Microwave guide millimeter wave ridge waveguide dual directional coupler with high coupling flatness

Abstract

The application discloses a kind of millimeter wave coupling coefficient high flatness double directional coupler, the coupler specifically includes main ridge waveguide as microwave main transmission channel, auxiliary ridge waveguide as signal sampling channel and coupling small hole, auxiliary ridge waveguide is arranged in parallel in the two sides of main ridge waveguide;The structure of main ridge waveguide is the double-ridge waveguide of different ridge from top to bottom;Auxiliary ridge waveguide is single-ridge waveguide, and the structure and size of two sides of auxiliary ridge waveguide are same;Two sides of main ridge waveguide are communicated with auxiliary ridge waveguide by coupling small hole respectively, and coupling small hole is used to communicate main auxiliary waveguide and as coupling channel.Microwave signal is input from one end of main ridge waveguide, and most signal energy is transmitted to the other end of main ridge waveguide, and a small part of signal energy is coupled into auxiliary ridge waveguide by the coupling channel of main ridge waveguide H face.The ridge waveguide double directional coupler provided by the application is suitable for microwave, millimeter wave, terahertz field, and has the advantages of high coupling output flatness, wide operating frequency band, low return loss and good directivity.

Description

Technical Field

[0001] This invention belongs to the field of coupler technology, specifically relating to a microwave-guided millimeter-wave ridge waveguide dual directional coupler with high coupling flatness. Background Technology

[0002] A directional coupler is an important multi-port broadband matching network in microwave systems, commonly used for power distribution and combining in system networks, and also for signal phase conversion. In the microwave field, directional couplers are widely used in various types of microwave circuits, including frequency converters, filters, power dividers, and antenna feed networks. Currently, with technological advancements, the operating frequency band of directional couplers is continuously increasing. The application of terahertz frequencies and the increasing precision required in microwave systems place higher demands on the design of directional couplers.

[0003] Directional couplers can be classified into various types based on their structure, such as waveguide directional couplers, microstrip line directional couplers, coaxial line directional couplers, and stripline directional couplers. Waveguide directional couplers typically achieve signal coupling by creating apertures in the common walls of the two waveguides. Single-aperture waveguide directional couplers often operate within an extremely narrow bandwidth. To increase the operating bandwidth of waveguide directional couplers, a common method is to create more coupling apertures in the common walls of the waveguides. However, as the operating bandwidth increases, the coupling strength fluctuates significantly with frequency, which has a certain impact on engineering applications. Summary of the Invention

[0004] The present invention aims to provide a novel ridge waveguide directional coupler to solve the problem of significant fluctuations in coupling strength within the bandwidth of the broadband waveguide directional coupler mentioned above, thereby meeting the requirements of engineering applications for the coupling signal strength to fluctuate within a small range.

[0005] To achieve the above objectives, the present invention provides a microwave-millimeter-wave ridge waveguide dual directional coupler with high coupling flatness, comprising a main ridge waveguide as the main microwave transmission channel, a secondary ridge waveguide as the signal sampling channel, and a coupling aperture, wherein the secondary ridge waveguide is arranged parallel to both sides of the main ridge waveguide. The main ridge waveguide has a double ridge waveguide with different ridges on the top and bottom; the secondary ridge waveguide is a single ridge waveguide, and the secondary ridge waveguides on both sides have the same structure and size; the main ridge waveguide is connected to the secondary ridge waveguide on both sides through coupling apertures, which are used to connect the main and secondary waveguides and serve as coupling channels.

[0006] A further improvement of the present invention is that the upper and lower ridges of the main ridge waveguide have the same width s, while the lower ridge has a narrow side s. and the narrow side of the upper ridge The ratio range is 3:1 to 3:2.

[0007] A further improvement of the present invention is that the sub-ridge waveguide is provided with a lower ridge, and the size of the lower ridge of the sub-ridge waveguide is the same as the size of the lower ridge of the main ridge waveguide.

[0008] A further improvement of the present invention is that the main ridge waveguide and the secondary ridge waveguide are placed side by side along the narrow wall of the waveguide.

[0009] A further improvement of the present invention is that the coupling aperture and the H-plane of the main and secondary ridge waveguides are located on the same plane.

[0010] A further improvement of the present invention is that the number of coupling holes is determined by the operating bandwidth; the wider the operating bandwidth, the more coupling holes are required.

[0011] A further improvement of the present invention is that the coupling apertures are arranged at equal intervals, and the distance between the centers of the coupling apertures is equal to the waveguide wavelength. One-quarter of it.

[0012] A further improvement of the present invention is that the coupling holes are symmetrically distributed about the center position, with the largest coupling hole at the center position and the size of the coupling holes decreasing sequentially as they extend to both ends.

[0013] A further improvement of the present invention is that the cross-section of the coupling aperture is rectangular or circular, or designed as a coupling slit.

[0014] A further improvement of this invention is that the operating frequency band is 170GHz-260GHz. Below -25dB.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a microwave-guided millimeter-wave ridge waveguide dual directional coupler with high coupling flatness. Signals are coupled through the H-plane of the waveguides. The difference in the main and secondary waveguide structures results in a decrease in coupling at lower frequencies in the operating band compared to traditional ridge waveguide couplers. This ultimately leads to a relatively improved coupling flatness across the entire bandwidth, while maintaining good directivity, good isolation, and low insertion loss. Compared to existing technologies, this invention provides a better method for improving the coupling flatness of directional couplers, meeting the higher requirements for coupling power fluctuations in engineering applications. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention, the accompanying drawings used in the description of the invention are briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1A schematic diagram of the structure of the dual directional coupler proposed in this invention is shown. Figure 2 A schematic front view of the dual directional coupler proposed in this invention is shown. Figure 3 A schematic diagram of a cross-sectional view of the coupling aperture of the dual-directional coupler proposed in this invention is shown. Figure 4 The S-parameter diagram of the dual directional coupler proposed in this invention is schematically shown. Figure 5 The directional pattern of the dual directional coupler proposed in this invention is schematically shown. Figure 6 The diagram illustrates a comparison of the coupling bandwidth fluctuations between the dual directional coupler proposed in this invention and a traditional directional coupler.

[0018] In the attached diagram, 1-main ridge waveguide, 2-two side sub-ridge waveguides, 3-coupling aperture, 4-lower ridge, 5-upper ridge, 6-lower ridge of the first sub-ridge waveguide, 7-lower ridge of the second sub-ridge waveguide, 11-first port, 12-second port, 21-third port, 22-fourth port, 23-fifth port, 24-sixth port. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The structural forms and arrangements described in the following specific examples are only used to concisely express the present invention, and are only examples, not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] The present invention will now be described in further detail with reference to the accompanying drawings: The millimeter-wave coupling coefficient high flatness dual directional coupler disclosed in this embodiment of the invention includes a main ridge waveguide 1 as the main microwave transmission channel, two secondary ridge waveguides 2 as signal sampling channels, and a coupling aperture 3 for connecting the main and secondary waveguides as a coupling channel.

[0022] The main ridge waveguide 1 and two secondary ridge waveguides 2 are placed parallel to each other with the waveguide H-plane as a common wall. The main ridge waveguide 1 and the two secondary ridge waveguides 2 are isolated from each other and coupled through a coupling channel 3. The main ridge waveguide 1 and the two secondary ridge waveguides 2 have the same long side a, wide side b, and length L. The waveguide dimensions are determined by their operating frequency band. The main ridge waveguide 1 is a double-ridge waveguide, with a lower ridge 4 and an upper ridge 5 located at the center of the lower and upper walls, respectively. The lengths of the lower ridge 4 and upper ridge 5 are the same as the waveguide length L, and their wide side s is the same. and The ratio range is 3:1 to 3:2. Both the first and second sub-ridge waveguides are single-ridge waveguides. The lower walls of the first and second sub-ridge waveguides are respectively provided with a lower ridge 6 and a lower ridge 7. The dimensions of the lower ridge 6 and the lower ridge 7 are exactly the same as the lower ridge 4 of the main ridge waveguide. The coupling apertures 3 can be rectangular, circular, or other polygonal shapes, or they can be designed as coupling slots. The coupling apertures 3 are evenly distributed about the center of the waveguide, with the largest size in the middle and decreasing towards both sides.

[0023] Fabricate the above-mentioned high-flatness dual-directional coupler with high millimeter-wave coupling coefficient according to the following dimensions: The axial length L of the coupler is 15mm. The long side a of the main ridge waveguide and the two side sub-ridge waveguides is 0.9mm, and the narrow side b is 0.45mm. The lower ridge of the main ridge waveguide has a long side of 0.2mm and a narrow side of 0.15mm, while the upper ridge has a long side of 0.2mm and a narrow side of 0.1mm. The ridges of the two side sub-ridge waveguides each have a long side of 0.2mm and a narrow side of 0.15mm. In this embodiment, the coupling apertures are square through-holes that penetrate the common wall of the main ridge waveguide and the two side sub-ridge waveguides. The height of the apertures is the same as the narrow side dimension of the waveguides, which is 0.45mm. The center-to-center distance between the coupling apertures is 0.53mm, and the size of the middle coupling aperture is 0.42mm. The apertures gradually decrease in size towards both sides, with a size difference of 0.01mm between adjacent apertures. This embodiment uses 19 coupling apertures for signal coupling.

[0024] The microwave-millimeter-wave ridge waveguide dual-directional coupler with high coupling flatness described in this embodiment operates in the 170GHz-260GHz frequency band. This dual-directional coupler includes six ports. Within the operating frequency band, the first port 11 is the main ridge waveguide port. Both the first port 11 and the second port 12 serve as signal input and output ports. Signals input from the first port 11 will be output from the second port 12, with a portion coupled to the fourth port 22. The third port 21 is an isolation port connected to an absorbing load. Signals input from the second port 12 will be output from the first port 11, with a portion coupled to the fifth port 23. The sixth port 24 is an isolation port connected to an absorbing load. In wireless communication systems, the dual-directional coupler couples two different signal sources, allowing them to coexist in the circuit and transmit in both directions. Figure 6 As shown, this embodiment operates within the 170-260GHz frequency band. All can be guaranteed to be below -25dB. They can all stay below -35dB. Basically 0dB, The fact that the value remains around 10dB indicates that this embodiment can maintain good coupling performance over a fairly wide bandwidth. Figure 5 This indicates that the directivity of this embodiment remains below -25dB throughout the entire operating frequency band, demonstrating its excellent directivity. To highlight the difference between this embodiment and traditional ridge waveguide directional couplers, in... Figure 6 In this paper, we compared the coupling fluctuation of the dual directional coupler proposed in this invention with that of the traditional directional coupler. The results show that the coupling fluctuation of the proposed embodiment is significantly smaller than that of the traditional ridge waveguide directional coupler.

[0025] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention, such as adjusting the narrow side lengths of the upper and lower ridges of the main ridge waveguide, changing the shape of the coupling aperture, etc. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A microwave-guided millimeter-wave ridge waveguide dual directional coupler with high coupling flatness, characterized in that, It includes a main ridge waveguide (1) as the main microwave transmission channel, a secondary ridge waveguide (2) as the signal sampling channel, and a coupling aperture (3); the secondary ridge waveguide (2) is arranged parallel to both sides of the main ridge waveguide (1); The main ridge waveguide (1) has a double-ridge waveguide structure with different ridges on the top and bottom; the secondary ridge waveguide (2) is a single-ridge waveguide, and the structures and dimensions of the secondary ridge waveguides on both sides are the same; the main ridge waveguide (1) is connected to the secondary ridge waveguide (2) on both sides through coupling apertures (3), and the coupling apertures (3) are used to connect the main and secondary waveguides and serve as coupling channels; the secondary ridge waveguide (2) is provided with a lower ridge, and the size of the lower ridge of the secondary ridge waveguide (2) is the same as the size of the lower ridge of the main ridge waveguide (1); the coupling apertures (3) are located on the same plane as the H-plane of the main and secondary ridge waveguides; the coupling apertures (3) are arranged at equal intervals, and the distance between the centers of the coupling apertures (3) is equal to the waveguide wavelength. One-quarter; the upper and lower ridges of the main ridge waveguide (1) have the same wide side s, and the lower ridge has the same narrow side s. and the narrow side of the upper ridge The ratio range is 3:1 to 3:2; the operating frequency band is 170GHz-260GHz. Below -25dB.

2. The microwave-guided millimeter-wave ridge waveguide dual directional coupler with high coupling flatness according to claim 1, characterized in that, The main ridge waveguide (1) and the secondary ridge waveguide (2) are placed side by side along the narrow wall of the waveguide.

3. The microwave-guided millimeter-wave ridge waveguide dual directional coupler with high coupling flatness according to claim 1, characterized in that, The number of coupling holes (3) is determined by the working bandwidth. The wider the working bandwidth, the more coupling holes (3) are required.

4. The microwave-guided millimeter-wave ridge waveguide dual directional coupler with high coupling flatness according to claim 1, characterized in that, The coupling holes (3) are symmetrically distributed about the center position. The coupling hole (3) at the center position is the largest, and the size of the coupling holes (3) decreases sequentially as they extend to both ends.

5. The microwave-guided millimeter-wave ridge waveguide dual directional coupler with high coupling flatness according to claim 1, characterized in that, The cross-section of the coupling hole (3) is rectangular or circular.

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