CN215644940U

CN215644940U - Three-way power synthesizer suitable for 54MHz-88MHz wave band

Info

Publication number: CN215644940U
Application number: CN202122246643.2U
Authority: CN
Inventors: 隋强; 张光明; 张强; 王波; 王轶冬; 杨奇鑫
Original assignee: Jiangsu Deshihe Communication Technology Co ltd
Current assignee: Jiangsu Deshihe Communication Technology Co ltd
Priority date: 2021-09-16
Filing date: 2021-09-16
Publication date: 2022-01-25
Anticipated expiration: 2031-09-16

Abstract

The utility model discloses a three-way power synthesizer suitable for a 54MHz-88MHz wave band, which is formed by cascading a single section of 3dB coupler and a single section of 4.8dB coupler; the internal electromagnetic coupling of the 3dB coupler and the 4.8dB coupler is realized by coupling of a folded coupling plate with a structure shaped like a Chinese character 'ji'; and respectively inputting two paths of electric signals with equal power and 90-degree phase difference from two mutually isolated ports of the 3dB coupler for power combination, inputting the combined electric signals to the 4.8dB coupler, and carrying out secondary synthesis with a third path of electric signals to obtain a synthesized output signal.

Description

Three-way power synthesizer suitable for 54MHz-88MHz wave band

Technical Field

The utility model belongs to the field of passive devices of electronic information/radio frequency/broadcast television, and particularly relates to a three-way power synthesizer suitable for a 54MHz-88MHz waveband.

Background

In recent years, the use of three-way synthesizers with wave band of 54MHz-88MHz is more and more required, and a three-in-one power synthesizer used inside a VHF (54MHz-88MHz) transmitter is a common passive device and is used for summing and synthesizing three signals to one port for outputting, so that the function of power synthesis is completed. As shown in fig. 1, the VHF (54MHz-88MHz) three-way synthesizer is implemented by cascading 13 db coupler and 1 4.8db coupler, and the internal electromagnetic coupling between a single 3db coupler and a single 4.8db coupler is implemented by plate-shaped strip line width side coupling. Such synthesizers are generally referred to as chain synthesizers.

A single-section 3-decibel coupler can distribute one path of signal into two paths of signals with equal power, and the coupler is provided with 4 ports which are an input end, a straight-through end, a coupling end and an isolation end. For an ideal 3dB coupler, the isolation end of the coupler has no output, the output power of the direct connection end and the coupling end is half of the input power respectively, and the phase of the output signal of the direct connection end lags the phase of the output signal of the coupling end by 90 degrees. When the 3dB coupler is used as a power synthesizer, electric signals with equal power and 90-degree phase difference are input from two mutually isolated ports, the two electric signals can be synthesized and output from one port, and the effect of power synthesis is finished.

A single-section 4.8-decibel coupler can distribute one path of signals into two paths of signals with the power ratio of 2:1, and the coupler is provided with 4 ports which are respectively an input end, a straight-through end, a coupling end and an isolation end. For an ideal 4.8db coupler, the isolation port has no output, the output power of the through port and the coupling port is 2/3 and 1/3 of the input power, respectively, and the phase of the output signal of the through port lags the phase of the output signal of the coupling port by 90 °. When the 4.8dB coupler is used as a power synthesizer, electric signals with the power ratio of 2:1 and the phase difference of 90 degrees are input from two mutually isolated ports, the two electric signals can be synthesized and output from one port, and the effect of power synthesis is finished.

In order to reduce the overall volume of the VHF transmitter, the appearance, the port layout and the like of the three-way power combiner for the VHF transmitter in the 54MHz-88MHz wave band have stricter requirements. However, three-way power synthesizers for VHF transmitters in the 54MHz-88MHz band meeting the stringent requirements are rare in the market.

SUMMERY OF THE UTILITY MODEL

Utility model purpose: in order to make up the technical blank of the three-way power synthesizer for the VHF transmitter with the wave band of 54MHz-88MHz, the utility model provides the VHF (54MHz-88MHz) three-way power synthesizer, the internal coupling plates of which all adopt a folded structure in the shape of a Chinese character 'ji', and the appearance and the port spacing of the coupler can be conveniently changed by matching and adjusting the bending quantity of the Chinese character 'ji' shape and the length size of the Chinese character 'ji'.

The technical scheme is as follows: a three-way power synthesizer suitable for a 54MHz-88MHz wave band is formed by cascading a single-section 3dB coupler and a single-section 4.8dB coupler; the internal electromagnetic coupling of the 3dB coupler and the internal electromagnetic coupling of the 4.8dB coupler are realized by coupling a pair of coupling plates with the same structure; the coupling plates comprise 2 upper coupling plates with L-shaped structures, lower coupling plates with U-shaped structures and U-shaped connecting coupling plates, and the 2 upper coupling plates are respectively connected with the two sides of the opening end of the lower coupling plate through the U-shaped connecting coupling plates to form a folded inverted U-shaped structure; and respectively inputting two paths of electric signals with equal power and 90-degree phase difference from two mutually isolated ports of the 3dB coupler for power combination, inputting the combined electric signals to the 4.8dB coupler, and carrying out secondary synthesis with a third path of electric signals to obtain a synthesized output signal.

Further, the third path of electric signal is input into the 4.8db coupler through a section of coaxial transmission line with a length of one-quarter wavelength, and is secondarily synthesized with the electric signal synthesized by the 3db coupler, so as to obtain a synthesized output signal.

Further, the coaxial transmission line is of a double-layer structure.

Further, the device also comprises a first input port, a second input port, a third input port, a first load port, a second load port and an output port;

the 3 decibel coupler comprises a port 1, a port 2, a port 3 and a port 4; the port 1 is connected with the port 4 through a coupling plate, and the port 2 is connected with the port 3 through the coupling plate; the port 1 is connected with a first input port, the port 3 is connected with a second input port, the port 2 is connected with a first load port, and the port 4 is connected with a 4.8 decibel coupler and used for inputting a signal with the power of 2P to the 4.8 decibel coupler, wherein P is the power of an electric signal input by the 3 decibel coupler;

the 4.8 decibel coupler comprises a port I, a port II, a port III and a port IV; the port I is connected with the port IV through a coupling plate, and the port II is connected with the port III through the coupling plate; the port I is connected with a port 4 of the 3dB coupler, the port III is connected with a third electric signal with power P through a section of coaxial transmission line with the length of one quarter wavelength, the port II is connected with a second load port, and the port IV is connected with an output port.

Furthermore, the first input port, the second input port and the third input port are all located on the same plane and are directed to the same direction.

Further, the distance between the input ports is 3U.

Further, the electric signals input into the first input port, the second input port and the third input port are electric signals with equal power, and the phase is required to be 0 °, -90 °, and-90 °.

Further, the axis of the output port is perpendicular to the axis of the input port.

Further, the length of the coupling plate is 1056 mm.

Further, the length of the coaxial transmission line is 1056 mm.

Has the advantages that: compared with the prior art, the utility model has the following advantages:

(1) the coupling line in the VHF (54MHz-88MHz) three-way power synthesizer adopts a double-layer inverted V-shaped structure, the space between 3 input ports and the overall dimension of the whole synthesizer can be flexibly adjusted according to the requirement, so that the requirements of transmitter manufacturers on the space and the depth of the input ports are met, the requirements of the transmitter manufacturers on the space between the input ports of 133.35mm (3U) and the customized requirement that the dimension of the synthesizer in the depth direction is less than 350mm are met, and the VHF three-way power synthesizer has good application value;

(2) the coupling lines in a double-layer inverted V-shaped structure can be used for designing three paths of power combiners with other port spacing and size requirements;

(3) the reflection loss of the three-way power synthesizer in an in-band VHF (54MHz-88MHz) is more than 30 decibels, the amplitude meets 6.02 +/-0.5 decibels, the fluctuation of phase difference is within +/-8 degrees, and the isolation between input ports is more than 25 decibels;

(4) the VHF (54MHz-88MHz) three-way power synthesizer of the utility model has compact integral structure and convenient installation.

Drawings

FIG. 1 is a schematic diagram of a three-way power combiner;

FIG. 2 is a schematic view of a folded coupling plate of the present invention;

FIG. 3 is a schematic perspective view of a coupling plate and a coaxial transmission line according to the present invention;

fig. 4 is a schematic plan view of a coupling plate and a coaxial transmission line according to the present invention;

FIG. 5 is a diagram of the interior of the three-way power combiner of the present invention, FIG. 1;

FIG. 6 is a diagram of the interior of the three-way power combiner of the present invention, FIG. 2;

fig. 7 is a diagram of a three-way power combiner in accordance with the present invention.

Detailed Description

The technical solution of the present invention will be further explained with reference to the accompanying drawings.

Fig. 1 shows a schematic diagram of a three-way power synthesizer, and the VHF (54MHz-88MHz) three-way synthesizer of the present invention is cascaded by a single 3db coupler and a single 4.8db coupler, and can add and synthesize three-way signals to one port for output, thereby completing power synthesis.

The structure of the three-way power combiner of the present invention will now be further described with reference to fig. 2 to 7.

The three-way power synthesizer comprises a 3dB coupler 3dBcoupler, a 4.8dB coupler 4.8dBcoupler, a first input port in1, a second input port in2, a third input port in3, a first load port Match1, a second load port Match2 and an output port out.

The 3 decibel coupler comprises a port 1C _1, a port 2C _2, a port 3C _3 and a port 4C _ 4; the port 1C _1 and the port 3C _3 are isolated from each other, the port 2C _2 and the port 4C _4 are isolated from each other, the port 1C _1 is connected with the port 4C _4 through the folded coupling plate 1 with the inverted V-shaped structure, and the port 2C _2 is connected with the port 3C _3 through the folded coupling plate 1 with the inverted V-shaped structure; the port 1C _1 is connected to the first input port in1, the port 3C _3 is connected to the second input port in2, the port 2C _2 is connected to the first load port Match1, and the port 4C _4 is connected to the 4.8db coupler, and is configured to input a signal with power of 2P to the 4.8db coupler, where P is the power of an electrical signal input by the 3db coupler.

Wherein, the 4.8 dBCCopler of the 4.8 decibel coupler comprises a port IC _ I, a port IIC _ II, a port IIIC _ III and a port IVC _ IV; the port IC _ I is connected with the port IVC _ IV through a folded coupling plate 1 in a zigzag structure, and the port IIC _ II is connected with the port IIIC _ III through the folded coupling plate 1 in the zigzag structure; the port IC _ I is connected with a port 4C _4 of the 3dB coupler, the port IIIC _ III is connected with a third electric signal with power P through a section of coaxial transmission line 2 with the length of one quarter wavelength, the port IIC _ II is connected with a second load port Match2, and the port IVC _ IV is connected with an output port out.

The three input ports are located on the same plane, the three input ports are directed to the same direction, and the distance between the input ports is 133.35mm (3U), so that the three-way combiner can be conveniently connected with a power amplification module of the transmitter. And the phase requirements of the 3 equal power input signals are 0 deg. -90 deg. and-90 deg.. The axis of the output port is vertical to the axis of the input port, and signals are output from the side face of the synthesizer, so that the connection is convenient. The output port can adopt an EIA 15/8' specification coaxial port, and the load port is used for absorbing load. The inner conductor and the outer conductor and the coupling plate are supported and fixed through polytetrafluoroethylene rods, and the diameter of each supporting column is 10 mm.

The coupling plate 1 of the folded zigzag structure used in the present invention will now be further described with reference to fig. 2, 3 and 4.

The traditional coupling plate with the inverted-V-shaped structure is a folding mode of a plane structure, and the two-dimensional directions (length and width) of the plane are utilized, so that the external dimension and the port spacing of the whole coupler are adjusted through the number of the folding structures. However, the vertical height direction of the plane is not well utilized, and when the depth dimension requirement of the synthesizer is small and the port spacing requirement is small, the folding mode of the 'plane' structure cannot meet the design requirement. Therefore, the coupling plates of the 3dB coupler and the 4.8dB coupler used by the utility model both adopt 2 inverted-V-shaped structures which are folded at the vertical height, and the appearance and the port spacing of the couplers can be conveniently changed by matching and adjusting the bending quantity of the inverted-V-shaped structures and the length size of the inverted-V-shaped structures. In order to meet the requirements that the distance between input ports of a synthesizer is 133.35mm (3U) and the depth direction size of the synthesizer is smaller than 350mm, the coupling plate 1 comprises 2 upper-layer coupling plates 11 with an L-shaped structure, a lower-layer coupling plate 12 with a U-shaped structure and a U-shaped connecting coupling plate 13, wherein the 2 upper-layer coupling plates 11 are respectively connected with two sides of the opening end of the lower-layer coupling plate 12 through the U-shaped connecting coupling plate 13 to form a folded inverted U-shaped structure.

Through simulation, parameters of the U-shaped plate structure are optimized, the electrical indexes of the three-way power synthesizer meet the use requirements, and the three-way synthesizer occupies a depth space as little as possible after being connected with a power amplification module of a transmitter. The number of the double-layer coupling plates in the double-layer coupling plate and the cross section size of the double-layer coupling plate are reasonably adjusted, so that the requirements of transmitter manufacturers on the appearance, port layout, volume and the like of a 3-path synthesizer can be met, and the requirements on electrical indexes such as power capacity, port reflection loss, isolation and the like of the synthesizer can also be met.

The utility model will now be further described with reference to a coaxial transmission line 2 of quarter wavelength length.

The input end of the 4.8dB coupler is connected with a section of coaxial transmission line with the length of quarter wavelength and the characteristic impedance of 50 ohms, so that the phase deviation fluctuation value of the input port (third input port) of the 4.8dB coupler in 54MHz-88MHz is smaller than +/-8 degrees, and the synthesis efficiency of the three-way synthesizer is improved; the coaxial transmission line is designed as a "double layer" structure.

The three-way power synthesizer is suitable for a wave band of 54MHz-88MHz, the central frequency of the wave band of 54MHz-88MHz is 71MHz, in order to ensure that the phase difference between a coupling end and a straight-through end is 90 degrees, the length of a coupling plate is a strip line with 1/4 wavelengths, and the length of the coupling plate is about 1056 mm. The coaxial transmission line connected to the input port of the 4.8db coupler is also about 1056mm in length in the 54MHz-88MHz band.

The single-section 3-decibel coupler adopted by the utility model is simulated, and after simulation debugging, the port reflection loss and the isolation degree in a frequency band (54MHz-88MHz) are both greater than 32 decibels, the port reflection loss is both greater than 32dB, and the coupling degree is 3 +/-0.5 decibels. A single-section 4.8-decibel coupler is simulated, and after simulation debugging, the port reflection loss and the isolation degree in a frequency band (54MHz-88MHz) are both greater than 32 decibels, the port reflection loss is both greater than 32dB, and the coupling degree is 4.8 +/-0.5 decibels. The three-way power synthesizer of the utility model is debugged and optimized, the three-way power synthesizer is designed according to the optimized structure, and a prototype of the three-way power synthesizer is tested, so that the port reflection loss in a use frequency band is more than 30 decibels, the isolation degree between ports is more than 32 decibels, and the coupling degree reaches 6 +/-0.5 decibels, thereby completely meeting the use requirements of transmitter manufacturers.

Claims

1. A three-way power synthesizer suitable for a 54MHz-88MHz wave band is formed by cascading a single-section 3dB coupler and a single-section 4.8dB coupler; the method is characterized in that: the internal electromagnetic coupling of the 3dB coupler and the internal electromagnetic coupling of the 4.8dB coupler are realized by coupling a pair of coupling plates with the same structure; the coupling plates comprise 2 upper coupling plates with L-shaped structures, lower coupling plates with U-shaped structures and U-shaped connecting coupling plates, and the 2 upper coupling plates are respectively connected with the two sides of the opening end of the lower coupling plate through the U-shaped connecting coupling plates to form a folded inverted U-shaped structure; and respectively inputting two paths of electric signals with equal power and 90-degree phase difference from two mutually isolated ports of the 3dB coupler for power combination, inputting the combined electric signals to the 4.8dB coupler, and carrying out secondary synthesis with a third path of electric signals to obtain a synthesized output signal.

2. The three-way power combiner of claim 1, adapted for use in the 54MHz-88MHz band, wherein: and inputting the third path of electric signals into a 4.8-decibel coupler through a section of coaxial transmission line with the length of one quarter of wavelength, and carrying out secondary synthesis on the third path of electric signals and the electric signals synthesized by the 3-decibel coupler to obtain synthesized output signals.

3. The three-way power combiner of claim 2, wherein: the coaxial transmission line is of a double-layer structure.

4. The three-way power combiner of claim 1, adapted for use in the 54MHz-88MHz band, wherein: the load circuit also comprises a first input port, a second input port, a third input port, a first load port, a second load port and an output port;

5. The three-way power combiner of claim 4, wherein: the first input port, the second input port and the third input port are all located on the same plane and are directed to the same direction.

6. The three-way power combiner of claim 4, wherein: the distance between the input ports is 133.35 mm.

7. The three-way power combiner of claim 4, wherein: the electric signals input into the first input port, the second input port and the third input port are equal-power electric signals, and the phase requirements are 0 degrees, -90 degrees and-90 degrees.

8. The three-way power combiner of claim 5, wherein: the axis of the output port is perpendicular to the axis of the input port.

9. The three-way power combiner of claim 1, adapted for use in the 54MHz-88MHz band, wherein: the length of the coupling plate is 1056 mm.

10. The three-way power combiner of claim 2, wherein: the length of the coaxial transmission line is 1056 mm.