are often inseparable from the support of hardware technology, and the research on millimeter-wave devices has become a very key topic in the research of wireless communication systems. Among them, as a key component of the radio frequency front-end hardware circuit, the duplexer has the function of splitting wide-spectrum signals into multiple frequency-band signals and plays a crucial role in detection and communication systems. Currently, there are various ways to implement the duplexer, such as hybrid networks, multi-stage coupling, etc. The duplexers in the prior art have problems such as relatively complex structures and difficult optimization. Summary of the Invention

[0004] To solve the deficiencies in the prior art, the present invention provides a compact waveguide duplexer for the W band, which reduces the difficulty of processing high-frequency duplexers using the CNC process, and at the same time has the characteristics of simple structure, easy optimization, low insertion loss, low return loss, and high isolation.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a compact waveguide duplexer for the W band, comprising: a first dual-mode resonator connected to the waveguide input port, a second dual-mode resonator connected to the first waveguide output port, and a third dual-mode resonator connected to the second waveguide output port; the first dual-mode resonator is connected to the second dual-mode resonator through a first single-mode resonator and a second single-mode resonator operating in the first passband; the first dual-mode resonator is connected to the third dual-mode resonator through a third single-mode resonator and a fourth single-mode resonator operating in the second passband; the first dual-mode resonator, the second dual-mode resonator, and the third dual-mode resonator are TE 301 / TE 102 -mode resonators; the first single-mode resonator, the second single-mode resonator, the third single-mode resonator, and the fourth single-mode resonator are TE 101 -mode resonators.

[0006] Further, the output directions of the first waveguide output port and the second waveguide output port are opposite.

[0007] Furthermore, the waveguide input port, the first waveguide output port, and the second waveguide output port are WR-10 waveguides, and flange joints are provided.

[0008] Furthermore, all the magnetic couplings between adjacent resonant cavities use H-plane inductive diaphragms.

[0009] Furthermore, the coupling between the resonant modes in adjacent resonant cavities is in the form of single-mode.

[0010] Furthermore, all the right angles in the resonant cavity bodies are rounded.

[0011] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: The present invention includes a dual-mode resonant cavity 1 connected to the waveguide input port, a dual-mode resonant cavity 2 connected to the first waveguide output port, and a dual-mode resonant cavity 3 connected to the second waveguide output port. The dual-mode resonant cavity 1 is connected to the dual-mode resonant cavity 2 through a single-mode resonant cavity 1 and a single-mode resonant cavity 2 operating in the first passband, and is connected to the dual-mode resonant cavity 3 through a single-mode resonant cavity 3 and a single-mode resonant cavity 4 operating in the second passband. The dual-mode resonant cavities 1 to 3 are TE 301 / TE 102 -mode resonant cavities, and the single-mode resonant cavities 1 to 4 are TE 101 -mode resonant cavities, which reduces the difficulty of processing high-frequency duplexers using the CNC process, and at the same time has the characteristics of simple structure, easy optimization, low insertion loss, low return loss, and high isolation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 FIG. is a schematic diagram of the overall structure of a compact waveguide duplexer for the W-band provided by an embodiment of the present invention;

[0013] Figure 2 is Figure 1 the split structure schematic Figure 1 ;

[0014] Figure 3 is Figure 1 the split structure schematic Figure 2 ;

[0015] Figure 4 FIG. is a schematic perspective view of the resonant cavity of a compact waveguide duplexer for the W-band provided by an embodiment of the present invention;

[0016] Figure 5 is Figure 4 a partially enlarged top view of

[0017] Figure 6It is the S-parameter test diagram of a compact waveguide duplexer for the W-band provided by an embodiment of the present invention. Among them, (a) is the complete S-parameter test diagram of the duplexer, and (b) is the locally enlarged insertion loss test diagram; S 11 is the return loss, S 21 、S 31 is the insertion loss; The TE 301 modes of the first and second dual-mode resonators and the TE 101 modes of the first and second single-mode resonators are coupled to form the first passband; The TE 102 modes of the first and third dual-mode resonators and the TE 101 modes of the third and fourth single-mode resonators are coupled to form the second passband;

[0018] Figure 7 It is the electric field distribution diagram of a compact waveguide duplexer for the W-band provided by an embodiment of the present invention at (a) 89 GHz and (b) 100 GHz;

[0019] In the figure: P1, waveguide input port; P2, first waveguide output port; P3, second waveguide output port; 10, first dual-mode resonator; 20, second dual-mode resonator; 30, third dual-mode resonator; 41, first single-mode resonator; 42, second single-mode resonator; 43, third single-mode resonator; 44, fourth single-mode resonator; 51, lower block; 52, upper block. Detailed implementation manners

[0020] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0021] The purpose of the present invention is to provide a compact waveguide duplexer for the W-band, specifically a waveguide duplexer based on the TE 301 and TE 102 hybrid modes applicable to the W-band. The duplexer adopts three dual-mode resonators and four single-mode resonators. By controlling the mode coupling, the TE 301 and TE 102 modes of the dual-mode resonators resonate at two different frequencies respectively to construct the first passband and the second passband of the duplexer. Then, the single-mode resonators work in the first passband and the second passband respectively. Using one dual-mode resonator as the common end, the two passbands are connected in parallel. Finally, a dual-mode resonator is cascaded to each of the two passbands to separate the two channels and complete the duplex operation. Its overall structure uses all magnetic coupling, which is simple and easy to implement, can effectively reduce the processing difficulty of the CNC process, and is easy to extend to higher frequencies.

[0022] The test results show that: This duplexer operates in the W band. The relative bandwidth of the first passband is 4.86%, and the return loss within the passband is generally lower than -15 dB. The relative bandwidth of the second passband is 6.49%, and the return loss within the passband is generally lower than -18 dB. It can be used to separate or combine signals of different frequency bands.

[0023] As Figures 1 to 5 shown, a compact waveguide duplexer for the W band includes: a first dual-mode resonator 10 connected to the waveguide input port P1 (source), a second dual-mode resonator 20 connected to the first waveguide output port P2 (load), and a third dual-mode resonator 30 connected to the second waveguide output port P3 (load); the first dual-mode resonator 10 is connected to the second dual-mode resonator 20 through a first single-mode resonator 41 and a second single-mode resonator 42 operating in the first passband; the first dual-mode resonator 10 is connected to the third dual-mode resonator 30 through a third single-mode resonator 43 and a fourth single-mode resonator 44 operating in the second passband; the first dual-mode resonator 10, the second dual-mode resonator 20, and the third dual-mode resonator 30 are TE 301 / TE 102 -mode resonators; the first single-mode resonator 41, the second single-mode resonator 42, the third single-mode resonator 43, and the fourth single-mode resonator 44 are TE 101 -mode resonators. The structure of this duplexer is simple and easy to be processed by the CNC process.

[0024] The waveguide input port P1, the first waveguide output port P2, and the second waveguide output port P3 are all standard rectangular waveguides and all adopt the standard WR-10 waveguide.

[0025] In the present invention, the dual-mode resonators (the first dual-mode resonator 10, the second dual-mode resonator 20, and the third dual-mode resonator 30) are in TE 301 and TE 102 modes, so that they resonate at two different frequencies to construct the first passband and the second passband; the single-mode resonators (the first single-mode resonator 41, the second single-mode resonator 42, the third single-mode resonator 43, and the fourth single-mode resonator 44) are in TE 101 mode, so that they resonate at a single frequency and operate in the first passband and the second passband respectively.

[0026] In the present invention, by utilizing the mode characteristics of the dual-mode resonator, two modes resonate at different frequencies to construct two passbands. Using one dual-mode resonator as the common end, the two passbands are connected in parallel to achieve duplex operation, and there is good isolation between the two output ports P2 and P3.

[0027] The present invention adopts TE 301 / TE 102-mode resonant cavity can control the external coupling by making the input and output coupling positions located at the center of the dual-mode resonant cavity. At this time, the coupling is the strongest. The internal coupling is controlled by adjusting the offset of the coupling position between the dual-mode cavity and the single-mode cavity to achieve duplex operation, which can reduce the design complexity.

[0028] The dual-mode resonant cavity of the present invention is connected to the source waveguide port P1, the load waveguide ports P2 and P3, and can achieve strong coupling.

[0029] In the present invention, the mode coupling between adjacent resonant cavities is in the form of single mode and can be independently controlled and adjusted in actual design; and all use H-plane inductive diaphragm coupling, that is, magnetic coupling, with a simple structure and easy processing; it can effectively avoid the problem of resonance caused by using E-plane capacitive diaphragms at low frequencies.

[0030] In the present invention, the input and output ports of the present invention both adopt standard flange joints, without other conversion and transition structures, and can be directly applied to actual measurement and wireless communication systems; the two waveguide output ports are connected by elbows to make their directions opposite, avoiding the problem of screw coincidence when installing flange joints, and at the same time making the output ports symmetrical. The inner diameter of the elbows used is 2.54 mm and the outer diameter is 5.08 mm.

[0031] The present invention is processed by the H-plane single-sided slotted waveguide structure method. As Figures 1 to 3 shown, the overall cavity structure is all processed on a metal block, and a smooth cover plate is added to form a closed cavity. The traditional CNC technology is used to mill out all the structures on the aluminum block. The diameter of the smallest drill bit during the processing is 0.5 mm, and the overall size of the duplexer is W×L×H = 33 mm×24 mm×20 mm. Standard UG-387 flange joints are processed on the waveguide port surface for easy actual measurement and application. The present invention can avoid the alignment problem of the upper block 52 and the lower block 51 during the processing of the E-plane slotted waveguide; the overall structure has the same height and is easy to mill out the structure at one time; all the cavity right angles in the model are rounded, and the radius of the rounded corner is 0.25 mm, which fits the drill bit size in the CNC process and is easy to implement.

[0032] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A compact waveguide duplexer for the W - band, characterized in that, comprising: a first dual - mode resonator (10) connected to the waveguide input port (P1), a second dual - mode resonator (20) connected to the first waveguide output port (P2), and a third dual - mode resonator (30) connected to the second waveguide output port (P3); the first dual - mode resonator (10) is connected to the second dual - mode resonator (20) through a first single - mode resonator (41) and a second single - mode resonator (42) operating in the first passband; the first dual - mode resonator (10) is connected to the third dual - mode resonator (30) through a third single - mode resonator (43) and a fourth single - mode resonator (44) operating in the second passband; The dual-mode resonators one (10), two (20), and three (30) are TE 301 / TE 102 -mode resonators. The TE 301 / TE 102 -mode resonators are used to control external coupling by making the input and output coupling positions at the center of the dual-mode resonator, and to control internal coupling by adjusting the offset of the coupling position between the dual-mode resonator and the single-mode resonator; The single-mode resonator one (41), single-mode resonator two (42), single-mode resonator three (43) and single-mode resonator four (44) are TE 101 mode resonators; the output directions of the first waveguide output port (P2) and the second waveguide output port (P3) are opposite; all the magnetic couplings between adjacent resonators use H - plane inductive diaphragms; the couplings between the resonant modes in adjacent resonators are all in single - mode form.

2. The compact waveguide duplexer for the W - band according to claim 1, characterized in that, the waveguide input port (P1), the first waveguide output port (P2) and the second waveguide output port (P3) are WR - 10 waveguides and are provided with flange joints.

3. The compact waveguide duplexer for the W - band according to claim 1, characterized in that, the right - angled corners in all the resonator cavities are rounded.

Images