CN107134620B - A K-band waveguide microstrip transition device - Google Patents

Abstract

The invention discloses a K-waveband waveguide microstrip transition device, which solves the technical problems of inconvenient assembly and disassembly, poor sealing performance and large electromagnetic wave loss of the waveguide microstrip transition device in the prior art. The K-waveband waveguide microstrip transition device comprises an upper transition unit and a lower transition unit, wherein the upper transition unit and the lower transition unit can be combined together, an input waveguide port, a microstrip line cavity and an output waveguide port are arranged in the upper transition unit and the lower transition unit, two ends of the microstrip line cavity are respectively communicated with the input waveguide port and the output waveguide port, and a microstrip probe transition circuit is arranged in the microstrip line cavity. The invention has the advantages of low insertion loss, high return loss, wide frequency band, compact structure, good sealing property, low cost, small size, easy processing and the like.

Description

A K-band waveguide microstrip transition device

technical field

The invention relates to a waveguide microstrip transition device, in particular to a K-band waveguide microstrip transition device.

Background technique

With the development of MMIC (Millimeter Wave Monolithic Microwave Integrated Circuit) device level and MMCM (Microwave Multi-Chip Component) assembly technology, the circuit system is gradually developing towards full-plane integration. Components such as antennas still use waveguide transmission, so the transition technology from planar circuit to waveguide has become one of the key technologies for system implementation, and has been widely studied. The main purpose of the research is to find a low-cost, low-loss, Broadband transition structure for easy processing.

At present, the transition structures between rectangular waveguides and microstrips and suspended microstrips mainly include stepped ridge waveguide transitions, pair-ridge fin line transitions, and coupled probe transitions. All of these transition structures can obtain good transition effects within a bandwidth of 10% to 20%. Among them, the transition processing of the ridge waveguide is complicated, and the assembly tolerance is strict. The contact point between the ridge and the microstrip circuit has a great influence on the performance of the entire transition circuit. Too loose will affect the circuit performance, and too tight will damage the microstrip circuit. Repeatable Poor performance and inconvenient disassembly. Due to the various modes of the fin line in the transition to the ridge fin line, it is difficult to suppress all unwanted feedback, and the input and output fin lines provide a purely reactive source impedance or load impedance at the cutoff frequency, which will put the active device in an undesired state. In the stable region, self-excited oscillation is prone to occur. The common waveguide microstrip probe and the entire microstrip circuit are fabricated on an integrated circuit, and the sealing performance of this transition method is poor due to the opening on the sidewall of the waveguide to insert the probe.

SUMMARY OF THE INVENTION

In view of the above problems existing in the prior art, the present invention provides a K-band waveguide microstrip transition device, which is provided with upper and lower transition units that can be combined together, and the upper and lower transition units are processed with input waveguide ports, microstrips The strip line cavity and the output waveguide port, the two ends of the microstrip line cavity are respectively connected with the input waveguide port and the output waveguide port, the microstrip line cavity is provided with a microstrip probe transition circuit, and the upper and lower transition units are combined to form a complete Transition device.

In order to achieve the above object, the technical scheme of the present invention is achieved in this way:

The present invention provides a K-band waveguide microstrip transition device, comprising an upper transition unit and a lower transition unit, the upper transition unit and the lower transition unit can be combined together, and an input is provided in both the upper transition unit and the lower transition unit A waveguide port, a microstrip line cavity and an output waveguide port, two ends of the microstrip line cavity are respectively communicated with the input waveguide port and the output waveguide port, and a microstrip probe transition circuit is arranged in the microstrip line cavity.

Further, the microstrip probe transition circuit includes a dielectric substrate on which a microstrip line is arranged, and probes are connected to the left and right ends of the microstrip line, and the probe and the microstrip line are connected between the probe and the microstrip line. A high-resistance line is connected between the two ends, and ground terminals are provided at the left and right ends of the dielectric substrate.

Further, the microstrip probe transition circuit is fixed in the lower transition unit by bonding or welding, the probe at the left end of the microstrip line is suspended in the input waveguide port, and the probe at the right end of the microstrip line is suspended in the input waveguide port. suspended in the output waveguide port.

Further, the opening directions of the input waveguide port and the output waveguide port are opposite, and the openings are respectively located on the front and rear sides of the upper transition unit and the lower transition unit; the input waveguide port and the output waveguide port are parallel and both are perpendicular to the microstrip line. cavity.

Further, the upper transition unit is provided with an upper input waveguide port, an upper microstrip line cavity and an upper output waveguide port, and the lower transition unit is provided with a lower input waveguide port, a lower microstrip line cavity and a lower output waveguide port, The upper and lower input waveguide ports are combined, the upper and lower microstrip line cavities are combined, and the upper and lower output waveguide ports are combined.

Further, the size of the upper input waveguide port, the upper output waveguide port, the lower input waveguide port, and the lower output waveguide port is half of the WR-41 standard waveguide port, and the shapes of the upper microstrip line cavity and the lower microstrip line cavity are It is adapted to the shape of the transition circuit of the microstrip probe.

Further, the upper transition unit and the lower transition unit are combined together by bolts or locating pins, the edge of the combined surface of the upper transition unit and the lower transition unit is provided with a stop, and the upper transition unit and the lower transition unit are combined. Afterwards, laser sealing is performed on the edge of the combined surface.

Further, the passband frequency range of the K-band waveguide-microstrip transition device is 18GHz-24GHz, and the return loss is less than -20dB.

Further, the material of the dielectric substrate is PCB or ceramic, and the material of the probe, the high-resistance line, the microstrip line and the ground terminal is gold or copper.

Further, the material of the upper transition unit and the lower transition unit is aluminum or copper, and the surfaces are gold-plated, or at least gold-plated on the inner surfaces of the input waveguide port, the microstrip line cavity and the output waveguide port.

The K-band waveguide-microstrip transition device with the above structure has the following advantages:

The invention adopts separate processing of the upper and lower transition units, and then combines them to form a complete transition device, which has the advantages of compact structure, good sealing performance, low cost, small size, easy processing and the like.

The invention has the advantages of low insertion loss, high return loss and wide frequency band. The frequency range of the passband of the invention is 18GHz-24GHz, the return loss is less than -20dB, and the insertion loss is less than 1dB.

Compared with similar waveguide microstrip transition devices of the same size, the invention has wider bandwidth, better sealing, and the product qualification rate is higher than 90%, and is suitable for mass production.

Description of drawings

Fig. 1 is the exploded view of K-band waveguide microstrip transition device of the present invention;

Fig. 2 is the bottom view of the upper transition unit in the K-band waveguide microstrip transition device of the present invention;

Fig. 3 is the top view of the lower transition unit in the K-band waveguide microstrip transition device of the present invention;

Fig. 4 is the top view of the microstrip probe in the K-band waveguide microstrip transition device of the present invention;

FIG. 5 is an electrical characteristic curve diagram of the K-band waveguide-microstrip transition device of the present invention.

In the figure: 1. Upper transition unit; 2. Lower transition unit; 3. Microstrip probe transition circuit; 4. Upper input waveguide port; 5. Upper high resistance cavity; 6. Upper microstrip line cavity; 7. Upper output Waveguide port; 8. Fixing bolt; 9. Upper stop port; 10. Lower input waveguide port; 11. Lower high resistance cavity; 12. Lower microstrip line cavity; 13. Microstrip line fixed end; 14. Lower output waveguide port ; 15. Fixing bolt hole; 16. Bottom stop; 17. Dielectric substrate; 18. Probe; 19. High resistance line; 20. Microstrip line; 21. Ground terminal.

Detailed ways

The design concept of the present invention is:

Aiming at the defects of the waveguide-microstrip transition device in the prior art, the present invention provides a K-band waveguide-microstrip transition device, which is provided with upper and lower transition units that can be combined together. The input waveguide port, the microstrip line cavity and the output waveguide port, the two ends of the microstrip line cavity are respectively connected with the input waveguide port and the output waveguide port, the microstrip line cavity is provided with a microstrip probe transition circuit, and the upper and lower transition units are combined Then a complete transition device is formed. The invention has the advantages of compact structure, good sealing performance, low cost, small size, easy processing and the like by adopting the structure of separate processing and recombination.

In order to make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

Example 1

FIG. 1, FIG. 2, FIG. 3, and FIG. 4 show Embodiment 1 of the present invention. In this embodiment, a K-band waveguide microstrip transition device includes an upper transition unit 1 and a lower transition unit 2. The upper transition unit The unit 1 and the lower transition unit 2 can be combined together. Both the upper transition unit 1 and the lower transition unit 2 are provided with an input waveguide port, a microstrip line cavity and an output waveguide port. The two ends of the microstrip line cavity are respectively connected to the input waveguide port and the output waveguide port. The output waveguide port is connected, and a microstrip probe transition circuit 3 is arranged in the microstrip line cavity.

The transition device is designed into two parts that can be combined, so that the input waveguide port, the microstrip line cavity and the output waveguide port can be respectively processed in the upper and lower parts, and then combined to form a complete transition device. For example, the upper transition unit 1 and the lower transition unit 2 can be processed by a high-precision CNC machining center, and then combined.

As shown in FIG. 4 , the microstrip probe transition circuit 3 includes a dielectric substrate 17 on which a microstrip line 20 is arranged, and the left and right ends of the microstrip line 20 are connected with probes 18 , the probes 18 and the microstrip line A high-resistance line 19 is connected between 20 , and ground terminals 21 are provided at the left and right ends of the dielectric substrate 17 .

The dielectric substrate 17 is wide in the middle and narrow at both ends. The width of the high resistance line 19 is smaller than the width of the microstrip line 20 and the probe 18 .

The microstrip probe transition circuit 3 is a symmetrical structure at the left and right ends, and can be placed in the microstrip line cavity without distinguishing the directions.

The microstrip probe transition circuit 3 is bonded (bonded with conductive glue) or fixed in the lower transition unit 2 by welding, the probe 18 at the left end of the microstrip line 20 is suspended in the input waveguide port, and the probe 18 at the right end of the microstrip line 20 is suspended in the input waveguide port. Suspended in the output waveguide port. The electromagnetic wave signal in the input waveguide port is coupled through the probe 18 at the left end and the microstrip line 20, and then is transmitted through the probe 18 at the right end, and is output from the output waveguide port. The output waveguide port is externally connected to a circuit that needs to input the converted electromagnetic wave.

As shown in FIG. 1 , the opening directions of the input waveguide port and the output waveguide port are opposite, and the openings are located on the front and rear sides of the upper transition unit 1 and the lower transition unit 2 respectively. The input waveguide port and the output waveguide port are parallel, and both are perpendicular to the microstrip line cavity.

The openings of the input waveguide port and the output waveguide port are opposite to each other, which is convenient for the input waveguide port to be connected to the waveguide, and the output waveguide port to be connected to the circuit.

As shown in FIG. 2 and FIG. 3 , the upper transition unit 1 is provided with an upper input waveguide port 4 , an upper microstrip line cavity 6 and an upper output waveguide port 7 , and the lower transition unit 2 is provided with a lower input waveguide port 10 , a lower microstrip line cavity 6 and an upper output waveguide port 7 . Stripline cavity 12 and lower output waveguide port 14 .

The upper input waveguide port 4 and the lower input waveguide port 10 are combined to form a complete input waveguide port, the upper microstrip line cavity 6 and the lower microstrip line cavity 12 are combined to form a complete microstrip line cavity, and the upper output waveguide port 7 and the lower output waveguide port 14 are combined to form a complete output waveguide port.

Since the microstrip probe transition circuit 3 is fixed in the lower transition unit 2 by bonding or welding, both ends of the lower microstrip line cavity 12 are also provided with a lower high resistance cavity 11 and a microstrip line fixed end 13, and these structures are all groove-shaped structure, the groove depth is adapted to the thickness of the microstrip probe transition circuit 3 . In the upper transition unit 1, only the upper microstrip line cavity 6 and the upper high-resistance cavity 5 at both ends need to be provided.

The ground terminals 21 at the left and right ends of the microstrip probe transition circuit 3 are in contact with the lower transition unit 2 to realize grounding. The ground terminal 21 is fixed at the fixed end 13 of the microstrip line, and can also ensure that the part suspended in the waveguide port will not be bent.

The upper input waveguide port 4, the upper output waveguide port 7, the lower input waveguide port 10, and the lower output waveguide port 14 are half the size of the WR-41 standard waveguide port, and the WR-41 standard waveguide port is formed after combination. The shapes of the upper microstrip line cavity 6 , the upper high resistance cavity 5 , the lower microstrip line cavity 12 , the lower high resistance cavity 11 , and the microstrip line fixed end 13 are adapted to the shape of the microstrip probe transition circuit 3 .

The upper transition unit 1 and the lower transition unit 2 are combined by bolts. As shown in Figures 2 and 3, the upper transition unit 1 is provided with fixing bolts 8, the lower transition unit 2 is provided with fixing bolt holes 15, and the fixing bolts 8 After being inserted into the fixing bolt hole 15, a nut is fastened to the end of the fixing bolt 8.

The upper transition unit 1 and the lower transition unit 2 can also be provided with fixing bolt holes, the fixing bolt holes on the upper transition unit 1 are countersunk holes, and the fixing bolt holes on the lower transition unit 2 are threaded, and then insert the countersunk head. Tighten the bolts.

Alternatively, the upper transition unit 1 may be provided with a positioning pin, and the lower transition unit 2 may be provided with a positioning hole, and the positioning pin may be inserted into the positioning hole to realize the combination of the upper transition unit 1 and the lower transition unit 2 .

As shown in FIG. 1 , the edge of the combined surface of the upper transition unit 1 and the lower transition unit 2 is provided with a notch. After the combination of the upper transition unit 1 and the lower transition unit 2, the edge of the combined surface is laser-sealed. The upper transition unit 1 has an upper stop 9, and the lower transition unit 2 has a lower stop 16. The "stop + laser sealing and welding" structure can make the combination of the upper transition unit 1 and the lower transition unit 2 compact in structure and good sealing.

The passband frequency range of the K-band waveguide microstrip transition device is 18GHz-24GHz, the return loss is less than -20dB, and the insertion loss is less than 1dB. As shown in Figure 5, S11 represents return loss, and S21 represents insertion loss.

The material of the dielectric substrate 17 is PCB or ceramic, and the material of the probe 18 , the high-resistance line 19 , the microstrip line 20 and the ground terminal 21 is gold or copper.

The upper transition unit 1 and the lower transition unit 2 are made of aluminum or copper, with gold plating on the surface, or at least gold plating on the inner surfaces of the input waveguide port, the microstrip line cavity and the output waveguide port.

Example 2

The structure of the K-band waveguide-microstrip transition device in this embodiment is the same as that in Embodiment 1. In this embodiment, specific design reference dimensions are provided for the K-band waveguide-microstrip transition device, as shown in Figures 2, 3, and 4. The size of the upper input waveguide port 4, the lower input waveguide port 10, the upper output waveguide port 7 and the lower output waveguide port 14 is 13.7mm*4.32mm*5.334mm; the size of the upper high resistance cavity 5 is 1.6mm* 1.4mm*1mm, the chamfering radius is 1mm; the size of the upper microstrip line cavity 6 is 30mm*2.9mm*3.1mm; the radius of the fixing bolt 8 is 0.5mm and the height is 4mm; the size of the upper stop 9 is 1mm wide and 3mm high; The size of the lower high resistance cavity 11 is 1.6mm*1.4mm*0.254mm; the size of the lower microstrip line 12 is 30mm*2.9mm*0.254mm; the size of the fixed end 13 of the strip line is 4mm*1.6mm*0.254mm, and the chamfering radius is 1mm; fixed bolt hole 15 with radius of 0.5mm and depth of 3.5mm; bottom stop 16 with a width of 2mm and a depth of 3mm; dielectric substrate 17 material ROGES5880 with a thickness of 0.254mm; probe 18 with a size of 2.5mm*0.5mm; high resistance wire The size of 19 is 1.4mm*0.3mm, and the material is copper; the size of the microstrip line 20 is 30mm*0.7mm, and the material is copper; the size of the ground terminal 21 is 4mm*1.6mm, the material is copper, and the chamfering radius is 1mm; The needle 3 is glued or welded in the lower transition structure; the upper stop 9 and the lower stop 16 are assembled with each other; the fixing bolt 8 and the fixing bolt hole 15 are assembled with each other; the upper transition structure 1 and the lower transition structure 2 are assembled with laser sealing welding to ensure its tightness. The signal is input from the input end, and is introduced into the microstrip line through the spatial coupling of the microstrip probe to realize the transition from the waveguide to the planar circuit.

In the K-band waveguide microstrip probe transition device in this embodiment, the performance curve of the obtained antenna is shown in Figure 5, the passband frequency range is 18GHz-24GHz, the return loss is less than -20dB, and the insertion loss is less than 1dB. It shows that the waveguide microstrip probe transition device has excellent performance.

Example 3

The structure of the K-band waveguide-microstrip transition device in this embodiment is the same as that in Embodiment 1. In this embodiment, specific design reference dimensions are provided for the K-band waveguide-microstrip transition device, as shown in Figures 2, 3, and 4. The size of the upper input waveguide port 4, the lower input waveguide port 10, the upper output waveguide port 7 and the lower output waveguide port 14 is 13.7mm*4.32mm*5.334mm; the size of the upper high resistance cavity 5 is 1.6mm* 1.4mm*1mm, the chamfering radius is 1mm; the size of the upper microstrip line cavity 6 is 30mm*2.9mm*3.1mm; the radius of the fixing bolt 8 is 0.5mm, the height is 4mm, the size of the upper stop 9 is 1mm wide and 3mm high; The size of the lower high resistance cavity 11 is 1.6mm*1.4mm*0.254mm; the size of the lower microstrip line 12 is 30mm*2.9mm*0.254mm; the size of the fixed end 13 of the strip line is 4mm*1.6mm*0.254mm, and the chamfering radius is 1mm; the fixing bolt hole 15 has a radius of 0.5mm and a depth of 3.5mm; the bottom stop 16 is 2mm wide and 3mm deep; the dielectric substrate 17 is made of alumina ceramic; the thickness is 0.254mm; the size of the probe 18 is 2mm*0.3mm; The size of the resistance line 19 is 1.4mm*0.2mm, and the material is gold; the size of the microstrip line 20 is 30mm*0.25mm, and the material is gold; the size of the ground terminal 21 is 4mm*1.6mm, the material is gold, and the chamfering radius is 1mm; The tape probe 3 is glued or welded in the lower transition structure; the upper stop 9 and the lower stop 16 are assembled with each other; the fixing bolt 8 and the fixing bolt hole 15 are assembled with each other; the upper transition structure 1 and the lower transition structure 2 are assembled with laser sealing. Welding ensures its tightness. The signal is input from the input end, and is introduced into the microstrip line through the spatial coupling of the microstrip probe to realize the transition from the waveguide to the planar circuit.

In the K-band waveguide microstrip probe transition device in this embodiment, the performance curve of the obtained antenna is shown in Figure 5, the passband frequency range is 18GHz-24GHz, the return loss is less than -20dB, and the insertion loss is less than 1dB. It shows that the waveguide microstrip probe transition device has excellent performance.

The above are only specific embodiments of the present invention, and those skilled in the art can make other improvements or modifications on the basis of the above embodiments under the above teachings of the present invention. Those skilled in the art should understand that the above-mentioned specific description is only for better explaining the purpose of the present invention, and the protection scope of the present invention should be based on the protection scope of the claims.

Claims (9)

1. A K-waveband waveguide microstrip transition device is characterized by comprising an upper transition unit and a lower transition unit, wherein the upper transition unit and the lower transition unit can be combined together, the upper transition unit and the lower transition unit are respectively provided with an input waveguide port, a microstrip line cavity and an output waveguide port, the input waveguide ports of the upper transition unit and the lower transition unit are combined together to form the same input waveguide port, the output waveguide ports of the upper transition unit and the lower transition unit are combined together to form the same output waveguide port, two ends of the microstrip line cavity are respectively communicated with the input waveguide port and the output waveguide port, and a microstrip probe transition circuit is arranged in the microstrip line cavity;

the lower transition unit is provided with a lower input waveguide port, a lower microstrip line cavity and a lower output waveguide port, the two ends of the lower microstrip line cavity are also provided with a lower high-resistance cavity and a microstrip line fixed end, the lower high-resistance cavity and the microstrip line fixed end are both of groove-shaped structures, and the groove depth of each groove-shaped structure is matched with the thickness of the microstrip probe transition circuit;

the upper transition unit and the lower transition unit are combined together through bolts or positioning pins, the edges of the combined surfaces of the upper transition unit and the lower transition unit are provided with rabbets, and the edges of the combined surfaces are subjected to laser sealing welding after the upper transition unit and the lower transition unit are combined.

2. The K-band waveguide microstrip transition device according to claim 1, wherein the microstrip probe transition circuit comprises a dielectric substrate, the dielectric substrate is provided with a microstrip line, the microstrip line is connected with probes at both left and right ends, a high-impedance line is connected between the probe and the microstrip line, and the dielectric substrate is provided with a ground terminal at both left and right ends.

3. The K-band waveguide microstrip transition device according to claim 2, wherein the microstrip probe transition circuit is fixed in the lower transition unit by bonding or welding, the probe at the left end of the microstrip line is suspended in the input waveguide port, and the probe at the right end of the microstrip line is suspended in the output waveguide port.

4. The K-band waveguide microstrip transition device of claim 1 wherein the input and output waveguide ports have opposite openings, the openings being located on the front and rear sides of the upper and lower transition units, respectively; the input waveguide port and the output waveguide port are parallel and are perpendicular to the microstrip line cavity.

5. The K-band waveguide microstrip transition device according to claim 1 wherein the upper transition unit has an upper input waveguide port, an upper microstrip line cavity and an upper output waveguide port, the upper and lower input waveguide ports are combined, the upper and lower microstrip line cavities are combined, and the upper and lower output waveguide ports are combined.

6. The K-band waveguide microstrip transition device according to claim 5 wherein the size of the upper input waveguide port, the upper output waveguide port, the lower input waveguide port, and the lower output waveguide port is half of the size of the WR-41 standard waveguide port, and the shape of the upper microstrip line cavity and the lower microstrip line cavity is adapted to the shape of the microstrip probe transition circuit.

7. The K-band waveguide microstrip transition device of claim 1 wherein the K-band waveguide microstrip transition device has a passband frequency range of 18GHz-24GHz, a return loss of less than-20 dB, and an insertion loss of less than 1 dB.

8. The K-band waveguide microstrip transition device according to claim 2, wherein the dielectric substrate is made of PCB or ceramic, and the probe, the high-resistance line, the microstrip line and the ground terminal are made of gold or copper.

9. The K-band waveguide microstrip transition device according to claim 1, wherein the upper transition unit and the lower transition unit are made of aluminum or copper, and are plated with gold on the surface, or at least on the inner surfaces of the input waveguide port, the microstrip line cavity and the output waveguide port.

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