CN216850277U - Waveguide coaxial converter - Google Patents

Abstract

A waveguide coaxial converter comprises a waveguide, a coaxial connector and a ridge waveguide impedance transformation section, wherein one end of the waveguide is open, the other end of the waveguide is closed, a multi-stage step-shaped ridge waveguide impedance transformation section facing the interior of the waveguide is arranged in the waveguide, and the height of the ridge waveguide impedance transformation section is gradually reduced from the closed end of the waveguide to the other end of the waveguide; and a rectangular groove is formed in the first step of the ridge waveguide impedance transformation section, which is close to the closed end of the waveguide, and the opening of the groove faces the closed end of the waveguide. The utility model discloses can solve millimeter wave system feed module's miniaturization and broadband demand. Welding and additional tuning measures are not needed in the whole design and manufacturing process, the process complexity of the product is reduced, the cost of the product is reduced, and the consistency of the product is improved.

Description

Waveguide coaxial converter

Technical Field

The utility model relates to a technical field of coaxial converter of waveguide.

Background

In the millimeter wave application field, the application range of the side-fed waveguide coaxial conversion structure is limited due to the defects of large section size, multiple sensitive structure parameters and the like. The feedback type waveguide coaxial conversion structure disclosed by the prior document can realize better performance only by introducing a square coaxial transition section between the coaxial waveguide and the waveguide, and usually needs an additional tuning screw, and in addition, the coaxial inner conductor and the stepped middle ridge in the rectangular waveguide are electrically connected in a welding mode, so that the manufacturing process is increased, and the quality of welding points also provides challenges for the consistency of products.

The waveguide coaxial converter is a passive conversion device widely used in a modern microwave millimeter wave system, and is commonly interconnected with a signal between a transceiver module and an array antenna in an active phased array antenna system to generally complete the conversion function from rectangular or circular waveguide to a coaxial line. With the development of phased array radar, higher requirements are put forward on parameters such as center frequency, bandwidth and size of a waveguide coaxial converter.

At present, waveguide coaxial conversion feed modes mainly fall into two categories: side-fed and back-fed configurations.

(1) Side-feed structure: the side-fed waveguide coaxial converter is a structure widely adopted at present, but because the input port and the output port of the structure are not on the same horizontal line, the structure is not compact enough, and the cascade requirement of limited installation space is difficult to meet. In addition, in the application field of millimeter wave frequency band, due to the small caliber size of the waveguide port, the change of the relevant critical dimension of the side-fed coaxial probe is very sensitive to the influence of the conversion performance of the waveguide coaxial converter, and great challenge is brought to the processing and manufacturing process.

(2) The feedback structure: the feedback structure places the input port of the coaxial line and the output port of the waveguide on the same horizontal line. The single-ridge waveguide is a key structure of the feedback type waveguide coaxial converter, and the impedance value of the waveguide is adjusted by utilizing multi-section stepped impedance conversion of the single-ridge waveguide, so that the impedance values of the waveguide and the coaxial line are matched. Most of the back-fed waveguide coaxial switches disclosed at present adopt a contact mode, namely a coaxial line inner conductor is in contact with a middle ridge of a transition section, namely a single-ridge waveguide, and a welding process is needed to ensure the reliability of electric contact. For example, in Chinese patent 1 (CN 110739515B) and document 1, "development of millimeter wave broadband height-reducing waveguide coaxial conversion" (Toojuntan et al. solid electronics research and development, 2020,40(05): 343-; document 2, "simulation design of wideband single-ridge waveguide-coaxial converter" (wuhuan. southern farm machinery, 2021,52(11): 176-.

In summary, the coaxial connector of the side-fed coaxial waveguide converter forms an included angle of 90 ° with the waveguide, and the structure is not compact enough, which is very unfavorable for the cascade connection between systems. In addition, in the millimeter wave application field, because the waveguide size is very small, sensitive parameters such as the insertion depth and the position of the coaxial inner conductor directly determine the coaxial conversion effect of the waveguide, higher requirements are provided for the processing and manufacturing process, the cost of the product is obviously increased, and the mass production is not facilitated. For the feedback waveguide coaxial converter with the coaxial inner conductor directly contacted with the transition middle ridge, the welding process is adopted in the processing process, so that the process complexity is increased, and the consistency of the product is influenced; due to the small coupling size, the distance between the coaxial inner conductor and the middle ridge is very sensitive, which is not beneficial to mass production.

Disclosure of Invention

The utility model provides a coaxial converter of waveguide can solve millimeter wave system feed module's miniaturization and broadband demand. Welding and additional tuning measures are not needed in the whole design and manufacturing process, the process complexity of the product is reduced, the cost of the product is reduced, and the consistency of the product is improved.

A waveguide coaxial converter comprises a waveguide, a coaxial connector and a ridge waveguide impedance transformation section, wherein one end of the waveguide is open, the other end of the waveguide is closed, a multi-stage step-shaped ridge waveguide impedance transformation section facing the interior of the waveguide is arranged in the waveguide, and the height of the ridge waveguide impedance transformation section is gradually reduced from the closed end of the waveguide to the other end of the waveguide; and a rectangular groove is formed in the first step of the ridge waveguide impedance transformation section, which is close to the closed end of the waveguide, and the opening of the groove faces the closed end of the waveguide.

Preferably, the number of steps of the ridge waveguide impedance transformation section of the present invention is at least two stages from top to bottom.

Preferably, the ridge waveguide impedance transformation section of the present invention has equal step thickness.

Preferably, the utility model discloses coaxial joint's inner conductor stretches into inside the waveguide to during the first order ladder recess of ridge waveguide impedance transformation section, the first order ladder is the one-level of the superiors.

Preferably, the coaxial inner conductor of the present invention is inserted into but not in contact with the ridge waveguide impedance transformation section step.

Preferably, the first step groove depth of the ridge waveguide impedance transformation section of the present invention is 0.12-0.15 λ long and 0.001 λ away from the inner conductor edge distance.

Preferably, the distance from the ridge waveguide impedance transformation section to the two sides of the waveguide length direction is equal.

Preferably, the thickness of the ridge waveguide impedance transformation section of the present invention is 0.08-0.1 λ.

The utility model adopts the above technical scheme, compare with prior art and have following advantage:

the utility model discloses at first calculate the initial parameter value that reachs the spine in the changeover portion waveguide through the theory, then optimize the debugging with the help of commodity electromagnetism full wave simulation software and make the matching reach the optimum. Found in the research process that the key technical parameters of the utility model comprise: the height and length of the steps, the height and length of the grooves and the insertion depth of the coaxial probe are determined, and the insertion depth of the probe can influence the position of an electromagnetic wave excitation field, so that matching is influenced; the size of the ladder can change the impedance value of the ridge waveguide, so that the impedance value of the rectangular waveguide is gradually transited to be equal to the impedance value of the coaxial line.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a sectional view taken along line a-a of fig. 1.

Fig. 3 is a top view of fig. 1.

Fig. 4 is a left side view of fig. 1.

Detailed Description

Coaxial lines and waveguides are two common types of microwave transmission lines, but because the modes of electromagnetic waves transmitted by the two are different, for example, the main mode of coaxial line transmission is TEM mode, and the TE10 mode of rectangular waveguide transmission, if the two are directly connected, discontinuity is introduced into the two modes, namely structural mode and transmission mode, and impedance mismatch is caused. Therefore, a common means is to introduce a ridge waveguide as an impedance transformation section between the coaxial line and the waveguide, the main mode of ridge waveguide transmission is consistent with that of the rectangular waveguide, the middle ridge of the ridge waveguide is set to be of a step-like height, the lower end of the ridge waveguide has higher impedance and is connected with the waveguide, the lower end of the ridge waveguide has lower impedance and is electrically connected with the conductor in the coaxial line, and the step-like impedance transformation is realized by the step-like change in the height direction of the middle ridge, so that broadband matching is realized, and the technology is widely applied.

The coaxial waveguide conversion requires that the coaxial inner conductor and the waveguide middle ridge of the transition section are structurally and electrically connected, namely, in a forced feed mode, the coaxial inner conductor and the waveguide middle ridge are in physical contact regardless of welding or plug-in connection, and the coaxial waveguide conversion can be called as a contact type wave converter.

However, as the frequency of use of electromagnetic waves increases, especially to the millimeter wave frequency band, the physical dimensions of the waveguide and the coaxial line are reduced due to the shortened operating wavelength, and compared with the waveguide coaxial converter in the low frequency band, the sensitivity to the processing tolerance is greatly improved, if the contact type wave and process is still adopted, in order to ensure good electrical contact, the welding point or the plugging and unplugging process needs to be controlled, which poses a great challenge to the consistency of products, not only increases the working procedures, but also increases the processing process control cost. Therefore, the utility model provides a non-contact gets waveguide coaxial switching, structurally contactless between coaxial inner conductor and the changeover portion promptly, adopts the mode of coupling to realize the transmission of electromagnetic wave.

The technical scheme of the utility model is explained in detail with the attached drawings as follows:

as shown in fig. 1, a waveguide coaxial converter includes a waveguide 1, a coaxial connector 2, and a ridge waveguide impedance transformation section 11, where one end of the waveguide 1 is open and the other end is closed; a multi-stage stepped ridge waveguide impedance transformation section 11 facing the interior of the waveguide is arranged in the waveguide 1, and the height of the ridge waveguide impedance transformation section 11 is gradually reduced from the closed end of the waveguide 1 to the other end; and a rectangular groove is formed in the first step of the ridge waveguide impedance transformation section 11 close to the closed end of the waveguide 1, and the opening of the groove faces the closed end of the waveguide 1.

As shown in fig. 1, the number of steps of the ridge waveguide impedance transformation section of the present invention is at least two stages from top to bottom. The step thicknesses of the ridge waveguide impedance transformation sections are all equal.

As shown in fig. 1, the coaxial connector of the present invention has an inner conductor extending into the waveguide and inserted into the first step groove of the ridge waveguide impedance transformation section, wherein the first step is the uppermost layer. The coaxial inner conductor and the ridge waveguide impedance transformation section step are kept in an inserted but not contacted relative position relation.

As shown in FIG. 1, the first step groove depth of the ridge waveguide impedance transformation section of the present invention is 0.12-0.15 λ long and is 0.001 λ away from the inner conductor edge distance. The distances from the ridge waveguide impedance transformation section to the two sides of the waveguide in the length direction are equal. The thickness of the ridge waveguide impedance transformation section is 0.08-0.1 lambda.

Fig. 2, fig. 3 and fig. 4 are three views of the present invention, and the coaxial waveguide converter of the present invention includes a waveguide 1, a coaxial connector 2, and a ridge waveguide impedance transformation section 11. Wherein one end of the waveguide 1 is open and the other end is closed. The waveguide 1 is provided with a multi-stage ridge waveguide impedance transformation section 11 facing the interior of the waveguide 1, and the height of the steps of the ridge waveguide impedance transformation section 11 is gradually reduced from the closed end of the waveguide 1 to the other end; a rectangular groove is formed in one side, close to the closed end of the rectangular waveguide, of the ridge waveguide impedance transformation section 11; the inner conductor of the coaxial connector 2 extends into the waveguide 1 and is inserted into the first-stage stepped groove of the ridge waveguide impedance transformation section 11. The coaxial connector 2 probe and the ridge waveguide impedance transformation section 11 are in a relative position relationship of being inserted into but not contacted with each other in a step mode. The distance between the coaxial 2 probe and the upper and lower side walls of the recess of the ridge waveguide impedance transformation section 11 is equal. In this example, the ridge waveguide impedance transformer 11 has at least two steps, the step widths are equal, and the distances between the multi-step impedance transformer and the two side walls of the waveguide 1 are equal. The waveguide 1 may be a circular waveguide or a rectangular waveguide.

The utility model discloses at first calculate the initial parameter value that reachs spine in the changeover portion waveguide through the theory when the design, then optimize the debugging with the help of commodity electromagnetism full wave simulation software and make the matching reach the optimum. Found in the research process that the key technical parameters of the utility model comprise: the height and length of the ladder, the height and length of the groove and the insertion depth of the coaxial probe are used, and the insertion depth of the probe can influence the position of an electromagnetic wave excitation field, so that matching is influenced; the size of the ladder can change the impedance value of the ridge waveguide, so that the impedance value of the rectangular waveguide is gradually transited to be equal to the impedance value of the coaxial line. Compared with the prior art, the utility model discloses a ripples need not use any switching or welding operation with the converter, also need not the tuning structure, and to a great extent has reduced the processing preparation degree of difficulty of module, improves the uniformity of product, has reduced the manufacturing cost of product.

Claims (8)

1. A waveguide coaxial converter is characterized by comprising a waveguide, a coaxial connector and a ridge waveguide impedance transformation section, wherein one end of the waveguide is open, the other end of the waveguide is closed, a multi-stage step-shaped ridge waveguide impedance transformation section facing the interior of the waveguide is arranged in the waveguide, and the height of the ridge waveguide impedance transformation section is gradually reduced from the closed end of the waveguide to the other end of the waveguide; and a rectangular groove is formed in the first step of the ridge waveguide impedance transformation section, which is close to the closed end of the waveguide, and the opening of the groove faces the closed end of the waveguide.

2. The waveguide coaxial transformer of claim 1, wherein the ridge waveguide impedance transformation section has at least two steps from top to bottom.

3. The waveguide coaxial transformer of claim 1, wherein the ridge waveguide impedance transition sections are all of equal step thickness.

4. The waveguide coaxial transformer of claim 2, wherein the inner conductor of said coaxial connector extends into the waveguide and is inserted into the first step recess of the ridge waveguide impedance transformation section, said first step being the uppermost step.

5. The waveguide coaxial transformer of claim 4, wherein the coaxial inner conductor is in an inserted but not contacting relationship with the ridge waveguide impedance transition step.

6. A waveguide coaxial transformer according to claim 4, wherein the first step groove depth of the ridge waveguide impedance transition section is 0.12-0.15 λ apart from the inner conductor edge by 0.001 λ.

7. The waveguide coaxial transformer of claim 6, wherein the ridge waveguide impedance transition is equidistant from opposite sides of the length of the waveguide.

8. A waveguide coaxial transducer according to claim 1, wherein the ridge waveguide impedance transition has a thickness of 0.08-0.1 λ.

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