Broadband coaxial to waveguide conversion structure and microwave adapter based on quad-ridge waveguide

Abstract

The present invention provides a broadband coaxial-to-waveguide conversion structure and microwave converter based on four ridged waveguides, belonging to the field of communications technology. The structure comprises a waveguide cavity substrate, four ridged waveguides, and an insulator probe. The four ridged waveguides are symmetrically arranged in pairs on opposing waveguide walls of the waveguide cavity. The insulator probe is inserted into the waveguide cavity and positioned between the four ridged waveguides, without contacting any of them. The broadband coaxial-to-waveguide conversion structure based on four ridged waveguides provided by the present invention utilizes ridged waveguides and insulators for feed transition, completing the coaxial insulator-to-waveguide transition while ensuring the airtightness of the internal microelectronic devices using insulator transitions. This achieves broadband transition and resolves the relatively narrow bandwidth problem of insulator transitions.

Description

Technical Field

[0001] The present invention belongs to the field of communication technology, and in particular relates to a broadband coaxial to waveguide conversion structure based on a quad-ridged waveguide and a microwave adapter. Background Art

[0002] Waveguide-to-coaxial converters are widely used passive microwave switching devices and are an indispensable component in radar systems, precision guidance systems, electronic countermeasures systems, and test equipment. As the operating frequency range of electronic systems continues to expand, higher bandwidth requirements are placed on converters. Ridge waveguides offer a wider frequency range than rectangular waveguides and are more suitable for use in various broadband systems. Therefore, the research and design of ridge waveguide-to-coaxial converters are of great practical significance.

[0003] The waveguide-to-coaxial converters currently in widespread use are of the plug-in type. Waveguide-to-coaxial conversion requires ensuring the airtightness of the internal semiconductor devices. Insulator probes are generally used to achieve the transition from coaxial to waveguide. However, the bandwidth of the insulator-to-waveguide probe transition structure is relatively narrow, with a general relative bandwidth of about 10%. Using only insulator probes for transition cannot guarantee broadband applications.

[0004] The rear-fed type requires inserting the insulator probe into the metal waveguide to complete the feeding, which requires welding. Especially in a specific high-reliability environment, welding is required. The welding quality greatly affects the insertion loss and standing wave of the converter. Summary of the Invention

[0005] The embodiments of the present invention provide a broadband coaxial to waveguide conversion structure and a microwave converter based on a quad-ridged waveguide, aiming to solve the problem that the bandwidth of transition switching using an insulator probe is relatively narrow and cannot meet bandwidth applications.

[0006] To achieve the above object, the technical solution adopted by the present invention is to provide a broadband coaxial to waveguide conversion structure based on a quad-ridged waveguide, comprising:

[0007] a substrate having a waveguide cavity;

[0008] Four ridge waveguides, symmetrically arranged in pairs on opposite waveguide walls of the waveguide cavity; and

[0009] The insulator probe is inserted into the waveguide cavity and located between the four ridge waveguides.

[0010] In combination with the first aspect, in a possible implementation, the waveguide cavity is a square structure, one end of each of the four ridge waveguides is fixed on the first side wall of the waveguide cavity, and the insulator probe is inserted from the top wall of the waveguide cavity.

[0011] In combination with the first aspect, in a possible implementation manner, the insulator probe is inserted to a depth extending to between the two ridge waveguides at the bottom.

[0012] In combination with the first aspect, in a possible implementation manner, the ridge waveguide has multiple impedance transformation steps.

[0013] In combination with the first aspect, in a possible implementation manner, the height of each of the impedance transformation steps decreases gradually from the first side wall of the waveguide cavity toward the opposite third side wall.

[0014] In combination with the first aspect, in a possible implementation manner, the impedance transformation steps of the two symmetrical ridge waveguides are arranged opposite to each other.

[0015] In a second aspect, an embodiment of the present invention further provides a microwave converter having the broadband coaxial-to-waveguide conversion structure based on a quad-ridged waveguide.

[0016] The broadband coaxial to waveguide conversion structure based on quad-ridged waveguide provided by the present invention has the following advantages compared with the prior art:

[0017] (1) The insulator probe is used to complete the transition with the four-ridge waveguide in the form of a quad-ridge waveguide, and then a coaxial waveguide converter covering the full standard waveguide bandwidth is completed by gradually converting the four-ridge waveguide to the standard waveguide. The insulator and the ridge waveguide are non-contact, and the entire conversion structure only needs to insert the insulator probe. The relative bandwidth of this non-contact insulator probe inserted into the four-ridge waveguide can reach 100%, solving the problem of narrow bandwidth of the direct-insertion coaxial to waveguide converter.

[0018] (2) The entire conversion structure only requires the insertion of an insulator probe, avoiding the connection of other transfer insulators and step conversion, simplifying installation and improving production efficiency and accuracy.

[0019] (3) Non-contact means no welding is required, which makes assembly easy and does not introduce solder and aperture errors. It has high accuracy and consistency, and the use of insulators can ensure the airtightness of the product. This design can be used in various applications that require airtightness and watertightness, and is suitable for high-reliability aerospace applications.

[0020] (4) The broadband transition from the coaxial probe to the standard waveguide is completed by switching between the quad-ridged waveguide and the standard waveguide. The quad-ridged waveguide has a short step transition distance, which is shorter than that of the single-ridged waveguide and the double-ridged waveguide, thus reducing the volume and weight of the entire microwave link. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the three-dimensional structure of a broadband coaxial-to-waveguide conversion structure based on a quad-ridged waveguide provided in an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of the main structure of a broadband coaxial-to-waveguide conversion structure based on a quad-ridged waveguide provided in an embodiment of the present invention;

[0023] Description of reference numerals:

[0024] 1. Waveguide cavity; 11. First side wall; 12. Top wall; 13. Third side wall; 2. Ridge waveguide; 21. Impedance transformation ladder; 3. Insulator probe. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] Please also refer to Figure 1 and Figure 2 The broadband coaxial-to-waveguide conversion structure based on quad-ridged waveguides provided by the present invention is now described. The structure comprises a substrate having a waveguide cavity 1, four ridged waveguides 2, and an insulator probe 3. The four ridged waveguides 2 are symmetrically arranged in pairs on opposing waveguide walls of the waveguide cavity 1. The insulator probe 3 is inserted into the waveguide cavity 1 and positioned between the four ridged waveguides 2, without contacting any of them.

[0027] The broadband coaxial to waveguide conversion structure based on quad-ridged waveguide provided by the present invention has the following advantages compared with the prior art:

[0028] (1) Four ridge waveguides are used to make the insulator probe 3 complete the transition with the four ridge waveguides 2, and then a coaxial waveguide converter covering the full standard waveguide bandwidth is completed through the gradual conversion of the four ridge waveguides 2 and the standard waveguide. The insulator and the ridge waveguide 2 are non-contact, and the entire conversion structure only needs to insert the insulator probe 3. The relative bandwidth of this non-contact insulator probe 3 inserted into the four ridge waveguides 2 can reach 100%, solving the problem of narrow bandwidth of the direct-insertion coaxial to waveguide converter.

[0029] (2) The entire conversion structure only needs to insert the insulator probe 3, avoiding the connection of other transfer insulators and step conversion, simplifying the installation, and improving production efficiency and accuracy.

[0030] (3) Non-contact means no welding is required, which makes assembly easy and does not introduce solder and aperture errors. It has high accuracy and consistency, and the use of insulators can ensure the airtightness of the product. This design can be used in various applications that require airtightness and watertightness, and is suitable for high-reliability aerospace applications.

[0031] (4) The broadband transition from the coaxial probe to the standard waveguide is completed by switching between the four ridge waveguides 2 and the standard waveguide. The step transition distance of the four-ridge waveguide 2 is short, which is shorter than that of the single-ridge waveguide 2 and the double-ridge waveguide 2, reducing the volume and weight of the entire microwave link.

[0032] It's important to explain that ridged waveguides are a very important type of transmission line in microwave engineering. They typically consist of a rectangular or circular waveguide with one or more metal ridges inserted into its inner cavity. Compared to traditional waveguides, ridged waveguides are widely used due to their wide single-mode transmission bandwidth, compact size, and low characteristic impedance. The frequency range between the cutoff frequencies of the main mode and the lowest-order higher-order mode in ridged waveguides can easily reach four octaves or even wider. Compared to conventional waveguides with the same main mode cutoff frequency, they have a more compact cross-section. Their characteristic impedance lies between that of conventional rectangular waveguides (377 ohms) and coaxial and stripline cables (50 ohms). While their attenuation coefficient is several times greater than that of conventional waveguides, it is still much smaller than that of conventional coaxial cables.

[0033] In some embodiments, as Figure 1 and Figure 2 As shown, the waveguide cavity 1 is a square structure, one end of each of the four ridge waveguides 2 is fixed on the first side wall 11 of the waveguide cavity 1, and the insulator probe 3 is inserted from the top wall 12 of the waveguide cavity 1 without contacting any of the ridge waveguides 2, and the distance between the insulator probe 3 and the ridge waveguides 2 on both sides is equal.

[0034] like Figure 1 and Figure 2 In some of the embodiments shown, the insulator probe 3 is inserted to a depth extending to between the two ridge waveguides 2 at the bottom.

[0035] like Figure 1 and Figure 2 As shown, in some embodiments, the ridge waveguide 2 has multiple impedance transformation steps 21, that is, a step transition structure, which realizes the step transition between the quad-ridge waveguide 2 and the standard waveguide, and completes the broadband transition from the coaxial probe to the standard waveguide.

[0036] In some embodiments, as Figure 1 and Figure 2 As shown, the height of each impedance transformation step 21 decreases gradually from the first side wall 11 to the opposite third side wall 13 of the waveguide cavity 1 .

[0037] Optionally, the impedance transformation steps 21 of two symmetrical ridge waveguides 2 are arranged opposite to each other.

[0038] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0039] Based on the same inventive concept, an embodiment of the present application further provides a microwave converter having the broadband coaxial to waveguide conversion structure based on the quad-ridged waveguide 2 .

[0040] The microwave converter provided in the embodiment of the present application uses a ridge waveguide and an insulator for feeding transition while ensuring the airtightness of the internal microelectronic devices through an insulator transition, thereby completing the transfer from the coaxial insulator to the waveguide. While ensuring airtightness, it completes a broadband transition and solves the problem of the relatively narrow bandwidth of the insulator transition.

[0041] (2) Simplify the design so that the insulator probe does not contact the ridge waveguide metal and no welding is required, which simplifies the assembly process, reduces the manufacturing difficulty, improves the manufacturing accuracy, and improves the manufacturing consistency.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A broadband coaxial to waveguide conversion structure based on a quad-ridged waveguide, characterized in that: include: a substrate having a waveguide cavity (1); Four ridge waveguides (2) are symmetrically arranged in pairs on opposite waveguide walls of the waveguide cavity (1); as well as An insulator probe (3) is inserted into the waveguide cavity (1) and is located between the four ridge waveguides (2); the insulator and the ridge waveguide are in a non-contact manner; The waveguide cavity (1) is a square structure, one end of each of the four ridge waveguides (2) is fixed on a first side wall (11) of the waveguide cavity (1), and the insulator probe (3) is inserted from a top wall (12) of the waveguide cavity (1); The insulator probe (3) is inserted to a depth extending to between the two ridge waveguides (2) at the bottom; The ridge waveguide (2) has a plurality of impedance transformation steps (21); The height of each impedance transformation step (21) decreases gradually from the first side wall (11) of the waveguide cavity (1) toward the opposite third side wall (13); The impedance transformation steps (21) of the two symmetrical ridge waveguides (2) are arranged opposite to each other.

2. A microwave converter, characterized in that: The invention has a broadband coaxial to waveguide conversion structure based on a quad-ridged waveguide as claimed in claim 1.

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