A tray-type space power combiner

Abstract

The present invention discloses a tray-type space power synthesizer, including a cover plate and a base, a plurality of trays stacked in sequence are arranged between the cover plate and the base, each of the trays is provided with a waveguide opening on two opposite sides, each of the trays is provided with a PCB board, a radio frequency circuit is provided on the PCB board, the radio frequency circuit is connected with a slotted microstrip converter, the radio frequency circuit includes an antenna, and the length of the antenna is reduced from the tray of the outer layer to the tray of the middle layer. The present invention can effectively compensate for the uneven excitation of the tray by the waveguide transmission mode through the antenna structure of unequal length, obtain higher amplitude balance, thereby improving the synthesis efficiency of the power amplifier module, and is conducive to realizing the power synthesis of multiple chips, and realizing higher power output. The present invention can be widely used in the field of power synthesizers.

Description

Technical Field

[0001] The present invention relates to the technical field of power combiners, and in particular to a tray-type space power combiner. Background Art

[0002] Since the output power and gain of the power amplifier chip roll off as the application frequency band increases, in order to meet the millimeter wave system's demand for high output power, a power synthesizer can be used to combine the power of multiple power amplifier chips to achieve a high power level. Power synthesis technology is mainly divided into circuit synthesis and spatial synthesis. Circuit synthesis is mostly implemented in a binary tree topology. As the number of cascaded 2-way power splitter networks increases, the synthesis efficiency of the power synthesizer will continue to decrease. This is not conducive to multi-chip, high-power design. Therefore, spatial power synthesis technology, whose synthesis efficiency is independent of the number of chips, is widely used in millimeter wave power amplifier design.

[0003] The existing tray-type waveguide internal space power combiner is a power splitter antenna structure with equal length. 10 The mode excitation of each tray is uneven. The power divider antenna structure with equal length will cause the MMIC power amplifier chip on the tray near the center of the waveguide to receive more RF power than the tray outside the waveguide, especially when the MMIC power amplifier chip works in a saturated state or close to a saturated state, which will reduce the synthesis efficiency of the power amplifier module and the overall synthesis efficiency. Summary of the invention

[0004] In order to solve the above technical problems, an object of the present invention is to provide a tray-type space power combiner.

[0005] The technical solution adopted by the present invention is:

[0006] A tray-type space power synthesizer comprises a cover plate and a base, a plurality of trays stacked in sequence are arranged between the cover plate and the base, each of the trays is provided with a waveguide opening on two opposite sides, each of the trays is provided with a PCB board, a radio frequency circuit is provided on the PCB board, the radio frequency circuit is connected with a slotted microstrip converter, the radio frequency circuit comprises an antenna, and the length of the antenna is reduced from the outer tray to the middle tray.

[0007] According to some embodiments of the present invention, the radio frequency circuit further includes a microstrip matching network and an MMIC array, and the microstrip matching network is connected to the MMIC array and the antenna respectively.

[0008] According to some embodiments of the present invention, the PCB board includes a metal layer and a dielectric layer, the metal layer is arranged on the front side of the dielectric layer, the back side of the dielectric layer is installed on the tray, and the antenna is arranged on the back side of the dielectric layer.

[0009] According to some embodiments of the present invention, the antenna is in the form of a fin line.

[0010] According to some embodiments of the present invention, the slot-line microstrip converter includes a microstrip line arranged on the front side of the PCB board and a slot line arranged on the back side of the PCB board, the slot line is connected to the antenna, and a gradient transmission line symmetrical to the microstrip line is also arranged on the back side of the PCB board, and the gradient transmission line is perpendicular to the slot line.

[0011] According to some embodiments of the present invention, an inductive element is further disposed at the center of the tapered transmission line.

[0012] According to some embodiments of the present invention, the tray is provided with a plurality of openings.

[0013] According to some embodiments of the present invention, the opening is filled with absorbing material.

[0014] According to some embodiments of the present invention, a plurality of partition columns are provided on the tray.

[0015] According to some embodiments of the present invention, the sum of the thicknesses of the plurality of trays is equal to the length of the long side of the waveguide opening.

[0016] The beneficial effects of the present invention are:

[0017] The tray-type spatial power synthesizer of the present invention can effectively compensate for the uneven excitation of the tray by the waveguide transmission mode through the antenna structure of unequal length, obtain higher amplitude balance, thereby improving the synthesis efficiency of the power amplifier module, and is conducive to realizing the power synthesis of multiple chips and achieving higher power output. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a tray-type space power synthesizer of the present invention;

[0019] Figure 2 It is a structural schematic diagram of a tray in a tray-type space power combiner of the present invention;

[0020] Figure 3 It is a structural schematic diagram of the back side of a PCB board in a tray-type space power combiner of the present invention;

[0021] Figure 4 It is a structural schematic diagram of a radio frequency circuit in a tray-type space power synthesizer of the present invention. DETAILED DESCRIPTION

[0022] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0023] refer to Figure 1 and Figure 2An embodiment of the present invention provides a tray-type space power synthesizer, including a cover plate 1 and a base 2, a plurality of trays 3 stacked in sequence are arranged between the cover plate 1 and the base 2, each tray 3 is provided with a waveguide opening on two opposite sides, each tray 3 is provided with a PCB board 4, a radio frequency circuit is provided on the PCB board 4, the radio frequency circuit is connected with a slot line 51 microstrip converter 5, the radio frequency circuit includes an antenna 6, and the length of the antenna 6 is reduced from the outer tray 3 to the middle tray 3.

[0024] In the implementation of the present invention, four trays 3 are used, and the length and thickness of each tray 3 are equal. The tray 3 is made of metal. The selection of thickness needs to consider the heat dissipation capacity of the MMIC power amplifier chip. The thicker the tray, the better the heat dissipation performance. The four trays 3 in this embodiment are the first tray, the second tray, the third tray and the fourth tray from top to bottom. The antenna 6 of the first tray is equal to the antenna 6 of the fourth tray, and the antenna 6 of the second tray is equal to the antenna 6 of the third tray. The length of the antenna 6 of the first tray and the fourth tray is greater than the length of the antenna 6 of the second tray and the third tray, which is used to optimize the phenomenon of uneven excitation of each antenna 6 by the waveguide transmission mode. At the same time, the length of the antenna 6 determines the standing wave ratio of the input / output port. The length difference of the antenna 6 should be appropriately selected on the premise of achieving a good standing wave ratio of the input / output port, so as to improve the synthesis efficiency of the power amplifier module.

[0025] refer to Figure 4 In some embodiments, the radio frequency circuit further includes a microstrip matching network and an MMIC array 7, and the microstrip matching network is connected to the MMIC array 7 and the antenna 6 respectively.

[0026] In this embodiment, each MMIC array 7 includes four MMIC power amplifier chips, and the four trays 3 have a total of 16 MMIC power amplifier chips, which are mounted on the PCB board 4 .

[0027] refer to Figure 2 In some embodiments, the PCB board 4 includes a metal layer and a dielectric layer, the metal layer is arranged on the front side of the dielectric layer, the back side of the dielectric layer is installed on the tray 3, and the antenna 6 is arranged on the back side of the dielectric layer.

[0028] In this embodiment, the antenna 6 is in the form of a fin line. Among them, the antenna 6 can be a double-sided fin line, a single-sided fin line or a polar fin line. The antenna 6 in this embodiment adopts a single-sided fin line, and a single-sided fin line with a cosine arc is used. The length of the fin line part of the second tray and the third tray of the two trays 3 near the center of the waveguide is equal, and the length of the fin line part of the first tray and the fourth tray of the two trays 3 near the two sides of the waveguide is also equal. The fin line near the center of the waveguide is shorter than the single-sided fin line on both sides of the waveguide. It is used to optimize the phenomenon of uneven excitation of each fin line in the waveguide transmission mode. At the same time, the length of the fin line determines the standing wave ratio of the input / output port. The length difference of the fin line should be appropriately selected under the premise of achieving a good standing wave ratio of the input / output port. The width of the single-sided fin line toward the waveguide input / output port is equal to the narrow side width of the waveguide, and the width toward the MMIC power amplifier chip is the minimum line spacing that the PCB processing manufacturer can provide, usually 0.1~0.2mm.

[0029] refer to Figure 3 In some embodiments, the slot line 51 microstrip converter 5 includes a microstrip line arranged on the front side of the PCB board 4 and a slot line 51 arranged on the back side of the PCB board 4, the slot line 51 is connected to the antenna 6, and a gradient transmission line 52 symmetrical to the microstrip line is also arranged on the back side of the PCB board 4, and the gradient transmission line 52 is perpendicular to the slot line 51.

[0030] In this embodiment, the width of the slot line 51 is the minimum line spacing that the PCB processing manufacturer can provide. The fin line is connected to the slot line 51 with a length of one quarter of the wavelength of the slot line 51, and the gradient transmission line 52 is symmetrically placed on the back of the PCB board 4 at the connection, wherein the central axis of the gradient transmission line 52 is orthogonal to the slot line 51. Since the gradient transmission line 52 can achieve impedance matching in the shortest length by gradually changing the width of the microstrip. At the same time, since the gradient transmission line 52 and the fin line are also based on the small reflection design theory, the frequency response is high-pass. This structure is conducive to broadband design.

[0031] The two gradient transmission lines 52 are connected to two microstrip-implemented resistive one-to-two-way power divider / synthesizer. One side of the resistive one-to-two-way power divider / synthesizer is interconnected with the MMIC power amplifier chip through bonding wires, and the characteristic impedance of the microstrip line of this part is the input / output impedance of the MMIC power amplifier chip. The characteristic impedance of the microstrip line on the other side is half of the former, and the impedance matches the gradient transmission line 52. Therefore, the length of all microstrip lines of the resistive one-to-two-way power divider / synthesizer can be adjusted at will without affecting the matching. This is conducive to miniaturized design.

[0032] In some embodiments, an inductive element is further disposed at the center of the gradient transmission line 52 .

[0033] In the design of the slot line 51-microstrip converter, if impedance matching is to be achieved, the end face impedance where the microstrip intersects the slot line 51 needs to provide a sufficient imaginary part. However, the tapered transmission line 52 cannot achieve impedance matching for reactance. Therefore, it is necessary to add an inductive element at the center of the tapered transmission line 52 to achieve impedance matching at the end face.

[0034] In this embodiment, two centrally symmetrical arc-shaped open lines 53 are used at the symmetric points of the tapered transmission line 52. As a microstrip inductor, the open transmission line supplements the reactance part of the tapered transmission line 52 when used as an impedance match. The arc of the open transmission line should be as large as possible to avoid overlap with the slot line 51. This effectively avoids the interference of the open line on the propagation mode of the slot line 51. At the same time, the width of the open transmission line should be as wide as possible to avoid radiation loss caused by the end of the open transmission line.

[0035] In some embodiments, the tray 3 is provided with a plurality of openings. In this embodiment, the openings are rectangular grooves, and the depth of the grooves is intended to provide sufficient height for the packaging size of the chip and the patch component.

[0036] In some embodiments, the opening is provided with an absorbing material, which is placed at the center of the opening, and the absorbing material is as wide as the chip and as long as the opening.

[0037] In some embodiments, a plurality of partition columns are provided on the tray 3. The partition columns are used to separate the cavities in the tray 3, thereby avoiding resonance of the cavities. As many rectangular metal columns as possible can be added without affecting the circuit performance. In this embodiment, 12 partition columns are symmetrically used at each tray 3. The partition columns can be rectangular metal columns or columns of other shaped materials that can separate the cavities.

[0038] In some embodiments, the sum of the thicknesses of the plurality of trays 3 is equal to the length of the long side of the waveguide opening.

[0039] From the above content, it can be seen that the present invention can effectively compensate for the uneven excitation of the tray 3 by the waveguide transmission mode through the antenna 6 structure of unequal length, obtain higher amplitude balance, thereby improving the synthesis efficiency of the power amplifier module, and is conducive to realizing power synthesis of multiple chips, achieving higher power output.

[0040] The above is a specific description of the preferred implementation of the present invention, but the invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A tray-type space power combiner, characterized in that: It comprises a cover plate and a base, wherein a plurality of trays stacked in sequence are arranged between the cover plate and the base, each of the trays is provided with a waveguide opening on two opposite sides, each of the trays is provided with a PCB board, a radio frequency circuit is arranged on the PCB board, the radio frequency circuit is connected with a slotted microstrip converter, the radio frequency circuit comprises an antenna, and the length of the antenna is reduced from the tray of the outer layer to the tray of the middle layer; the PCB board comprises a metal layer and a dielectric layer, the metal layer is arranged on the front side of the dielectric layer, the back side of the dielectric layer is installed on the tray, and the antenna is arranged on the back side of the dielectric layer; the antenna is in the form of a fin line.

2. A tray-type space power combiner according to claim 1, characterized in that: The radio frequency circuit also includes a microstrip matching network and an MMIC array, and the microstrip matching network is connected to the MMIC array and the antenna respectively.

3. The tray-type space power combiner according to claim 1, characterized in that: The slot-line microstrip converter comprises a microstrip line arranged on the front side of the PCB board and a slot line arranged on the back side of the PCB board, wherein the slot line is connected to an antenna, and a gradient transmission line symmetrical to the microstrip line is also arranged on the back side of the PCB board, wherein the gradient transmission line is perpendicular to the slot line.

4. The tray-type space power combiner according to claim 3, characterized in that: An inductive element is also arranged at the center of the gradient transmission line.

5. The tray-type space power combiner according to claim 1, characterized in that: The tray is provided with a plurality of openings.

6. The tray-type space power combiner according to claim 5, characterized in that: The opening is provided with a wave absorbing material.

7. The tray-type space power combiner according to claim 1, characterized in that: A plurality of partition columns are arranged on the tray.

8. The tray-type space power combiner according to claim 1, characterized in that: The sum of the thicknesses of the plurality of trays is equal to the length of the long side of the waveguide opening.

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