Waveguide duplexer for dual-band probe and application

Abstract

The invention discloses a waveguide duplexer for a dual-band probe and application. The waveguide duplexer comprises a common end waveguide port, a D-waveband standard waveguide port, a G-waveband standard waveguide port, a non-standard waveguide channel of a common end, a stepped transition structure from a non-standard waveguide to a ridge waveguide, and a T-shaped connection structure among a high-frequency channel, a low-frequency channel and a common end channel. The invention discloses an impedance matching structure for transition from a connection structure to a low-frequency channel, the low-frequency channel, a transition structure from the low-frequency channel to a D-band standard waveguide, a high-frequency channel and a transition structure from the high-frequency channel to a G-band standard waveguide, and relates to the technical field of microwave radio frequency testing. The transition structure from each channel to the standard waveguide of the corresponding wave band provides an interface connected with other devices or equipment, and has the good channel transmission characteristics of low loss, good isolation between channels and the like, and as most structures adopt the ridge waveguide design, the working bandwidth is wide and the device structure is compact on the premise of large power capacity.

Description

Technical Field

[0001] The invention belongs to the technical field of microwave radio frequency testing, and in particular relates to a waveguide duplexer for a dual-band probe and an application thereof. Background Art

[0002] In recent years, with the development of communication technology and the advancement of processing technology, applications in the millimeter wave to terahertz band have increasingly shown a trend towards high frequency and wide bandwidth. However, since transmission lines working in the millimeter wave and above frequency bands have interfaces of different shapes and sizes, they need to be connected to other devices with the help of fixtures or transition structures, making it difficult to achieve on-chip testing.

[0003] In order to solve this difficulty, the RF probes used for on-chip testing have been extensively and deeply studied, and many probes with different structures and materials have been born. The Ground-Signal-Ground (GSG) probe, which is more commonly used today, has a planar structure at one end that is convenient for direct contact with the device, and a waveguide or coaxial line interface at the other end, which is used to connect to the vector network analyzer for testing. Among them, the coaxial line can achieve a wider operating frequency band, but due to the presence of the medium, the loss will be seriously deteriorated at high frequencies. Although the waveguide has a large power capacity and low loss, due to the limitations of the transmission mode characteristics, a single waveguide can theoretically only support single-mode transmission of one octave at most. In addition, considering that a standard waveguide needs to be used between the device and the instrument, the operating bandwidth and frequency band range are further limited.

[0004] In order to realize a wide-band probe that works in the millimeter wave and higher frequency range, an effective method is to add a duplexer or multiplexer between the probe and the vector network analyzer, thereby dividing the working frequency band of the probe into two or even more frequency bands that can be covered by standard waveguides. As important devices for separating or synthesizing signals of different frequency bands, duplexers and multiplexers have important applications in many fields. As for the duplexer, its structure has many forms, and it can be designed comprehensively using bandpass filters and bandstop filters, high-pass filters and low-pass filters, or bandpass filters and high-pass / low-pass filters. When combining two channels and a common port, a T-junction or a Y-junction is generally used as the connection structure.

[0005] However, a duplexer composed of two independently designed channel filters may have a certain gap between the two channels, resulting in a waste of spectrum resources. In order to eliminate the gap between the two frequency band channels, that is, to realize a continuous passband duplexer, a complementary filter is required so that the sum of the input impedance of the two filters at the common port is a real constant in the working frequency band of the duplexer. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides a design method of a waveguide duplexer for a dual-band probe, aiming to design a dual-band duplexer structure with low loss, good isolation and compact structure.

[0007] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a waveguide duplexer for a dual-band probe, comprising a common end waveguide port, a D-band standard waveguide port, a G-band standard waveguide port, a non-standard waveguide channel at the common end, a stepped transition structure from the non-standard waveguide to the ridge waveguide, a T-type connection structure, an impedance matching structure, a low-frequency channel, a transition structure, a high-frequency channel, and a transition structure, wherein the T-type connection structure is arranged between the high-frequency channel, the low-frequency channel, and the common end channel; wherein the non-standard waveguide channel at the common end is used to connect to the waveguide port of the probe; the stepped transition structure from the non-standard waveguide to the ridge waveguide The transition structure realizes mode and impedance matching between the non-standard waveguide and the ridge waveguide; the T-type connection structure has three ports, among which the port connected to the low-frequency channel introduces an impedance matching structure for the transition of the connection structure to the low-frequency channel, and the other two ports of the T-type connection structure are directly connected to the high-frequency channel and the common end channel respectively; the low-frequency channel adopts a single-ridge waveguide low-pass filter, and the high-frequency channel adopts a single-ridge waveguide band-pass filter; the low-frequency channel is connected in sequence to the transition structure from the low-frequency channel to the D-band standard waveguide and the D-band standard waveguide port; the high-frequency channel is connected in sequence to the transition structure from the high-frequency channel to the G-band standard waveguide and the G-band standard waveguide.

[0008] Furthermore, the steps between the impedance matching structure and the T-type connection structure achieve complementarity within the passband, and the sum of the input impedances of the two is approximately a real constant within the passband.

[0009] Furthermore, the single-ridged waveguide low-pass filter of the low-frequency channel is formed by connecting single-ridged waveguides with various sizes and evanescent mode waveguides.

[0010] Furthermore, the single ridge waveguide bandpass filter of the high frequency channel is formed by connecting ridge waveguide resonant cavities with different sizes and impedance converters.

[0011] Furthermore, the T-type connection structure uses ridge waveguides with heights different from the ridge height in the common channel at the intersections with the low-frequency channel and the high-frequency channel, respectively, to match the input impedances of the two channels.

[0012] Furthermore, the impedance matching structure where the connection structure transitions to the low-frequency channel adopts a waveguide wall with a gradually changing inner width to enhance the isolation between the two channels.

[0013] Furthermore, the stepped transition structure from the non-standard waveguide to the ridge waveguide, the transition structure from the low-frequency channel to the D-band standard waveguide, and the transition structure from the high-frequency channel to the G-band standard waveguide are all composed of three sections of ridge waveguides of different sizes and one section of gradient height waveguide.

[0014] Furthermore, the height of the gradually variable height waveguide in the transition structure gradually decreases in the direction of the D-band standard waveguide, the height of the gradually variable height waveguide in the transition structure gradually decreases in the direction of the G-band standard waveguide, and the height of the gradually variable height waveguide in the stepped transition structure gradually decreases in the direction of the non-standard waveguide; at the stepped transition structure from the non-standard waveguide to the ridge waveguide, the transition structure from the low-frequency channel to the D-band standard waveguide, and the transition structure from the high-frequency channel to the G-band standard waveguide, the wide side size of the ridge waveguide changes synchronously with the gradually variable height waveguide, and the wide side size of the ridge waveguide increases while the ridge height decreases.

[0015] Furthermore, all right angles of the structures within the cavity are rounded.

[0016] The application of the waveguide duplexer for the dual-band probe is used to separate or synthesize signals of different frequency bands.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The duplexer designed by the present invention has good channel transmission characteristics such as low loss and good isolation between channels. The single ridge waveguide and the evanescent mode waveguide, as well as the ridge waveguide resonator and the impedance converter are respectively used to realize the filters of the low frequency band and the high frequency band, thereby ensuring good passband performance. At the same time, the input impedance of the two filters is optimized and designed, and an impedance matching structure is introduced at the intersection to ensure that the input impedance of the common port is approximately a constant real value within the working bandwidth, thereby realizing a duplexer with a continuous passband. At the ends of the high frequency band and the low frequency band, a stepped transition structure from the ridge waveguide to the corresponding standard rectangular waveguide is respectively designed, thereby realizing the matching of the mode and impedance between the ridge waveguide and the rectangular waveguide. Under the premise of ensuring good loss performance, a universal waveguide interface is provided for testing and interconnection between devices. Since most structures adopt the ridge waveguide design, under the premise of large power capacity, the working bandwidth is wide and the device structure is compact. In addition, thanks to the design of the low-pass and band-pass complementary filters, a duplexer with a continuous passband is realized, unnecessary waste of bandwidth resources is avoided, and it is beneficial to obtain a relatively accurate test result when connected to a radio frequency probe for testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the prior art solutions, the drawings used in the embodiments or the prior art solutions are briefly introduced below. It should be noted that the drawings described below are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0019] The present invention will design a duplexer based on complementary filter design, which can provide certain reference significance for the development of duplexers and dual-band probes in the future millimeter wave / terahertz field.

[0020] Figure 1 A left view of an overall schematic diagram of a waveguide duplexer for a dual-band probe provided by an embodiment of the present invention; Figure 2 A right view of an overall schematic diagram of a waveguide duplexer for a dual-band probe provided by an embodiment of the present invention; Figure 3a A half-section view of a high-frequency channel, a low-frequency channel and a common-end channel of a waveguide duplexer for a dual-band probe provided in an embodiment of the present invention; Figure 3b An oblique isometric view of a high-frequency channel, a low-frequency channel and a common-end channel of a waveguide duplexer for a dual-band probe provided in an embodiment of the present invention; Figure 4 A schematic diagram of a block processing structure of a waveguide duplexer for a dual-band probe provided by an embodiment of the present invention; Figure 5 The return loss and insertion loss performance diagram of the duplexer proposed by the present invention are schematically shown; Figure 6 The diagram schematically shows a simulation diagram of the isolation performance between two channels of the duplexer proposed in the present invention.

[0021] In the accompanying drawings, 1-common end waveguide port, 2-D band standard waveguide port, 3-G band standard waveguide port, 4-non-standard waveguide channel, 5-step transition structure, 6-T-type connection structure, 7-impedance matching structure, 8-low frequency channel, 9-first transition structure, 10-high frequency channel, 11-second transition structure. DETAILED DESCRIPTION

[0022] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be noted that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the claims of the present invention.

[0023] In the description of the embodiments of the present invention, it should be understood that the orientations or positional relationships indicated by terms such as “horizontal direction” and “vertical direction” are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and cannot be considered that the indicated elements or devices are in specific orientations.

[0024] The present invention provides a waveguide duplexer for a dual-band probe, comprising a common-end waveguide port 1, a D-band standard waveguide port 2, a G-band standard waveguide port 3, a common-end non-standard waveguide channel 4, a non-standard waveguide to ridge waveguide stepped transition structure 5, a T-type connection structure 6, an impedance matching structure 7, a low-frequency channel 8, a transition structure 9, a high-frequency channel 10, and a transition structure 11, wherein the T-type connection structure 6 is arranged between the high-frequency channel 10, the low-frequency channel 8 and the common-end channel; wherein the common-end non-standard waveguide channel 4 is used to connect with the waveguide port of the probe; the non-standard waveguide to ridge waveguide stepped transition structure 5 realizes mode and impedance matching between the non-standard waveguide and the ridge waveguide; the T-type connection structure 6 has three Ports, among which the port connected to the low-frequency channel introduces an impedance matching structure 7 for transitioning the connection structure to the low-frequency channel, and the other two ports of the T-type connection structure 6 are directly connected to the high-frequency channel 10 and the common end channel respectively; the low-frequency channel 8 adopts a single-ridge waveguide low-pass filter, and the high-frequency channel 10 adopts a single-ridge waveguide band-pass filter; the low-frequency channel 8 is used to transmit signals in the frequency range of 110GHz~164GHz, and is sequentially connected to the transition structure 9 from the low-frequency channel to the D-band standard waveguide and the D-band standard waveguide port 2; the high-frequency channel 10 is used to transmit signals in the frequency range of 164GHz~220GHz, and is sequentially connected to the transition structure 11 from the high-frequency channel to the G-band standard waveguide and the G-band standard waveguide 3.

[0025] In the description of the embodiments of the present invention, the given structural dimensions are preferred parameters. With reference to the embodiments of the present invention, the dimensional parameters of each component may be modified to further obtain the actual required performance.

[0026] According to existing research, complementary filters can be realized by various structural designs such as high-pass filter and low-pass filter, band-pass filter and band-stop filter, low-pass filter and band-pass filter. Among them, the flattest low-pass filter and its corresponding high-pass filter, the flattest band-pass filter and its corresponding band-stop filter can theoretically realize complementary filters. However, due to the equiripple effect in the filter passband, the Chebyshev low-pass filter and its corresponding high-pass filter, the Chebyshev band-pass filter and its corresponding band-stop filter can only realize approximate complementary filters, that is, the input impedance of the common port is approximately a real constant within the duplexer working bandwidth. Similarly, a reasonably designed low-pass filter and band-pass filter can also realize an approximate complementary filter that basically meets the characteristics of a continuous passband duplexer. After comprehensively considering the requirements of performance indicators and processing technology, the present invention adopts a low-pass filter, a band-pass filter and a T-junction connecting the two to realize a continuous passband duplexer.

[0027] See also Figure 1 , Figure 1 A left view of an overall schematic diagram of a waveguide duplexer for a dual-band probe provided by an embodiment of the present invention, Figure 2The right view of the overall schematic diagram of a waveguide duplexer for a dual-band probe provided by an embodiment of the present invention; the illustrated structure includes a common end waveguide port 1, a D-band standard waveguide port 2, and a G-band standard waveguide port 3, and the waveguide duplexer as a whole includes a main structure and three waveguide flanges corresponding to the common port, the low-frequency port, and the high-frequency port; the flange is a part that connects the waveguide ports to each other, and the waveguide flange is a flange fixed on the waveguide terminal according to the design, and can be installed with accessories for alignment and clamping with the matching flange. The dimensions of all waveguide flanges in the embodiment of the present invention are standard waveguide flange dimensions, the dimensions of the common end waveguide interface 1 are 1.7mm×0.65mm, the dimensions of the low-frequency end waveguide interface corresponding to the D-band standard waveguide port 2 are 1.651mm×0.826mm, the dimensions of the high-frequency end waveguide interface corresponding to the G-band standard waveguide port 3 are 1.295mm×0.648mm, and the thickness of the waveguide flange is 4mm.

[0028] Figure 3a A half-section view of a high-frequency channel, a low-frequency channel and a common-end channel of a waveguide duplexer for a dual-band probe provided in an embodiment of the present invention; Figure 3bAn oblique isometric view of a high-frequency channel, a low-frequency channel, and a common-end channel of a waveguide duplexer for a dual-band probe provided in an embodiment of the present invention; the illustrated structure includes a non-standard waveguide channel 4 at the common end, a stepped transition structure 5 from the non-standard waveguide to the ridge waveguide, a T-type connection structure 6 between the high-frequency channel, the low-frequency channel, and the common-end channel, an impedance matching structure 7 for the transition of the T-type connection structure 6 to the low-frequency channel 8, the low-frequency channel 8, a first transition structure 9 from the low-frequency channel to the D-band standard waveguide, a high-frequency channel 10, and a high-frequency channel to the G-band standard waveguide The second transition structure 11; wherein the non-standard waveguide channel 4 at the common end is used to connect to the waveguide port of the dual-band probe; the stepped transition structure 5 from the non-standard waveguide to the ridge waveguide realizes impedance matching between the non-standard waveguide and the ridge waveguide in the common end channel by adopting a ridge waveguide with gradually changing wide side size and gradually changing ridge height. The single-mode operating frequency of the ridge waveguide in the common end channel is 97GHz~234GHz, so that only the main mode is transmitted in the duplexer, and the high-order mode is suppressed; T-type connection structure between the high-frequency channel, the low-frequency channel and the common end channel 6 has three ports for matching the common end and eliminating the mutual influence between the low-frequency channel 8 and the high-frequency channel 10; ridge waveguides of different heights and lengths are loaded in the connection with the low-frequency channel 8 and the high-frequency channel 10, so that each channel remains in an open circuit state at the working frequency of the other channels, ensuring good transmission characteristics in the two channels; the port where the T-type connection structure 6 is connected to the low-frequency channel 8 introduces an impedance matching structure 7 for transitioning the connection structure to the low-frequency channel, and adopts a structure in which the wide side of the waveguide inside is gradually changed to achieve impedance matching and reduce the signal between the two channels. The low-frequency channel 8 is used to transmit signals in the frequency range of 110 GHz to 164 GHz, and is sequentially connected to the first transition structure 9 from the low-frequency channel to the D-band standard waveguide and the D-band standard waveguide port 2, so as to facilitate connection with the D-band spread spectrum module; the high-frequency channel 10 is used to transmit signals in the frequency range of 164 GHz to 220 GHz, and is sequentially connected to the second transition structure 11 from the high-frequency channel to the G-band standard waveguide and the G-band standard waveguide port 3, so as to facilitate connection with the G-band spread spectrum module.

[0029] The low-frequency channel 8 is designed to adopt a single-ridged waveguide low-pass filter; the high-frequency channel 10 is designed to adopt a single-ridged waveguide bandpass filter; the two filters are connected to the impedance matching structure 7 that transitions to the low-frequency channel and the steps between the high-frequency channel and the high-frequency channel, the low-frequency channel and the common end channel to achieve complementarity within the passband, that is, the sum of the input impedances of the two is approximately a real constant within the passband, thereby achieving continuity of the high-frequency passband and the low-frequency passband.

[0030] A single-ridged waveguide low-pass filter design is adopted in the low-frequency channel 8, which is composed of a single-ridged waveguide with different sizes connected to an evanescent mode waveguide. Since the connection between the single-ridged waveguide and the evanescent mode waveguide introduces discontinuity, it can be equivalent to a cascade of inductance and capacitance in the low-pass filter prototype, thereby achieving stopband suppression and high steepness. A single-ridged waveguide bandpass filter design is adopted in the high-frequency channel 10, which is composed of a ridged waveguide resonant cavity with different sizes connected to an impedance converter, wherein the wider ridge waveguide serves as the resonant unit of the bandpass filter, and the narrower ridge waveguide serves as an impedance converter coupled between the resonant units, thereby achieving a bandpass filter with a relative bandwidth of 29%.

[0031] The T-type connection structure 6 between the high-frequency channel, the low-frequency channel and the common-end channel is loaded with ridge waveguides of different heights and lengths in the connection with the low-frequency channel and the high-frequency channel, so that each channel remains in an open circuit state at the working frequency of other channels, ensuring good transmission characteristics in the two channels; the port connected to the low-frequency channel introduces an impedance matching structure 7 for transitioning the connection structure to the low-frequency channel, and adopts a triangular structure with a gradual change in the width of the waveguide to achieve impedance matching, reduce signal crosstalk between the two channels, and prevent the high-frequency channel from having a large resonance point in the passband; The stepped transition structure 5 from the non-standard waveguide to the ridge waveguide, the first transition structure 9 from the low-frequency channel to the D-band standard waveguide, and the second transition structure 11 from the high-frequency channel to the G-band standard waveguide are all composed of three sections of ridge waveguides of different sizes and one section of gradient height waveguide, wherein the gradient height waveguide transforms the three waveguide ports into waveguide transmission lines of the same length in the vertical direction, the wide side size and the ridge height of the ridge waveguide are synchronously stepped, and the wide side size of the ridge waveguide increases while the ridge height decreases, which can be equivalent to an impedance converter for realizing the transition from the waveguide to the input ridge waveguides of the three channels in the horizontal direction; the height of the gradient height waveguide in the first transition structure 9 gradually decreases in the direction of the D-band standard waveguide, the height of the gradient height waveguide in the second transition structure 11 gradually decreases in the direction of the G-band standard waveguide, and the height of the gradient height waveguide in the stepped transition structure 5 gradually decreases in the direction of the non-standard waveguide.

[0032] Figure 4 The diagram shows the block diagram of the duplexer according to CNC processing requirements. Part A includes part of the waveguide cavity and the metal ridge structure, and part B includes the remaining part of the waveguide cavity.

[0033] The waveguide duplexer used for the dual-band probe described in this embodiment has an operating frequency band of 110 GHz to 220 GHz, wherein the low-frequency channel has an operating frequency band of 110 GHz to 164 GHz, and the high-frequency channel has an operating frequency band of 164 GHz to 220 GHz. Figure 5 As shown, S of this embodiment 11The operating frequency range of 110GHz~220GHz is kept below -20dB; S 21 The signal level is kept above -3.6dB in the 110GHz~164GHz band, above -1dB in the 110GHz~162GHz band, and below -40dB in the 178GHz~220GHz band. 31 The loss is kept above -3.6dB in 164GHz~220GHz, above -1dB in 167GHz~220GHz, and below -40dB in 110GHz~149GHz. This shows that the embodiment has a low loss in the working frequency band, and can split the signal into corresponding channels according to the frequency band, and has a good suppression effect in the stop band. Figure 6 As shown, S represents the isolation effect between the two channels. 23 The parameter is lower than -7dB in the full operating frequency band of the duplexer, indicating that the crosstalk between the two channels is small.

[0034] In the embodiment of the present invention, all right angles in the cavity are rounded to meet the needs of CNC machine tool processing.

[0035] The above is a description of the design method of the waveguide duplexer for the dual-band probe provided by the present invention. For those skilled in the art, according to the idea of ​​the embodiment of the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A waveguide duplexer for a dual-band probe, characterized in that: The invention comprises a common end waveguide port (1), a D-band standard waveguide port (2), a G-band standard waveguide port (3), a common end non-standard waveguide channel (4), a non-standard waveguide to ridge waveguide stepped transition structure (5), a T-type connection structure (6), an impedance matching structure (7), a low-frequency channel (8), a transition structure (9), a high-frequency channel (10), and a transition structure (11), wherein the T-type connection structure (6) is arranged between the high-frequency channel (10), the low-frequency channel (8), and the common end channel; wherein the common end non-standard waveguide channel (4) is used to connect to the waveguide port of the probe; the non-standard waveguide to ridge waveguide stepped transition structure (5) is used to connect the non-standard waveguide to the ridge waveguide. The T-type connection structure (6) has three ports, wherein the port connected to the low-frequency channel introduces an impedance matching structure (7) for transitioning the connection structure to the low-frequency channel, and the other two ports of the T-type connection structure (6) are directly connected to the high-frequency channel (10) and the common end channel respectively; the low-frequency channel (8) adopts a single-ridge waveguide low-pass filter, and the high-frequency channel (10) adopts a single-ridge waveguide band-pass filter; the low-frequency channel (8) is sequentially connected to the transition structure (9) from the low-frequency channel to the D-band standard waveguide and the D-band standard waveguide port (2); the high-frequency channel (10) is sequentially connected to the transition structure (11) from the high-frequency channel to the G-band standard waveguide and the G-band standard waveguide (3).

2. The waveguide duplexer for dual-band probe according to claim 1, characterized in that: The step between the impedance matching structure (7) and the T-type connection structure (6) realizes complementarity within the passband, and the sum of the input impedances of the two is approximately a real constant within the passband.

3. The waveguide duplexer for dual-band probe according to claim 2, characterized in that: The single-ridge waveguide low-pass filter of the low-frequency channel (8) is composed of single-ridge waveguides with various sizes connected to evanescent mode waveguides.

4. The waveguide duplexer for dual-band probe according to claim 2, characterized in that: The single ridge waveguide bandpass filter of the high frequency channel (10) is formed by connecting ridge waveguide resonant cavities with different sizes and impedance converters.

5. The waveguide duplexer for dual-band probe according to claim 1, characterized in that: The T-type connection structure (6) uses ridge waveguides with different heights from the ridge height in the common channel at the intersections with the low-frequency channel (8) and the high-frequency channel (10), respectively, to match the input impedances of the two channels.

6. The waveguide duplexer for dual-band probe according to claim 1, characterized in that: The impedance matching structure (7) at the transition from the connection structure to the low-frequency channel adopts a waveguide wall with a gradually changing inner width to enhance the isolation between the two channels.

7. The waveguide duplexer for dual-band probe according to claim 1, characterized in that: The stepped transition structure (5) from the non-standard waveguide to the ridge waveguide, the transition structure (9) from the low-frequency channel to the D-band standard waveguide, and the transition structure (11) from the high-frequency channel to the G-band standard waveguide are all composed of three sections of ridge waveguides of different sizes and one section of gradient height waveguide.

8. The waveguide duplexer for dual-band probe according to claim 1, characterized in that: The height of the gradually variable height waveguide in the transition structure (9) gradually decreases in the direction of the D-band standard waveguide, the height of the gradually variable height waveguide in the transition structure (11) gradually decreases in the direction of the G-band standard waveguide, and the height of the gradually variable height waveguide in the stepped transition structure (5) gradually decreases in the direction of the non-standard waveguide. The wide side size of the ridge waveguide at the stepped transition structure (5) from the non-standard waveguide to the ridge waveguide, the transition structure (9) from the low-frequency channel to the D-band standard waveguide, and the transition structure (11) from the high-frequency channel to the G-band standard waveguide changes synchronously with the gradually variable height waveguide, and the wide side size of the ridge waveguide increases while the ridge height decreases.

9. The waveguide duplexer for dual-band probe according to claim 1, characterized in that: All right angles in the cavity are rounded.

10. The use of a waveguide duplexer for a dual-band probe according to any one of claims 1 to 9, characterized in that: Used to separate or synthesize signals in different frequency bands.

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