Power combiner

Abstract

The present invention discloses a power synthesis device. The power synthesis device includes a combiner, and the combiner includes an upper cover, a power amplifier circuit board, a substrate and a bottom shell. A first shielding cavity is provided on one side of the power amplifier circuit board, and a first microstrip probe is provided in the first shielding cavity; the power amplifier circuit board is fixedly connected to the substrate; a reflection cavity is provided on one side of the bottom shell, and the side where the reflection cavity is located is opposite to the side where the first shielding cavity is located, the bottom shell is fixedly connected to the upper cover, and the bottom shell is fixedly connected to the substrate; the upper cover, the power amplifier circuit board, the substrate and the bottom shell are all in the shape of a layer plate, and the upper cover, the power amplifier circuit board, the substrate and the bottom shell are stacked in sequence from top to bottom. The power synthesis device in the embodiment of the present invention has the advantages of small size and good heat dissipation performance.

Description

Technical Field

[0001] The invention relates to the technical field of microwave devices, and in particular to a power synthesis device. Background Art

[0002] Space communications, remote sensing, navigation and other fields mainly involve microwave frequency bands. For application systems in different fields, the output power requirements range from milliwatts to several kilowatts. The power amplifier is one of the key components to meet different power requirements. However, a single power amplifier unit is usually difficult to achieve the expected goal, so power synthesis technology came into being.

[0003] At present, high-power amplifiers are mainly realized through two methods: spatial power combination and planar power combination. However, planar power combination has disadvantages such as large loss and large volume, and spatial power combination has the problem of poor heat dissipation. Summary of the invention

[0004] The main object of the present invention is to solve at least one of the above problems.

[0005] An embodiment of the present invention provides a power synthesis device. The power synthesis device includes a combiner, and the combiner includes:

[0006] Upper cover;

[0007] A power amplifier circuit board, wherein a first shielding cavity is provided on one side of the power amplifier circuit board, a first microstrip probe is provided in the first shielding cavity, and the power amplifier circuit board further integrates a power amplifier circuit and a drive circuit;

[0008] A substrate, the power amplifier circuit board is fixedly connected to the substrate;

[0009] A bottom shell, a reflection cavity is disposed on one side of the bottom shell, the side where the reflection cavity is located is opposite to the side where the first shielding cavity is located, the bottom shell is fixedly connected to the upper cover, and the bottom shell is fixedly connected to the substrate;

[0010] Wherein, the upper cover, the power amplifier circuit board, the substrate and the bottom shell are all in the shape of a layer plate, and the upper cover, the power amplifier circuit board, the substrate and the bottom shell are stacked in sequence from top to bottom;

[0011] The combiner has a waveguide output end.

[0012] According to some embodiments of the present invention, the bottom shell is connected to the base plate by threads.

[0013] According to some embodiments of the present invention, the bottom shell and the substrate are bonded and connected using conductive adhesive.

[0014] According to some embodiments of the present invention, the number of the first shielding cavities and the number of the first microstrip probes are both two, and the two first microstrip probes are respectively located inside the two first shielding cavities.

[0015] According to some embodiments of the present invention, the two first microstrip probes have the same length.

[0016] According to some embodiments of the present invention, a second shielding cavity is provided on the other side of the upper cover, a second microstrip probe is provided in the second shielding cavity, and two second microstrip probes are equal in length.

[0017] According to some embodiments of the present invention, the microstrip line of the second microstrip probe has an extended section, so that the length of the microstrip line of the second microstrip probe is greater than the length of the microstrip line of the first microstrip probe.

[0018] According to some embodiments of the present invention, the characteristic impedance of the extension section is 50 ohms.

[0019] According to some embodiments of the present invention, the power combining device further includes a filter, and the filter is in a stacked relationship with an output end of the waveguide of the combiner.

[0020] According to some embodiments of the present invention, the filter is a bandpass filter.

[0021] The power synthesis device in the embodiment of the present invention has at least the following beneficial effects: after the signal is amplified by the power amplifier circuit, the electromagnetic wave is transmitted through the microstrip probe and synthesized and output in the waveguide. Through the mutual conversion between the microstrip and the waveguide, the conversion of electromagnetic propagation from plane to space can be realized, and the advantage of good heat dissipation of planar electromagnetic propagation can be inherited, and the relevant circuits of the combiner and the driving circuit are integrated on the same PCB, thereby achieving compact size.

[0022] Additional aspects and advantages of the technical solution of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of a decomposed state of a power synthesis device in some embodiments of the present invention;

[0024] Figure 2 for Figure 1 Schematic diagram of a top view of the first shielding cavity and the first microstrip probe.

[0025] In the figure, 10 is a power synthesis device; 100 is an upper cover, 110 is a threaded connection element; 200 is a power amplifier circuit board, 210 is a first shielding cavity, 220 is a microstrip probe circuit, 221 is a first microstrip probe; 300 is a substrate; 400 is a bottom shell, and 410 is a reflection cavity. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0027] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as “upper”, “lower”, “front”, “backward”, “left” and “right” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection and a movable connection, a detachable connection and a non-detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication. "Fixed connection" includes detachable connection, non-detachable connection, and integral connection, etc.

[0029] In the present invention, terms such as "first" or "second" are used for descriptive purposes only and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features.

[0030] The technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0031] The embodiment of the present invention provides a power synthesis device 10. Figure 1 The power combining device 10 includes a combiner, which includes an upper cover 100, a power amplifier circuit board 200, a substrate 300 and a bottom shell 400.

[0032] A first shielding cavity 210 is disposed on one side of the power amplifier circuit board 200 , and a first microstrip probe 221 is disposed in the first shielding cavity 210 ; the power amplifier circuit board 200 is fixedly connected to the substrate 300 .

[0033] A reflection cavity 410 is disposed on one side of the bottom shell 400, and the side where the reflection cavity 410 is located is opposite to the side where the first shielding cavity 210 is located. The bottom shell 400 is fixedly connected to the upper cover 100, and the bottom shell 400 is fixedly connected to the substrate 300;

[0034] The upper cover 100, the power amplifier circuit board 200, the substrate 300 and the bottom shell 400 are all in the shape of a layer plate, and the upper cover 100, the power amplifier circuit board 200, the substrate 300 and the bottom shell 400 are stacked in sequence from top to bottom;

[0035] The combiner also has an output end of the waveguide.

[0036] In this embodiment, after the signal is amplified by the power amplifier circuit, the electromagnetic wave is transmitted through the microstrip probe and synthesized and output in the waveguide. Through the mutual conversion between the microstrip and the waveguide, the conversion of electromagnetic propagation from plane to space can be realized, and the advantages of good heat dissipation of planar electromagnetic propagation can be inherited, and the relevant circuits of the combiner and the driving circuit are integrated on the same PCB, thereby achieving compact size.

[0037] In some specific embodiments, see Figure 1 The bottom shell 400 is connected to the base plate 300 by threads. Specifically, a plurality of thread connection elements 110 are provided on the upper cover 100. The thread connection structure is simple and the connection is reliable, and it has the characteristics of being detachable.

[0038] In some specific embodiments, the bottom shell 400 and the substrate 300 are bonded and connected by conductive adhesive. The bonding connection also has the characteristics of simple structure and reliable connection. Furthermore, the conductive adhesive can increase the goodness of RF grounding.

[0039] In some specific embodiments, the number of the first shielding cavities 210 and the number of the first microstrip probes are both two, and the two first microstrip probes are respectively located inside the two first shielding cavities 210. The two microstrip probes form two microstrip probe circuits 220. Relatively speaking, the power division / combination topology structure with two microstrip probe circuits 220 is simpler, and the cost of the entire power combining device is lower.

[0040] In some specific embodiments, the lengths of the two first microstrip probes 221 are equal, so as to facilitate processing. Furthermore, the lengths of the two first microstrip probes 221 are not one long and the other short, which also helps to make the structure of the power synthesis device compact.

[0041] In order to obtain a higher output power, in some specific embodiments, a second shielding cavity (not shown in the figure) is provided on the other side of the upper cover 100, and a second microstrip probe (not shown in the figure) is provided in the second shielding cavity, and the lengths of the two second microstrip probes are equal. Thus, the power synthesis device has four microstrip probes, wherein the lengths of the two first microstrip probes 221 are equal, and the lengths of the two second microstrip probes are also equal.

[0042] In some specific embodiments, the microstrip line of the second microstrip probe has an extended section, so that the length of the microstrip line of the second microstrip probe is greater than the length of the microstrip line of the first microstrip probe 221. If the length of the microstrip line of the second microstrip probe is equal to the length of the microstrip line of the first microstrip probe 221, it can be calculated through the Maxwell equations that the directions generated by the left group of shielding cavities where the first microstrip probe 221 is located are the same, and the default direction can be set to 0°; the directions generated by the right group of shielding cavities where the second microstrip probe is located are also the same, and the default direction can be set to 180°. Therefore, the phase difference between the two is 180°.

[0043] Power synthesis is achieved by adding a phase compensation line (i.e., an extended section of the microstrip line) to cancel the phase difference.

[0044] In some specific embodiments, the characteristic impedance of the extension section is 50 ohms.

[0045] Microstrip line is a microwave transmission line composed of a single conductor strip supported on a dielectric substrate. It is suitable for making planar structure transmission lines for microwave integrated circuits. When the transmission line is in a traveling wave state, the ratio of the voltage and current on the line is the characteristic impedance Z0 of the transmission line. The characteristic impedance of the transmission line is determined by the structure and characteristics of the transmission line. When the transmission line is lossless, the characteristic impedance Z0 is a real number, and the characteristic impedance Z0 is independent of the operating frequency.

[0046] In microwave communications, 50 ohm characteristic impedance is commonly used as the standard, so the characteristic impedance of the microstrip line at the operating frequency is also selected to be 50 ohms to take into account both the maximum power transmission and the minimum loss requirements.

[0047] In some specific embodiments, the power synthesis device also includes a filter (not shown in the figure), and the filter is in a stacked relationship with the output end of the waveguide of the combiner. Usually, an amplifier with a frequency conversion function will generate more harmonics when realizing frequency conversion, and frequency conversion will cause leakage of the local oscillator signal. The operating frequency of a general power amplifier is relatively wide, and there is also gain in the receiving frequency band. In order to ensure the quality of communication, it is necessary to integrate a filter after the power synthesis device to suppress harmonics, leakage of local oscillator signals and gain in the receiving frequency band. To this end, the power synthesis device in the embodiment of the present invention integrates a filter to suppress harmonics, noise of local oscillator signals and noise in the receiving frequency band.

[0048] The main function of a conventional satellite communication Ku / Ka band BUC (BUC is an up-conversion power amplifier) ​​is to amplify the intermediate frequency input signal and filter it to achieve power amplification. When the intermediate frequency input frequency is 0.95GHz, a harmonic signal 0.95GHz larger than the radio frequency signal will be introduced while the radio frequency signal is frequency-converted and amplified. Usually, the suppression index requirement for harmonic signals is 60dBc, and there are also suppression requirements for the receiving frequency band. The Ku-band BUC needs to have a noise power spectrum density of no more than -151dBm / Hz in the receiving segment (frequency range 11.45GHz~12.75GHz). This means that the filter is required to have a suppressive effect on this frequency band (frequency range 11.45GHz~12.75GHz). The filter in the embodiment of the present invention has a suppressive effect on harmonics, noise of local oscillator signals, and noise in the receiving frequency band.

[0049] The filtering effect of the combiner of two microstrip probes in the Ku band is tested. In the range of 13.75 GHz to 14.5 GHz, the return loss S 11 The noise suppression of the local oscillator frequency of 13.05GHz and the noise suppression of the receiving frequency of 11.45GHz to 12.75GHz are both greater than 16dBc. Under the actual large signal condition, the harmonic index of 14.7GHz is improved by 14dB compared with the case without filter, which can meet the engineering application.

[0050] The output ends of the filter and the waveguide of the combiner are superimposed on each other (i.e., the filters are vertically superimposed in space), and the two form a stacking relationship, so that the spatial structure of the entire power synthesis device also presents a stacking relationship and is more compact, thereby further realizing the miniaturization of the power synthesis device.

[0051] In some specific embodiments, the filter is a bandpass filter. The frequency range of the filter does not exceed the range of the combiner. It is not difficult to understand that the combiner can be switched to any frequency range as needed. The use of a bandpass filter can filter harmonics and noise within a certain range.

[0052] The following text briefly describes the main assembly process of the power synthesis device 10:

[0053] S100, bonding the power amplifier circuit board with the microstrip probe to the substrate with a conductive adhesive;

[0054] S200, installing a power amplifier circuit board with a microstrip probe on a bottom shell with a reflection cavity through a threaded connection element;

[0055] S200, the PCB bottom shell of the base plate is pressed by the upper cover.

[0056] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A power synthesis device, characterized in that: The power synthesis device comprises a combiner, and the combiner comprises: Upper cover; A power amplifier circuit board, wherein a first shielding cavity is provided on one side of the power amplifier circuit board, a first microstrip probe is provided in the first shielding cavity, and the power amplifier circuit board further integrates a power amplifier circuit and a drive circuit; A substrate, the power amplifier circuit board is fixedly connected to the substrate; A bottom shell, a reflection cavity is disposed on one side of the bottom shell, the side where the reflection cavity is located is opposite to the side where the first shielding cavity is located, the bottom shell is fixedly connected to the upper cover, and the bottom shell is fixedly connected to the substrate; Wherein, the upper cover, the power amplifier circuit board, the substrate and the bottom shell are all in the shape of a layer plate, and the upper cover, the power amplifier circuit board, the substrate and the bottom shell are stacked in sequence from top to bottom; The combiner has an output end of a waveguide; The number of the first shielding cavities and the number of the first microstrip probes are both two, and the two first microstrip probes are respectively located inside the two first shielding cavities; A second shielding cavity is provided on the other side of the upper cover, a second microstrip probe is provided in the second shielding cavity, and a microstrip line of the second microstrip probe has an extended section, so that the length of the microstrip line of the second microstrip probe is greater than the length of the microstrip line of the first microstrip probe; The power combining device further comprises a filter, and the filter is in a stacked relationship with the output end of the waveguide of the combiner.

2. The power synthesis device according to claim 1, characterized in that: The bottom shell is connected to the base plate by threads.

3. The power synthesis device according to claim 1, characterized in that: The bottom shell and the substrate are bonded and connected by using conductive adhesive.

4. The power synthesis device according to claim 1, characterized in that: The two first microstrip probes have the same length.

5. The power synthesis device according to claim 1, characterized in that: The two second microstrip probes have the same length.

6. The power synthesis device according to claim 1, characterized in that: The characteristic impedance of the extension section is 50 ohms.

7. The power synthesis device according to claim 1, characterized in that: The filter is a bandpass filter.

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