A radio frequency power amplification device for transmitting video in a self-organizing network

Abstract

The present invention relates to a radio frequency power amplifier device for transmitting video in a self-organizing network, and belongs to the technical field of supporting devices for self-organizing network equipment. It includes a self-organizing network transmission module and a radio frequency power amplifier device, and the radio frequency power amplifier device is composed of a power conversion and power amplifier control circuit, an RF power electronic switch circuit, a power drive module circuit and a device housing; the radio frequency power amplifier device is connected to an LNA low noise amplifier box through the device housing; the working frequency band is 640-670MHz, the transmitting and receiving channels are combined into one, the two-stage power tube of the transmitting channel is linearly amplified, and the high-power radio frequency electronic switch outputs, and the receiving channel is cascaded by the radio frequency electronic switch receiving channel. It realizes high-power long-distance wireless video transmission, fast transmission start-up time, over-current, over-temperature, open-short circuit protection, alarm function, high harmonic and clutter suppression, low production cost, convenient replacement, and solves the problems of low power output in the prior art, short wireless video transmission distance, excessive power output, easy to burn the power amplifier, and unsuitable for small-scale vehicle formation information communication.

Description

Technical Field

[0001] The invention relates to a radio frequency power amplifying device for transmitting video in a self-organizing network, belonging to the technical field of supporting components for self-organizing network equipment. Background Art

[0002] Wireless ad hoc network equipment uses mature QPSK, BPSK, 16QAM and 64QAM adaptive carrier modulation technology, and can temporarily, dynamically and quickly build a wireless IP network without relying on any basic communication facilities. It has self-organization, self-recovery, high anti-destruction and strong anti-multipath fading capabilities, and supports multi-hop transmission of many media services such as data, voice and video. Therefore, it is deeply favored by military and civilian consumers. It is not only widely used in command vehicle communication and single-soldier backpack communication, but also provides a reliable and stable information communication platform for interconnection between small-scale vehicle formations performing emergency rescue and other special tasks; however, the existing ad hoc network equipment has the problems of low power output, short wireless video transmission distance, low practicality, and difficulty in meeting the military and civilian dual-use of information communication for information communication between small-scale vehicle formations in a certain area; therefore, it is very necessary to develop a radio frequency power amplifier device for ad hoc network transmission video with large power output, long wireless video transmission distance, substantial improvement of communication quality, meeting the information communication requirements between small-scale vehicle formations in a certain area, suitable for military and civilian dual-use, and greatly enhanced practicality. Summary of the invention

[0003] The purpose of the present invention is to provide a radio frequency power amplifier device for self-organizing network transmission video, which can realize high-power and long-distance wireless video transmission through a self-organizing network transmission module plus a radio frequency power amplifier device mode, with a long wireless video transmission distance, high communication rate, simple interface, over-current, over-temperature, open-short circuit protection, alarm function, high harmonic and clutter suppression, low production cost, convenient operation, and is suitable for information communication between small-scale vehicle formations. The present invention solves the problems of low power output, short wireless video transmission distance, low practicality, and unsuitability for information communication between small-scale vehicle formations in the existing self-organizing network transmission module.

[0004] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0005] A radio frequency power amplification device for transmitting video in an ad hoc network comprises an ad hoc network transmission module, a radio frequency power amplifier device, an LNA low noise amplifier box and a cavity filter, wherein the ad hoc network transmission module comprises a main video processing chip, an auxiliary video processing chip, frequency synthesis and up / down frequency conversion processing, a radio frequency switch, etc.; the wired data signal received by the RJ45 network port terminal and the wireless signal received by the 2.4GHz antenna are sent to the main video processing chip for combination processing, the combined data are sent to the auxiliary video chip for data processing and digital-to-analog conversion to generate an analog radio frequency signal output, and the radio frequency signal is sent to the radio frequency power amplifier device through BPF bandpass filtering, frequency synthesis down frequency conversion processing, power amplifier filtering and radio frequency switch; the signal received by the radio frequency power amplifier device is converted by the radio frequency switch, broadcast to the frequency synthesis up frequency conversion radio frequency signal through low noise, and then sent to the auxiliary video processing chip after BPF bandpass filtering, the data signal after analog-to-digital conversion processing is finally sent to the main video processing chip for exchange and forwarding processing, the wired data is sent to the RJ45 network port terminal, and the wireless signal is transmitted through the 2.4GHz antenna to complete the ad hoc network video transmission communication;

[0006] The invention is characterized in that: the receiving and transmitting control signal output end of the main video processing chip is connected to the receiving and transmitting control signal TX input pin of the radio frequency power amplifier device through a wire, and the radio frequency power amplifier device is composed of a power conversion and power amplifier control circuit, an RF power electronic switch circuit, a power drive module circuit and a device housing; the radio frequency power amplifier device is connected to an LNA low noise amplifier box through a socket of the device housing; the power conversion and power amplifier control circuit is composed of a micro single chip microcomputer, a transmission control circuit, a logarithmic forward detection circuit, a logarithmic reverse detection circuit, an overcurrent detection circuit, an overtemperature detection circuit, a PTT conversion circuit, a power amplifier alarm circuit and a power supply voltage stabilization circuit; the RF power electronic switch circuit is composed of a high-power radio frequency electronic switch, a drive controller, a low-power electronic switch, an LC low-pass filter circuit and a circulator; the power drive module circuit is composed of a PA power amplifier circuit, a baseband receiving and transmitting electronic switch and a low-power electronic switch; the device housing is composed of a shell and a heat sink, and the circuit boards of the power conversion and power amplifier control circuit, the RF power electronic switch circuit and the power drive module circuit are respectively mounted on the heat sink and sealed and shielded by the shell.

[0007] The micro single chip microcomputer of the power conversion and power amplifier control circuit is used for four-way AD detection and comparison judgment output control; the transmission control circuit is composed of two field effect tubes U3 and U4 in cascade, and the alarm control output signal ALARM and RX_PTT jointly control the start-up of the transmission control circuit; the logarithmic forward detection circuit and the logarithmic reverse detection circuit are used for the forward and reverse detection of the transmission power standing wave, which is converted into a DC voltage by the logarithmic detector and sent to the micro single chip microcomputer for analog-to-digital conversion and comparison processing, and the field effect tubes U3 and U4 cascade are controlled to be on and off, and then together with the RX_PTT signal, the output power of the PA power amplifier circuit in the power driving module circuit is controlled to be on and off, and the transmission start-up time is less than 2us; and when the open-circuit reflected power of the power amplifier output port is too large, the closed-loop control protection of the PA power amplifier circuit is realized; the power amplifier alarm circuit converts the four-way comparison The output control signals are combined into one channel as the power amplifier alarm output, and also as the protection control input signal of the transmission control circuit; the PTT conversion circuit reverses the TX control level for switching the transceiver channel and the electronic switch; the over-temperature detection circuit monitors the actual temperature of the RF power amplifier device, and the output conversion analog voltage signal is sent to the micro-chip control circuit, and the PA power amplifier circuit output is cut off when the temperature is over; the over-current detection circuit monitors the working current of the RF power amplifier device, and the output conversion analog voltage signal is sent to the micro-chip control circuit, and the PA power amplifier circuit output is cut off when the current is too large; the power supply voltage stabilization circuit steps down and stabilizes the 24V DC voltage twice to provide the required DC voltage for the RF power amplifier device; the power supply conversion and power amplifier control circuit realizes positive and negative standing waves, over-temperature, over-current detection, transmission power control, alarm output and linear voltage regulation functions.

[0008] The high-power radio frequency electronic switch of the RF power electronic switch circuit realizes the switching of the transceiver channel. When the transceiver control signal TX is at a high level, the transmitting channel power amplifier works, and when it is at a low level, the receiving channel works; the LC low-pass filter circuit is composed of inductors L4~L7 and capacitors C46~C48 to form a seven-level Butterworth filter, which realizes the minimum fluctuation and loss in the passband and achieves harmonic and clutter suppression; the circulator is used for unidirectional transmission of radio frequency power, realizes isolation between the output end of the power amplifier and the load, and realizes reflected power detection during transmission; the RF power electronic switch circuit realizes the switching of the radio frequency front-stage transceiver channel and the detection of positive and negative standing wave input power.

[0009] When the RF power electronic switch circuit is subjected to a larger output power, a discrete high-power RF electronic switch constructed by multiple PIN high-power diodes MA4P504-1072 and inductors can be used to replace the U1 high-power RF electronic switch MASW-000936, with an output power of up to 45dBm or more; a circuit constructed by discrete devices including transistor SO642 and MMBTA92LT1 is used to replace the MADR-009150 drive controller U8, achieving an average output power of up to 45dBm or more without burning the high-power RF electronic switch and avoiding the risk of discontinuation and embargo of foreign integrated high-power electronic switches and supporting integrated drive control chips, and effectively reducing costs.

[0010] The PA power amplifier circuit of the power driving module circuit is mainly composed of a power driving amplifier tube and a final power push amplifier tube to realize linear amplification of radio frequency power; the low-power electronic switch realizes further high isolation of the receiving channel from the transmitting signal to prevent the burning of the LNA low-noise amplifier; the baseband transceiver electronic switch realizes the independent switching processing function of one antenna port JD_ANT of the self-organizing network transmission module and two independent channels of power amplifier transceiver.

[0011] The device shell is composed of an outer shell and a heat sink, and the power driving amplifier tube and the final power driving amplifier tube of the PA power amplifier circuit of the power driving module circuit are directly installed on the heat sink; four radio frequency sockets, JD_ANT_RX, RF_ANT_RX, JD_ANT, and RF_ANT, are installed on the outer shell; +24V, TX, GND, and Alarm signals are respectively connected through four through-hole capacitors of the outer shell to realize 24V DC voltage input, TX control signal input, grounding, and power amplifier alarm output; the JD_ANT_RX radio frequency socket and the RF_ANT_RX radio frequency socket are connected to the corresponding pins of the LNA low noise amplifier box; the JD_ANT port on the outer shell is connected to the antenna port JD_ANT of the self-organizing network transmission module, and the RF_ANT port of the device shell is connected to the antenna port of the self-organizing network device or the RF_ANT port of the cavity filter. The cavity filter is connected when the background noise and spectrum interference are serious, and is not connected otherwise.

[0012] The transmitting power amplifier device has an operating frequency band of 640-670 MHz, and the transmitting and receiving channels are switched by a high-power radio frequency electronic switch U1; it is suitable for QPSK, BPSK, 16QAM, and 64QAM carrier modulation modes, and the transmitting channel power amplifier works when the transmitting and receiving control signal TX is at a high level, and the receiving channel works when the transmitting and receiving control signal TX is at a low level; the drain of the power driving amplifier tube and the final power driving amplifier tube are often energized, and the transmission start-up time is less than 2us by controlling the low voltage on and off of its gate bias; the average output power is 41.8 dBm, the amplification gain is ≥24 dB, the isolation of the RF power electronic switch at the output end of the power amplifier is ≥70 dB, the in-band fluctuation is ≤1 dB, the harmonic spurious suppression is above -80 dBc, the third-order intermodulation is ≤-35 dBc when the two paths are spaced 600 kHz and the carrier power output of each path is 38.8 dBm, and it can work continuously for more than 24 hours.

[0013] The beneficial effects of the present invention compared with the prior art are:

[0014] The RF power amplification device for transmitting video in a self-organizing network is equipped with a RF power amplifier device mode through a self-organizing network transmission module. The working parameters of the self-organizing network transmission module are configured through an RJ45 network port terminal, so that the RF power amplifier of the self-organizing network transmission equipment can work linearly within the frequency band of 640MHz to 670MHz. Compared with the existing self-organizing network equipment, the communication transmission distance is increased by more than 10 times; the transmission and reception switching time is fast, the transmission start time is less than 2us, the average output power is 41.8dBm, the maximum gain is 24dB, the RF power electronic switch isolation at the output end of the power amplifier is ≥70dB, the in-band fluctuation is ≤1dB, the harmonic spurious suppression is above -80dBc, the two working frequency intervals differ by 600kHz and the third-order intermodulation is ≤-35dBc when the carrier power output of each channel is 38.8dBm, and it has the ability to work continuously for more than 24 hours. By using a discrete device circuit board built with PIN high-power diodes and triodes to replace the RF power electronic switch circuit in situ, an average power output of up to 45dBm is achieved without burning the high-power RF electronic switch; high-power, long-distance wireless video transmission is achieved, and the two-way video can reach up to 12Km, the RF signal attenuation of the receiving channel is small, the harmonic clutter suppression of the transmitting channel is high, the switching time of sending and receiving is fast, the video signal transmission is stable, the communication rate is high, the interface is simple, and it has over-current, over-temperature, open-short circuit protection and alarm functions, low production cost, easy operation, and outstanding substantive features suitable for information communication between small-scale vehicle formations. It solves the problems of low power output, short wireless video transmission distance, low practicality, and unsuitability for information communication between small-scale vehicle formations in the existing self-organizing network equipment for information communication between small-scale vehicle formations in a certain area, and fully meets the requirements of military and civilian information communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a block diagram of the working principle of the present invention;

[0016] Figure 2 It is a block diagram of the working principle of the radio frequency power amplifier device of the present invention;

[0017] Figure 3 It is a schematic diagram of the planar structure of the radio frequency power amplifier device of the present invention;

[0018] Figure 4 It is a side structural schematic diagram of the radio frequency power amplifier device of the present invention;

[0019] Figure 5 It is a schematic diagram of the top view of the structure of the radio frequency power amplifier device of the present invention;

[0020] Figure 6 It is the circuit diagram of power conversion and power amplifier control;

[0021] Figure 6-1 The circuit diagram of logarithmic forward detection and logarithmic reverse detection of the power conversion and power amplifier control circuit;

[0022] Figure 6-2 The circuit diagram of the power conversion and power amplifier control circuit, the PTT conversion circuit and the power amplifier alarm circuit;

[0023] Figure 6-3 The circuit diagram of the overcurrent detection circuit and the power supply voltage stabilization circuit of the power conversion and power amplifier control circuit;

[0024] Figure 7 It is the circuit diagram of RF power electronic switch;

[0025] Figure 7-1 The circuit diagram of a high-power radio frequency electronic switch, a drive controller and a low-power electronic switch of an RF power electronic switch circuit;

[0026] Figure 7-2 The circuit diagram of the LC low-pass filter and circulator for the RF power electronic switching circuit;

[0027] Figure 7-3 Build circuits for discrete devices that replace high-power RF electronic switches and drive controllers in RF power electronic switch circuits, as well as circuit diagrams for low-power electronic switches;

[0028] Figure 8 This is the circuit diagram of the power drive module;

[0029] Figure 8-1 The circuit diagram of the power driving amplifier tube, baseband transceiver electronic switch and low-power electronic switch of the PA power amplifier circuit of the power driving module circuit;

[0030] Figure 8-2It is a circuit diagram of the final-stage power driving amplifier tube of the PA power amplifier circuit of the power driving module circuit;

[0031] Fig. 9 It is a schematic diagram of the three-dimensional structure of the radio frequency power amplifier device of the present invention;

[0032] Fig.10 It is a transmission debugging connection diagram of the radio frequency power amplifier device of the present invention;

[0033] Fig.11 A receiving debugging connection diagram of the radio frequency power amplifier device of the present invention;

[0034] Fig.12 It is a schematic diagram of the assembly of the circuit board of the power conversion and power amplifier control circuit of the radio frequency power amplifier device of the present invention, the circuit board of the RF power electronic switch circuit, the circuit board of the power drive module circuit and the circulator;

[0035] Fig.13 The present invention is a schematic diagram of a circuit board of a replacement radio frequency electronic switch, a drive controller circuit and a low-power electronic switch for the RF power electronic switch circuit of the radio frequency power amplifier device.

[0036] In the figure: A, RF power amplifier device, A1, power conversion and power amplifier control circuit, A2, RF power electronic switch circuit, A3, power drive module circuit, A4, device housing, A40, housing, A41, heat sink;

[0037] U5, micro single chip microcomputer, U3 / U4, transmission control circuit, U6, logarithmic forward detection circuit, U7, logarithmic reverse detection circuit, U18, over-current detection circuit, U13 / U14, over-temperature detection circuit, U10, PTT conversion circuit, U11, power amplifier alarm circuit, U15 / U16, power supply voltage stabilization circuit;

[0038] U1, high power RF electronic switch, U8, drive controller, U9, low power electronic switch, Z1, circulator, Z2, power attenuator;

[0039] V1 / V2, PA power amplifier circuit, V1, power drive amplifier tube, V2, final stage power push amplifier tube, U2, baseband transceiver electronic switch, U12, low power electronic switch circuit. DETAILED DESCRIPTION

[0040] Briefly describe the design concept of the present invention: Although wireless communication equipment is constantly upgraded and rapidly developed, due to the equipment construction cost, equipment use requirements and technical limitations, most general-purpose vehicles still do not have reliable and secure information communication transmission means. When a general-purpose vehicle fleet is on the way to perform a mission, generally only the command vehicle has information communication capabilities, and there is no suitable communication means between member vehicles or between member vehicles and the command vehicle.

[0041] In order to meet the actual communication needs of small-scale general-purpose vehicle formations, it is necessary to carry out research, design and manufacture of video, audio and voice transmission. The self-organizing network transmission module currently adopts QPSK, BPSK, 16QAM and 64QAM adaptive carrier modulation technology, which has strong anti-multipath fading ability. It can temporarily, dynamically and quickly build a wireless IP network without relying on any basic communication facilities. It has self-organization, self-recovery and high anti-destruction capabilities, supports multi-hop transmission of data, voice, video and many other media services, and provides a reliable and stable platform for information transmission between small-scale general-purpose vehicle formations in the region; through this platform, install APP application terminal software on the mobile phone or directly access the IP address of the network camera through the PC to realize two-way communication of video, voice and short messages. It is suitable for point-to-point, point-to-multipoint, and multipoint-to-multipoint wireless transmission application scenarios, and has chain, star and hybrid topology network architecture.

[0042] However, the above-mentioned fully functional ad hoc network transmission module has the disadvantages of low power output, short wireless video transmission distance, low practicality, and is particularly unsuitable for video and voice information transmission between general vehicle formations. In order to make the wireless video communication transmission distance longer and the transmission quality higher, the RF signal of the ad hoc network transmission module must be amplified without distortion. Therefore, a video transmission linear RF power amplifier is developed, and an ad hoc network device is constructed with an ad hoc network transmission module plus an RF power amplifier device A mode, so as to achieve the purpose of strong adaptability and operability, fast implementation of technical solutions, low cost risk, and outstanding use effect (see Figures 1 to 13 ),in Figure 1 The schematic block diagram of the working principle of the RF power amplifier device for transmitting video in a self-organizing network of the present invention is shown in FIG. The RF power amplifier device for transmitting video in a self-organizing network is composed of a RF power amplifier device A, an LNA low noise amplifier box, a cavity filter, a self-organizing network transmission module, a self-organizing network device panel and a power supply unit to form a complete self-organizing network device; wherein the RF power amplifier device A is composed of a power conversion and power amplifier control circuit A1, an RF power electronic switch circuit A2, and a power drive module circuit A3, and operates in the frequency band of 640 to 670 MHz (see FIG. Figure 2 ), Figure 2 It is a block diagram of the working principle of the radio frequency power amplifier device A of the present invention.

[0043] In the flat test environment of Jianghan Plain, two suction cup antennas are placed on the top of a moving vehicle, and under the test condition of a transmission power of 41.5dBm: the two-way video transmission distance of the RF power amplifier device for self-organizing network video transmission in the 640-670MHz frequency band of the present invention can reach 12Km, and the communication transmission distance of the RF power amplifier device for self-organizing network video transmission of the present invention is more than 10 times higher than that of the self-organizing network transmission module; and the RF signal attenuation of the receiving channel is small, the harmonic clutter suppression rate of the transmitting channel is high, the sending and receiving switching time is fast, the video signal transmission is stable, and the practical effect is outstanding.

[0044] The following is a further detailed description of the implementation of the RF power amplification device for transmitting video in the self-organizing network in conjunction with the accompanying drawings (see Figures 1 to 13 ):

[0045] A radio frequency power amplification device for transmitting video in an ad hoc network, which is composed of an ad hoc network transmission module, a radio frequency power amplifier device A, an LNA low noise amplifier box and a cavity filter; the ad hoc network transmission module includes a main video processing chip, an auxiliary video processing chip, frequency synthesis and up and down frequency conversion processing, a radio frequency switch, etc.; the wired data signal received by the RJ45 network port terminal and the wireless signal received by the 2.4GHz antenna are sent to the main video processing chip for combined processing, the combined data is sent to the auxiliary video chip for data processing, and the data signal is generated into an analog radio frequency signal output through the digital-to-analog conversion circuit integrated by the auxiliary video, and the output radio frequency signal is sent to the main video processing chip through BPF bandpass filtering, frequency synthesis down frequency conversion processing, power amplifier filtering and radio frequency switch. To the RF power amplifier device, after passing through the cavity filter, it is transmitted by the 650MHz antenna; the RF signal received by the 650MHz antenna is received by the RF power amplifier device, amplified by the LNA low-noise amplifier box, and then enters the RF power amplifier device. The received amplified signal from the power amplifier is then sent to the RF switch in the self-organizing network transmission module, and is transmitted to the frequency synthesizer up-converted into an RF signal through the receiving channel low noise broadcast, and then sent to the auxiliary video processing chip after BPF bandpass filtering. The data signal after the received RF signal is digitized is finally sent to the main video processing chip for exchange and forwarding processing, and the wired data is sent to the RJ45 network port terminal, and wirelessly transmitted through the 2.4GHz antenna to complete the self-organizing network video transmission communication.

[0046] The transceiver control signal output end of the main video processing chip is connected to the transceiver control signal TX input pin of the RF power amplifier device A through a wire, and the RF power amplifier device A is composed of a power conversion and power amplifier control circuit A1, an RF power electronic switch circuit A2, a power drive module circuit A3 and a device housing A4; the RF power amplifier device A is connected to the LNA low noise amplifier box through the device housing A4; the device housing A4 is composed of a shell A40 and a heat sink A41, and the circuit board of the power conversion and power amplifier control circuit A1, the circuit board of the RF power electronic switch circuit A2 and the circuit board of the power drive module circuit A3 are respectively installed on the heat sink A41, and are sealed and shielded by the shell A40;

[0047] The power conversion and power amplifier control circuit A1 is composed of a micro single-chip microcomputer U5, a transmission control circuit U3 / U4, a logarithmic forward detection circuit U6, a logarithmic reverse detection circuit U7, an overcurrent detection circuit U18, an overtemperature detection circuit U13 / U14, a PTT conversion circuit U10, a power amplifier alarm circuit U11 and a power supply voltage stabilization circuit U15 / U16; the RF power electronic switch circuit A2 is composed of a high-power radio frequency electronic switch U1, a low-power electronic switch U9, an LC low-pass filter circuit and a circulator Z1; the power drive module circuit A3 is composed of a PA power amplifier circuit V1 / V2, a baseband electronic transceiver switch U2 and a low-power electronic switch U12 (see Figure 1 to Figure 8-2 , Fig. 9 ).

[0048] Among them, PIC16F882-I micro single-chip computer U5 is mainly used for four-way AD input detection, four-way comparison judgment and output control. AD8362 logarithmic forward detector U6 is used for standing wave forward detection, AD8362 logarithmic reverse detector U7 is used for standing wave reverse detection; U18 is used for overcurrent detection, U13 and U14 are used for overtemperature detection, U11 four-way input OR gate 74HC32D combines four-way comparison judgment output control signals into one as the power amplifier alarm ALARM output, PTT conversion circuit U10 inverter 74HC04D reverses the TX control level RXPTT, and is used together with TXPTT for transceiver channel and electronic switch switching control, U15 and U16 are used for power supply voltage reduction and voltage regulation.

[0049] The logarithmic forward detection circuit U6 and the logarithmic reverse detection circuit U7 are used for forward and reverse detection of the transmission power standing wave. The sampled detected power signal is attenuated by the π-type matching network, converted into a DC voltage by the logarithmic detector, and sent to the micro single-chip computer U5 for analog-to-digital AD conversion. Then the single-chip computer compares and judges the average value of the five groups of ADC values ​​stored and the threshold value. When the value is greater than the judgment threshold, it outputs a low level, and when the value is lower than the judgment value, it outputs a high level. The output control signals RC0 and RC1 are combined by U11 or gate 74HC32D and output from pin 8. The 8-pin alarm control ALARM signal directly controls the on-off of IRF7316. Then, another IRF7316 field effect tube controlled by RXPTT jointly completes the on-off control of the DC bias power supply +5V of the power amplifier, thereby forming a closed-loop automatic control to achieve closed-loop detection control and protection of the forward standing wave.

[0050] U7 model is AD8362ARU for standing wave reverse detection. When the antenna is open, the reflected power increases rapidly. After passing through the circulator, the power is attenuated first and then sent to U7. After the DC voltage is converted by the logarithmic detector, it is sent to the PIC16F882-I microcontroller U5 for analog-to-digital processing and data comparison. The subsequent processing is exactly the same as the forward power detection processing flow. When the output port of the power amplifier is open, the power amplifier is protected by closed-loop control due to excessive reflected power.

[0051] The transmission control circuit U3 / U4 is composed of two cascaded field effect tubes IRF7316. The 8-pin alarm control output signal ALARM and the RX_PTT signal of the power amplifier alarm circuit U11 jointly cascade control the gates of the series-connected field effect tubes U3 and U4, so as to achieve the purpose of controlling whether the source and drain of U4 and U3 have a +5V analog voltage TX_PTT_C on and off. After TX_PTT_C is adjusted to a 1.91V DC voltage by the potentiometers RP1 and RP2 of the PA power amplifier circuit V1 / V2, a low DC voltage bias is provided to the V1 and V2 power amplifier tubes. The low DC bias voltage is controlled by the TX transceiver switching of the self-organizing network transmission module and various protection cascade signals, and the drain of V1 and V2 is often added with a high voltage, so that the transmitting power amplifier rise start time is less than 2us.

[0052] The power amplifier alarm circuit U11 combines the four comparison and judgment output control signals into one as the power amplifier alarm output, and also serves as the protection control input signal of the transmission control circuit; the PTT conversion circuit U10 reverses the control level of the transceiver control signal TX, which is used for switching the transceiver channel and the electronic switch; the over-temperature detection circuit U13 / U14 monitors the current actual ambient temperature of the RF power amplifier device A through sensing, converts the temperature into an analog voltage and sends it to the micro-chip microcomputer U5 control circuit for analog-to-digital conversion and comparison processing. When the temperature is too high, the RC5 output control signal is combined into an ALARM signal through four OR gates to cut off the gate bias voltage of the PA power amplifier circuit V1 / V2, so that the PA power amplifier circuit V1 / V2 has no power output. When the temperature is normal, the bias voltage works normally; the over-current detection circuit U13 / U14 monitors the current actual ambient temperature of the RF power amplifier device A through sensing, converts the temperature into an analog voltage and sends it to the micro-chip microcomputer U5 control circuit for analog-to-digital conversion and comparison processing. When the temperature is too high, the RC5 output control signal is combined into an ALARM signal through four OR gates to cut off the gate bias voltage of the PA power amplifier circuit V1 / V2, so that the PA power amplifier circuit V1 / V2 has no power output. When the temperature is normal, the bias voltage works normally. The wave circuit U18 monitors and outputs different analog voltages and sends them to the control circuit of the micro-MCU U5. When the current is too large, the gate bias voltage of the PA power amplifier circuit V1 / V2 is cut off, so that the PA power amplifier circuit V1 / V2 has no power output, thereby achieving the purpose of protecting the power amplifier. When the current is less than the detection threshold, the power amplifier transceiver is only controlled by the transceiver control signal TX; the power supply voltage regulator circuit U15 / U16 performs two voltage reduction and voltage regulation on the 24V DC voltage to improve the power conversion efficiency and provide the required DC voltage for the RF power amplifier device A; the micro-MCU U5 software mainly consists of ADC interrupt service program, four pairs of AD startup programs, four pairs of AD conversion programs, four pairs of data comparison judgment programs, and four pairs of output high and low level external flip control to protect the power amplifier from working in abnormal state without damage. The power conversion and power amplifier control circuit A1 realizes positive and negative standing wave detection and protection control, over-temperature detection and protection control, over-current detection and protection control, transmission power transceiver control, alarm output, and linear voltage regulation functions.

[0053] The RF power electronic switching circuit A2 (see Figure 7) is mainly composed of a high-power RF electronic switch U1, a drive controller U8, a low-power electronic switch U9, an LC low-pass filter circuit and a circulator Z1; when the transceiver control signal TX is at a high level, the transmitting channel power amplifier works, and when the transceiver control signal TX is at a low level, the transmitting channel has no amplification gain and the receiving channel works; the LC low-pass filter circuit is composed of inductors L4~L7 and capacitors C46~C48 to form a seven-level Butterworth filter, which can minimize the fluctuation and loss in the passband and suppress harmonics and clutter; the Z1 circulator TH0702M1 is mainly used to transmit RF power in one direction, realize isolation between the output end of the power amplifier and the load, and realize reflected RF power detection during power transmission. When the V2 final power drives the amplifier to output a high-power RF signal, it is transmitted to the next port in the direction sequence determined by the static bias magnetic field of the circulator Z1, and the transmission power signal input from its port 1 is sent to the LC low-pass filter from port 2; similarly, the reflected power signal input from its port 2 is sent out from port 3, and is sent to the logarithmic reverse detector U7 for reverse power detection after secondary attenuation by the SHX-50-20dB power attenuator Z2 and the Π-type network.

[0054] U1 high-power RF electronic switch MASW-000936, U8 drive controller MADR-009150, and U9 low-power electronic switch HMC484MS8G together form the RF power electronic switch circuit A2, which realizes the RF front-stage transceiver channel switching and positive and negative standing wave input power detection, and also realizes high isolation of transceiver signals.

[0055] The PA power amplifier circuit V1 / V2 of the power driving module circuit A3 is mainly composed of a power driving amplifier tube V1 and a final power push amplifier tube V2 to realize linear amplification of RF power; the HMC8038LP4CE low-power electronic switch U12 realizes further high isolation of the receiving channel to the transmitting signal to prevent the burning of the LNA low-noise amplifier box; the HMC646LP2E baseband transceiver electronic switch U2 realizes the independent switching processing function of one antenna port JD_ANT of the self-organizing network transmission module and two independent channels of power amplifier transceiver.

[0056] The device housing A4 is composed of a shell A40 and a heat sink A41. The power drive amplifier tube V1 and the final power push amplifier tube V2 of the PA power amplifier circuit V1 / V2 of the power drive module circuit A3 are directly installed on the heat sink A41; the shell A40 is equipped with JD_ANT_RX radio frequency socket, RF_ANT_RX radio frequency socket, JD_ANT radio frequency socket, and RF_ANT radio frequency socket. The +24V, TX, GND, and Alarm signals are respectively connected to the shell A40 through four through-hole capacitors of the shell 40. The JD_ANT_RX and RF_ANT_RX radio frequency sockets are connected to the corresponding pins of the LNA low noise amplifier box; the JD_ANT port on the housing A40 is connected to the antenna port JD_ANT of the ad hoc network transmission module, and the RF_ANT port of the device housing (A4) is connected to the antenna port of the ad hoc network device or the RF_ANT port of the cavity filter. The cavity filter is connected when the background noise and spectrum interference are serious, otherwise it is not connected.

[0057] The transmitting power amplifier device A has an operating frequency band of 640-670 MHz, and the transmitting and receiving channels are switched by a high-power radio frequency electronic switch U1; it is suitable for QPSK, BPSK, 16QAM, and 64QAM carrier modulation modes, and the transmitting channel power amplifier works when the transmitting and receiving control signal TX is at a high level; when the transmitting and receiving control signal TX is at a low level, the transmitting channel has no amplification gain, and the receiving channel works; the power driving amplifier tube V1 and the final power driving amplifier tube V2 of the PA power amplifier circuit V1 / V2 are always powered on, and the transmission start-up time is less than 2us by controlling the low voltage on and off of the gate bias of the power amplifier tubes V1 and V2; the average output power is 41.5 dBm, the amplification gain is ≥24 dB, the isolation of the RF power electronic switch at the output end of the power amplifier is ≥70 dB, the in-band fluctuation is ≤1 dB, the harmonic spurious suppression is above -80 dBc, the third-order intermodulation is ≤-35 dBc when the two channels are spaced 600 kHz and the carrier power output of each channel is 38.8 dBm, and it can work continuously for more than 24 hours.

[0058] The power conversion and power amplifier control circuit A1 is composed of a PIC16F882-I micro-chip computer U5, an IRF7316 transmission control circuit U3 / U4, an AD8362 logarithmic forward detection circuit U6, an AD8362 logarithmic reverse detection circuit U7, an LTC6101 overcurrent detection circuit U18, an LM50CIM3 overtemperature detection circuit U13 / U14, a 74HC04D PTT conversion circuit U10, a 74HC32D power amplifier alarm circuit U11, and a MIC29302BT power supply voltage regulator circuit U15 / U16; (See Figure 6 , Figure 6-1 , Figure 6-2 and 6-3).

[0059] Figure 6 Figure A1 is a power conversion and power amplifier control circuit.

[0060] Figure 6-1 for Figure 6 A1 power conversion and amplifier control circuit split diagram (to show more clearly Figure 6 details), Figure 6-1 Specifically, it is the circuit diagram of AD8362 logarithmic forward detector circuit U6 and AD8362 logarithmic reverse detector circuit U7.

[0061] Figure 6-2 for Figure 6 The disassembled diagram of the power conversion and power amplifier control circuit A1. Figure 6-2 Specifically, it is the circuit diagram of PIC16F882-I microcontroller U5, IRF7316 transmitter control circuit U3 / U4 (two field effect transistors), 74HC04E PTT conversion circuit U10, and 74HC32D power amplifier alarm circuit.

[0062] Figure 6-3 for Figure 6 The disassembled diagram of the power conversion and power amplifier control circuit A1, specifically the circuit diagram of the LTC6101 overcurrent detection circuit U18, and the MIC29302BT power supply voltage regulator circuit U15 / U16 circuit.

[0063] ( Figure 6-2 and Figure 6-3 Connection): Figure 6-2 The 5th pin (AN2) of the PIC16F882-I microcontroller U5 in the ( Figure 6-3 ) is connected to pin 1 (OUT) of LTC6101 overcurrent detection circuit U18.

[0064] The RF power electronic switch circuit A2 is composed of a MASW-000936 high-power RF electronic switch U1, a MADR-009150 drive controller U8, a HMC484MS8G low-power electronic switch U9, an LC low-pass filter circuit and a circulator Z1; the LC low-pass filter circuit is composed of a seven-stage Butterworth filter composed of inductors L4-L7 / capacitors C46-C48, and the circulator Z1 is used for unidirectional transmission of RF power; the RF power electronic switch circuit A2 realizes the switching of the transceiver channel and the high isolation of the transceiver signal, realizes the isolation between the output end of the power amplifier and the load, and the transmission power detection (see Figure 7 , Figure 7-1 , Figure 7-2 and Figure 7-3 ).

[0065] Figure 7Figure A2 is a diagram of an RF power electronic switching circuit.

[0066] Figure 7-1 for Figure 7 Exploded diagram of RF power electronic switch circuit A2 (for clearer presentation) Figure 7 details), Figure 7-1 Specifically, it is the circuit diagram of MASW-000936 high-power RF electronic switch U1, MADR-009150 drive controller U8, and HMC484MS8G low-power electronic switch U9.

[0067] Figure 7-2 for Figure 7 A breakdown of the RF power electronic switch circuit A2, specifically the circuit diagram of the TH0702M1 circulator Z1 and the DLC70B6R8BW501XT seven-stage Butterworth LC low-pass filter.

[0068] ( Figure 7-1 and Figure 7-2 Connections): Figure 7-1 The 14th foot (TX) of the MASW-000936 high-power RF electronic switch U1 is connected to ( Figure 7-2 The capacitor C49 is connected to ( Figure 7-2 ) LC low pass filter connection.

[0069] Figure 7-3 for Figure 7-1 The circuit diagram of replacing the discrete devices of the high-power RF electronic switch U1 and the drive controller U8 in the circuit diagram (see Figure 7-3 ) When the RF power electronic switch circuit is subjected to a larger output power, the discrete device high-power RF electronic switch circuit constructed by multiple PIN high-power diodes MA4P504-1072 and inductors and the discrete device circuit constructed by transistor SO642 and MMBTA92LT1 can replace the U1 high-power RF electronic switch MASW-000936 and MADR-009150 driver controller U8 in situ, with an output power of more than 45dBm, and an average output power of more than 45dBm will not burn the high-power RF electronic switch, and successfully avoid the risk of discontinuation and embargo of foreign integrated high-power electronic switches and supporting integrated drive control chips, and effectively reduce costs.

[0070] The power drive module circuit A3 is mainly composed of a PA power amplifier circuit, a baseband transceiver electronic switch, and a low-power electronic switch; the PA power amplifier circuit is mainly composed of two-stage power amplifiers V1 and V2 to achieve power linear amplification; V1 is a BLF6G21-10G power drive amplifier tube, and V2 is a BLF6G10LS-135R final-stage power push amplifier tube; the power amplifier baseband input port of the HMC646LP2E baseband transceiver electronic switch U2 requires two input powers with a frequency difference of 600KHz, and each power is 38.8dBm. The two input powers are synthesized into one through a three-way device and sent to the JD-ANT port of the baseband transceiver electronic switch U2. During testing, the JD-ANT port is connected to the signal source E4432B to test an indicator of power amplifier linearity and third-order intermodulation; The 9th pin (RF1) of the HMV8038LP4CE low-power electronic switch U12 is connected to the JD_ANT_RX port through the capacitor C6; the power drive module circuit A3 realizes the RF power amplification and the power amplifier pre-stage transceiver channel switching (see Figure 8 , Figure 8-1 and Figure 8-2 ).

[0071] Figure 8 This is the power drive module circuit A3 diagram.

[0072] Figure 8-1 for Figure 8 A split diagram of the power drive module circuit A3 (in order to show more clearly Figure 8 details), Figure 8-1 Specifically, it is a circuit diagram of the BLF6G21-10G power driver amplifier V1 and the HMC8038LP4CE low-power electronic switch U12 of the PA power amplifier circuit.

[0073] Figure 8-2 for Figure 8 The split diagram of the power drive module circuit A3, Figure 8-2 Specifically, it is a circuit diagram of the BLF6G10LS-135R final-stage power driver amplifier V2 of the PA power amplifier circuit and its 24V_POWER power supply.

[0074] ( Figure 8-1 and Figure 8-2 Connections): Figure 8-1 The resistor R15 at the output of the BLF6G21-10G power driver amplifier V1 is connected to the resistor R15 at the output of the BLF6G21-10G power driver amplifier V1. Figure 8-2 The capacitor C14 is connected to the gate of the final power driving amplifier V2 of BLF6G10LS-135R; ( Figure 8-2 The adjustable resistor RP2 and ( Figure 8-1 The adjustable resistor RP1 in the figure is connected to the TX_PTT_C port.

[0075] The device housing A4 is composed of a shell A40 and a heat sink A41. The circuit board of the power conversion and power amplifier control circuit A1, the circuit board of the RF power electronic switch circuit A2 and the circuit board of the power drive module circuit A3 are respectively and individually mounted on the heat sink A41. The power drive amplifier tube V1 and the final power push amplifier tube V2 of the PA power amplifier circuit in the power drive module circuit A3 are directly mounted on the heat sink A41 (see Figure 3 , Figure 4 , Figure 5 , Figure 8-1 and Figure 8-2 ).

[0076] The shell A40 is equipped with JD_ANT_RX RF socket, RF_ANT_RX RF socket, JD_ANT RF socket, RF_ANT RF socket and +24V power socket; the JD_ANT_RX RF socket and RF_ANT_RX RF socket are connected to the corresponding pins of the LNA low noise amplifier box; the JD_ANT port on the shell A40 is connected to the antenna port JD_ANT of the ad hoc network transmission module, and the RF_ANT port of the device shell A4 is connected to the antenna port of the ad hoc network device or the RF_ANT port of the cavity filter. The cavity filter is connected when the background noise and spectrum interference are serious, otherwise it is not connected. (See Figure 1 to Figure 5 and Fig. 9 ).

[0077] The transmitting power amplifier device has an operating frequency band of 640-670 MHz, and the transmitting and receiving channels are switched by the MASW-000936RF high-power radio frequency electronic switch U1 of the RF power electronic switch circuit A2; it is suitable for QPSK, BPSK, 16QAM, and 64QAM carrier modulation modes, and the transmitting channel power amplifier works when the transmitting and receiving control signal TX is at a high level, and the receiving channel works when the transmitting and receiving control signal TX is at a low level; the power driving amplifier tube V1 and the final power driving amplifier tube V2 are always powered on, and their power supply is controlled by controlling the input stage TX_PTT_C, so that the transmitting start-up time is less than 2us; the average output power is 41.8dBm, the maximum gain is 24dB, the isolation of the RF power electronic switch at the output end of the power amplifier is ≥70dB, the in-band fluctuation is ≤1dB, the harmonic spurious suppression is above -80dBc, the third-order intermodulation is ≤-35dBc when the two channels are spaced 600kHz and the carrier power output of each channel is 38.8dBm, and it can work stably and continuously for more than 24 hours.

[0078] During specific implementation, the outer shell A40 of the device shell A4 covers the circuit board of the power conversion and power amplifier control circuit A1, the circuit board of the RF power electronic switch circuit A2 and the circuit board of the power drive module circuit A3 to provide sealing and shielding to prevent electromagnetic leakage; the power drive amplifier V1 and the final power push amplifier V2 are installed on the heat sink A41, and before installation, a proper amount of thermal conductive silicone grease is applied to the bottom of V1 and V2 to make them in close contact with the heat sink A41, which is conducive to natural heat dissipation; the heat sink A41 is cut with trapezoidal teeth with equal spacing to increase the heat dissipation area, and the plate material of the outer shell A40 is aluminum alloy.

[0079] The JD_ANT_RX and RF_ANT_RX of the shell A40 can be connected to the JD_ANT_RX and RF_ANT_RX pins on the external LNA low noise amplifier box, and can also be directly short-circuited through the RF line for use; the JD_ANT port of the shell A40 is connected to the antenna port JD_ANT of the ad hoc network transmission module, and the RF_ANT port of the shell A40 is connected to the antenna port of the ad hoc network device or the RF_ANT port of the cavity filter. The cavity filter is a non-essential unit, which is added when the background noise and spectrum interference are serious and removed in other cases; the +24V of the shell A40 is used for DC 24V power input, and the transceiver control signal TX of the shell A40 is used for PTT transceiver control signal input, and the PTT transceiver control signal is sent by the PTT of the ad hoc network transmission module; the alarm ALarm is used to indicate that the power amplifier state is abnormal; the RF power amplifier device A is made into a module component, and its application in the ad hoc network device (see Fig.12 ), Fig.12 It is a schematic diagram of the assembly of the circuit board of the power conversion and power amplifier control circuit A1 of the RF power amplifier device A, the circuit board of the RF power electronic switch circuit A2, the circuit board of the power drive module circuit A3 and the circulator; the external interface of the RF power amplifier device A is shown in Table 1.

[0080] Table 1 External interfaces of RF power amplifier device A

[0081]

[0082] (See Figure 6 ) The power conversion and power amplifier control circuit A1 is composed of a micro single-chip computer U5, a control circuit U3 / U4, a logarithmic forward detection circuit U6, a logarithmic reverse detection circuit U7, an overcurrent detection circuit U18, a PTT conversion circuit U10, a power amplifier alarm circuit U11, an overtemperature detection circuit U13 / U14, and a power supply voltage stabilization circuit U15 / U16.

[0083] Among them, the PIC16F882-I micro-chip microcomputer U5 is mainly used for four-way AD detection and comparison judgment output control.

[0084] The transmission control circuit U3 / U4 is mainly composed of two IRF7316 field effect tubes U3 and U4 in cascade connection, which are controlled together with the RX_PTT signal.

[0085] The LTC6101 overcurrent detection circuit U18 is used for overcurrent protection; the LM50CIM3 overtemperature detection circuit U13 / U14 is used for overtemperature detection; the 74HC32D power amplifier alarm circuit U11 combines four comparison and judgment output control ports into one as the power amplifier alarm output; the 74HC04D in the PTT conversion circuit U10 inverts the control level of the transceiver control signal TX for switching between transceiver channels and electronic switches, and the MIC29302BT power supply voltage regulator circuit U15 / U16 is used for power supply voltage reduction and voltage regulation.

[0086] The model of the logarithmic forward detection circuit U6 is AD8362ARU, which performs standing wave forward detection. The transmitting RF output power is attenuated by a π-type matching network, and the attenuated power signal is detected by a logarithmic detector to become a DC signal, which is sent to the PIC16F882-I micro-chip computer U5 for AD conversion processing. Then, the PIC16F882-I micro-chip computer U5 compares and judges the average values ​​of the five groups of ADC values ​​stored. When the value is greater than the judgment threshold, a low level is output, and when the value is less than the judgment value, a high level is output. The high and low levels of the output are directly controlled by the 74HC32D power amplifier alarm circuit U11 or gate processing to directly control the power conversion and power amplifier control circuit A1 (see Figure 6 , Figure 6-1 ) of the IRF7316 control circuit U3 / U4 field effect tube, and then the IRF7316 field effect tube U3 and U4 cascaded by RXPTT control together complete the power drive module circuit A3 (see Figure 8 , Figure 8-1 and Figure 8-2 ) by controlling the on-off of the DC bias power supply of the power driving amplifier V1 and the final power pushing amplifier V2, thereby forming a closed-loop automatic control to realize the positive closed-loop detection control of the standing wave.

[0087] When the antenna is open, the rapidly increasing reflected power is attenuated by the circulator Z1 and then sent to the AD8362ARU logarithmic reverse detection circuit U7 for standing wave reverse detection. After being converted into DC voltage by the logarithmic detector, it is sent to the PIC16F882-I microcontroller U5 control circuit. The subsequent processing is exactly the same as the above-mentioned forward power detection process. When the output port of the power amplifier is open, the power amplifier is protected by closed-loop control due to excessive reflected power.

[0088] The over-temperature detection circuit uses TC77-5.0MCTTR or LM50CIM3. The present invention uses the LM50CIM3 over-temperature detection circuit U13 / U14, monitors the actual temperature of the RF power amplifier device A through a sensor, and outputs different analog voltages. The analog voltage is then sent to the control circuit of the PIC16F882-I micro-chip computer U5. When the temperature is too high, the power output of the RF power amplifier device is cut off to achieve over-temperature protection.

[0089] The LTC6101 overcurrent detection circuit U18 implements overcurrent protection, and the overcurrent analog voltage is also sent to the PIC16F882-I microcontroller U5 for processing.

[0090] The two MIC29302BT chips U15 / U16 realize two-time voltage reduction and voltage regulation of the DC 24V voltage, and provide the required DC voltage to the RF power amplifier device A.

[0091] The software of the PIC16F882-I micro-chip U5 control circuit mainly consists of an ADC interrupt service program, four AD startup programs, four AD conversion programs and four data comparison and judgment programs, which are used to protect the power amplifier of the RF power amplifier device A from being damaged even when working in an abnormal state.

[0092] Through the coordinated work of the above-mentioned associated circuits of the power conversion and power amplifier control circuit A1, positive and negative standing wave detection, over-temperature detection, over-current detection, linear voltage regulation, alarm output and PTT transceiver control functions are realized.

[0093] The +24V, TX, GND, and Alarm of the housing A40 of the device housing A4 are connected to the circuit board of the power conversion and power amplifier control circuit A1 through the core capacitor, where +24V is the external DC power supply 24V input, TX is the PTT control input pin for sending and receiving, GND is the grounding pin, and Alarm is the alarm output pin (see Figure 3 ).

[0094] (See Figure 7 ) RF power electronic switch circuit A2, composed of RF power electronic switch, drive controller, LC low-pass filter, low-power electronic switch and circulator; LC low-pass filter is designed as a seven-stage Butterworth filter, composed of inductors L4~L7 and capacitors C46~C48, to minimize the fluctuation and loss in the passband and achieve harmonic and clutter suppression.

[0095] Circulator Z1 is used to transmit RF power in one direction, to achieve isolation between the power amplifier output and the load, and to detect the transmission power; (See Figure 6 , Figure 6-1 and Figure 6-2) The final power push amplifier V2 in the PTT conversion circuit outputs a high-power RF signal, which is transmitted to the next port in the direction determined by the static bias magnetic field. The transmission power signal input from port 1 of the circulator Z1 is sent out from port 2 to the LC low-pass filter; similarly, the transmission power signal input from port 2 of the circulator Z1 is sent out from port 3, attenuated twice by the SHX-50-20dB power attenuator Z2 and the resistor π-type network, and sent to the logarithmic reverse detector U7 for reverse power detection (see Figure 6-1 ).

[0096] The MASW-000936 high-power RF electronic switch U1, the MADR-009150 drive controller U8, and the HMC484MS8G low-power electronic switch U9 together constitute the RF power electronic switch circuit A2, which is mainly used for switching the transmitting and receiving channels, and at the same time, achieves high isolation of the transmitting and receiving signals.

[0097] Since the output power of the self-organizing network transmission module is adjustable through parameter configuration, when the JD_ANT input power of the self-organizing network transmission module exceeds 20dBm, the power amplifier output exceeds 43dBm, which usually burns out the MASW-000936 high-power RF electronic switch and the drive controller MADR-009150. In order to eliminate hidden dangers and improve reliability, a circuit constructed by discrete components of PIN high-power diode MA4P504-1072P (VD1~VD5) and inductor (L5~L14) can replace the high-power RF electronic switch integrated in MASW-000936 (U1). The circuit design (see Figure 7-3 , Fig.13 ), transistor SO642 (V1 ~ V3) and MMBTA92LT1 (V4) discrete devices build level flip and drive output circuit to replace MADR-009150 drive controller U8 in situ. In actual tests, the RF electronic switch circuit A2 output power 46dBm power amplifier device works normally, the insertion loss of the high-power RF electronic switch U1 is less than 0.3dB, the input and output isolation is greater than 40 dB, and the external interface and circuit board size are the same as the original RF power electronic switch circuit (see Figure 7-1 ) The circuit board is exactly the same and can be replaced in situ. The circuit board built with discrete components has a simple design, high output power, low general cost of components, high reliability, low insertion loss of transmission and reception, and high isolation.

[0098] (See Figure 7 ), the RF_ANT_RX radio frequency socket on the circuit board of the RF power electronic switch circuit A2 is connected to the LNA low noise amplifier box input port RF_ANT_RX, and the RF_ANT port on the circuit board is connected to the RF_ANT port of the cavity filter.

[0099] (See Figure 8), the power drive module circuit A3 is mainly composed of a PA power amplifier circuit, a baseband transceiver electronic switch and a low-power electronic switch; the PA power amplifier circuit is based on a two-stage power amplifier device BLF6G21-10G power driver amplifier V1 and a BLF6G10LS-135R final-stage power push amplifier V2 to achieve power linear amplification, the baseband transceiver electronic switch uses HMC646LP2E, and the low-power electronic switch uses HMC8038LP4CE, with an insertion loss of less than 0.5dB, to achieve pre-stage transceiver channel selection.

[0100] The BLF6G21-10G of the PA power amplifier circuit V1 / V2 of the power driving module circuit A3 is a 10W LDMOS field effect power driver amplifier tube V1, whose VDS voltage is 24V, gain is 18.5Db, efficiency is 31%, ACPR is -39dBc, and average effective output power is 2W; the BLF6G10LS-135R of the PA power amplifier circuit is a 135W LDMOS field effect final stage power driver amplifier tube V2, whose VDS voltage is 24V, gain is 21dB, efficiency is 28%, ACPR is -39dBc, and average effective output power is 26.5W, which serves as a final stage power driver amplifier; the PA power amplifier circuit V1 / V2 is used to realize rapid switching of RF power amplification and power amplifier pre-stage transceiver channel.

[0101] The JD_ANT port of the circuit board of the PA power amplifier circuit is connected to the JD_ANT port of the ad hoc network transmission module, and the JD_ANT_RX port of the circuit board is connected to the output JD_ANT_RX port of the LNA low noise amplifier box.

[0102] The material composition of the RF power amplifier device A is shown in Table 2.

[0103] Table 2 Material composition of RF power amplifier device A

[0104]

[0105] The debugging process of the RF power amplifier device A is as follows:

[0106] (See Fig.10 ) Fig.10 The figure is a schematic diagram of the transmission debugging connection of the radio frequency power amplifier device A of the present invention; the technical requirements for debugging the radio frequency power amplifier device A are as follows:

[0107] 1) The frequency point of RF power amplifier device A is selected as 650.000MHz, the receiving loss from RF_ANT to JD_ANT is 2.5dB±0.3dB; the amplification gain from JD_ANT to RF_ANT is greater than 24dB.

[0108] 2) Instruments and equipment for debugging RF power amplifier device A:

[0109] 1 set of 2955B comprehensive tester;

[0110] 1 PR35-3A-3C DC regulated power supply;

[0111] One QJ3020E voltage-stabilized power supply;

[0112] 1 ROHDE&SCHWARZ FSP spectrum analyzer;

[0113] 1 E4432B Agilent 250KHz~3.0GHz signal source;

[0114] 1 directional coupler.

[0115] 3) Equipment connection for transmitting and debugging of RF power amplifier device A (see Fig.10 ), the debugging steps are as follows:

[0116] Check whether there are any assembly errors, whether there are any components and solder joints on the front and back of the circuit board of the power conversion and power amplifier control circuit A1, the circuit board of the RF power electronic switch circuit A2, and the circuit board of the power drive module circuit A3 that are short-circuited to the ground or have cold solder joints, and whether the polarity of the electrolytic capacitor is installed incorrectly.

[0117] Connect the RF power amplifier device A+24V to be debugged with the 24V DC power supply, turn on the comprehensive tester and spectrum analyzer for a few minutes to preheat, and the comprehensive tester is working in the sending state; turn on the QJ3020E DC regulated power supply 24V, and connect the JD_ANT of the RF power amplifier device A to the E4432B signal source, which outputs a RF signal with a frequency of 650MHz and an amplitude of 0dBm; disconnect the power drive module circuit A3 (see Figure 8 ) and the capacitor C2 connected to the gate of the power driver amplifier V1, and the capacitor C8 is connected to the FSP spectrum analyzer, the PTT switch TX is set to the high level transmission state, and the FSP spectrum analyzer tests the power to be -6dBm±1.5dB; the isolation when the PTT switch transmit and receive control signal TX is set to the low level reception is ≥25dB; adjust the RP1 and RP2 potentiometer knobs in the PA power amplifier circuit (see Figure 8-1 , Figure 8-2 ), so that the gate voltage of the power driving amplifier V1 and the final power push amplifier V2 are both 1.96V±0.1V.

[0118] By adjusting the resistance values ​​of resistors R24, R23, R65, R17 and R18 of the final power amplifier V2, the attenuation from the output end of capacitor C15 to the output end of resistor R65 is 65dB (see Figure 8-2 ), connect the capacitor C15 output and the RF power electronic switch circuit A2 (see Figure 7) is connected to the input end of the circulator Z1 in the RF power amplifier device A, and the RF_ANT of the RF power amplifier device A is connected to the RF port of the 2955B comprehensive tester. When TX is set to a high-level transmitting state, the output power of the 2955B comprehensive tester is 42dBm±0.5dB, of which the insertion loss of the circulator Z1 is 0.35dB, the insertion loss of the 7th-order LC low-pass filter is 1.35dB, and the insertion loss of the U1 high-power RF electronic switch of the RF power electronic switch is 0.3dB. The harmonic spurious suppression is output through the directional coupler and directly read out by the FSP spectrum analyzer.

[0119] Install the circuit board of the power drive module circuit A3 on the heat sink A41 of the device housing A4. Before installation, apply a proper amount of thermal conductive silicone grease to the bottom of the power drive amplifier V1 field effect tube and the final power push amplifier V2 field effect tube to make them fully contact with the heat sink A41, which is conducive to natural heat dissipation; the JD_ANT of the RF power amplifier device A inputs a radio frequency signal with a frequency of 650MHz and an amplitude of 19dBm from the E4432B signal source, and the output end of the capacitor C15 is connected to the RF port of the 2955B comprehensive tester. When the PTT switch TX is placed in the high-level transmission state, the output power of the 2955B comprehensive tester is 44dBm±0.5dB, which effectively ensures that the gain of the power drive module circuit A3 is greater than 25dB. When a higher transmission power signal needs to be output, the discrete components of the RF power electronic switch circuit A2 are used to build a circuit to replace the U1, U8 circuits and the circuit board of the low-power electronic switch U9 (see Fig.13 ), the actual test shows that the output power of the RF electronic switch circuit is 46dBm, the power amplifier device can work normally, the insertion loss of the RF switch is less than 0.3dB, and the input and output isolation is greater than 40dB.

[0120] When testing the linearity and third-order intermodulation index of the power amplifier, two RF signals with a working frequency difference of 600KHz are input. The two input test signals with the same amplitude are synthesized into one through a three-way device and sent to the power amplifier baseband input port JD_ANT. The output power of the RF_ANT port is attenuated by 30dB through a directional coupler. When transmitting, the power of the two input signals is adjusted equally to increase to saturation. The output power amplitude of the two working RF signals is tested by a spectrum analyzer. When each channel reaches above 8.5dBm, the difference between the third-order intermodulation mixed signal and each working main frequency signal should be greater than 35dBc.

[0121] RF power amplifier device A receives the debugging equipment connection (see Fig.11 ), the debugging steps are as follows:

[0122] The JD_ANT_RX socket and the RF_ANT_RX socket of the RF power amplifier device A are short-circuited with a RF line, and the RF_ANT RF socket is input with a 650MHz, 0dBm RF signal from the E4432B signal source. When the PTT switch TX is set to a low-level receiving state, the output power of the JD_ANT RF port is tested with a spectrum analyzer to be -2.5dBm±0.3dB, and then the insertion loss of the power amplifier RF receiving channel is tested to be 2.5dB.

[0123] The RF power amplifier device A realizes the amplification of the RF power signal of the video transmission in the frequency band of 640-670 MHz and the switching of the receiving and transmitting channels. The communication transmission distance of the self-organizing network equipment using the RF power amplifier device A is increased by more than 10 times compared with the communication transmission distance of the self-organizing network transmission module alone. Through the power conversion and power amplifier control circuit A1, the open short circuit, over-current, over-temperature and over-power protection functions are realized, the receiving channel attenuation is small, and the transmitting channel has a high degree of harmonic and clutter suppression (see Figure 6 ); Through the RF power electronic switch circuit A2, high-power RF fast switching is achieved, and the switching time between sending and receiving is extremely short (see Figure 7 ); Through the power driving module circuit A3, the power linear amplification function of the power driving amplifier tube V1 and the final power driving amplifier tube V2 is realized (see Figure 8 ). Since it was put into use, the video transmission has been stable and reliable, with obvious practical effects. It is completely suitable for information communication between small-scale vehicle formations, and has won high praise from users. It meets the market demand for military and civilian dual-use information transmission and has broad application prospects.

[0124] The above description is only a preferred embodiment of the present invention. The above examples do not impose any form of limitation on the essential content of the present invention. Any simple modification or deformation made by ordinary technicians in the technical field to the above specific implementation methods based on the technical essence of the present invention after reading this specification, as well as equivalent embodiments that may be changed or modified to equivalent changes using the technical content disclosed above, still fall within the scope of the technical solution of the present invention without departing from the essence and scope of the present invention.

Claims

1. A radio frequency power amplification device for transmitting video in an ad hoc network, comprising an ad hoc network transmission module, an radio frequency power amplifier device (A), an LNA low noise amplifier box and a cavity filter, wherein the ad hoc network transmission module comprises a main video processing chip, an auxiliary video processing chip, frequency synthesis and up / down frequency conversion processing, and a radio frequency switch; the wired data signal received by the RJ45 network port terminal and the wireless signal received by the 2.4GHz antenna are sent to the main video processing chip for combination processing, the combined data are sent to the auxiliary video processing chip for data processing and digital-to-analog conversion to generate an analog radio frequency signal output, the radio frequency signal is sent to the radio frequency power amplifier device through BPF bandpass filtering, frequency synthesis down frequency conversion processing, power amplifier filtering and radio frequency switch; the signal received by the radio frequency power amplifier device is converted by the radio frequency switch, sent to the frequency synthesis up frequency conversion processing through low noise, and then sent to the auxiliary video processing chip after BPF bandpass filtering, the data signal after analog-to-digital conversion processing is finally sent to the main video processing chip for exchange and forwarding processing, the wired data is sent to the RJ45 network port terminal, and the wireless signal is transmitted through the 2.4GHz antenna, thereby completing the ad hoc network video transmission communication; Features: The transceiver control signal output end of the main video processing chip is connected to the transceiver control signal TX input pin of the radio frequency power amplifier device (A) through a wire, and the radio frequency power amplifier device (A) is composed of a power conversion and power amplifier control circuit (A1), an RF power electronic switch circuit (A2), a power drive module circuit (A3) and a device shell (A4); the radio frequency power amplifier device (A) is connected to the LNA low noise amplifier box through the device shell (A4); the device shell (A4) is composed of a shell (A40) and a heat sink (A41), and the circuit board of the power conversion and power amplifier control circuit (A1), the circuit board of the RF power electronic switch circuit (A2) and the circuit board of the power drive module circuit (A3) are respectively mounted on the heat sink (A41) and sealed and shielded by the shell (A40); The power conversion and power amplifier control circuit (A1) is composed of a micro single chip microcomputer (U5), a transmission control circuit (U3 / U4), a logarithmic forward detection circuit (U6), a logarithmic reverse detection circuit (U7), an overcurrent detection circuit (U18), an overtemperature detection circuit (U13 / U14), a PTT conversion circuit (U10), a power amplifier alarm circuit (U11) and a power supply voltage stabilization circuit (U15 / U16); the RF power electronic switch circuit (A2) is composed of a high-power radio frequency electronic switch (U1), a drive controller (U8), a low-power electronic switch (U9), an LC low-pass filter circuit and a circulator (Z1); the power drive module circuit (A3) is composed of a PA power amplifier circuit (V1 / V2), a baseband transceiver electronic switch (U2) and a low-power electronic switch (U12).

2. The RF power amplification device for transmitting video in an ad hoc network according to claim 1, characterized in that: The micro single chip microcomputer (U5) of the power conversion and power amplifier control circuit (A1) is used for four-way AD detection and comparison judgment output control; the transmission control circuit (U3 / U4) is composed of two field effect tubes U3 and U4 in cascade connection, and the alarm control output signal ALARM and RX_PTT jointly start the transmission control circuit (U3 / U4); the logarithmic forward detection circuit (U6) and the logarithmic reverse detection circuit (U7) are used for the forward and reverse detection of the transmission power standing wave, which is converted into a DC voltage by the logarithmic detector and sent to the micro single chip microcomputer (U5) of the power conversion and power amplifier control circuit (A1). The single-chip microcomputer (U5) performs analog-to-digital conversion and comparison processing, controls the on-off of the cascade of field effect tubes U3 and U4, and then completes the on-off control of the output power of the PA power amplifier circuit (V1 / V2) in the power drive module circuit (A3) together with the RX_PTT signal, and realizes the transmission start time of less than 2us; and when the open-circuit reflected power of the power amplifier output port is too large, it realizes the closed-loop control protection of the PA power amplifier circuit (V1 / V2); the power amplifier alarm circuit (U11) compares the four-way judgment output control The control ports are combined into one path as the power amplifier alarm output, and also as the protection control input signal of the transmission control circuit; the PTT conversion circuit (U10) inverts the TX control level for switching the receiving and transmitting channels and the electronic switch; the over-temperature detection circuit (U13 / U14) monitors the actual temperature of the RF power amplifier device (A), and outputs the converted analog voltage signal to the micro-chip microcomputer (U5) control circuit. When the temperature is too high, the power output of the PA power amplifier circuit (V1 / V2) is cut off; the over-current detection circuit (U18) monitors The RF power amplifier device (A) operates at a current, and the output converted analog voltage signal is sent to the control circuit of the micro single-chip computer (U5). When the current is too large, the power output of the PA power amplifier circuit (V1 / V2) is cut off; the power supply voltage regulator circuit (U15 / U16) steps down and stabilizes the 24V DC voltage twice to provide the required DC voltage for the RF power amplifier device (A); the power supply conversion and power amplifier control circuit (A1) realizes positive and negative standing waves, over-temperature, over-current detection, transmission power control, alarm output and linear voltage regulation functions.

3. The RF power amplification device for transmitting video in an ad hoc network according to claim 1, characterized in that: The high-power radio frequency electronic switch (U1) of the RF power electronic switch circuit (A2) realizes the switching of the transceiver channel. When the transceiver control signal TX is at a high level, the transmission channel power amplifier works, and when it is at a low level, the receiving channel works; the LC low-pass filter circuit is composed of inductors L4-L7 and capacitors C46-C48 to form a seven-level Butterworth filter; the circulator (Z1) is used for unidirectional transmission of radio frequency power, realizing isolation between the power amplifier output end and the load, and realizing reflected power detection during transmission; the RF power electronic switch circuit (A2) realizes the switching of the radio frequency front-stage transceiver channel and the detection of positive and negative standing wave input power.

4. The RF power amplification device for transmitting video in an ad hoc network according to claim 1, characterized in that: The PA power amplifier circuit (V1 / V2) of the power driving module circuit (A3) is mainly composed of a power driving amplifier tube (V1) and a final power driving amplifier tube (V2) to realize linear amplification of radio frequency power; the low-power electronic switch (U12) realizes further high isolation of the receiving channel from the transmitting signal to prevent the burning of the LNA low-noise amplifier; the baseband transceiver electronic switch (U2) realizes the independent switching processing function of one antenna port JD_ANT of the self-organizing network transmission module and two independent channels of power amplifier transceiver.

5. The RF power amplification device for transmitting video in an ad hoc network according to claim 1, characterized in that: The device housing (A4) is composed of a shell (A40) and a heat sink (A41); the power drive amplifier tube (V1) and the final power push amplifier tube (V2) of the PA power amplifier circuit (V1 / V2) of the power drive module circuit (A3) are directly mounted on the heat sink (A41); four radio frequency sockets, JD_ANT_RX, RF_ANT_RX, JD_ANT, and RF_ANT, are mounted on the shell (A40); The +24V, TX, GND, and Alarm signals are connected respectively through four through-hole capacitors of the outer shell (A40) to realize 24V DC voltage input, receiving and transmitting TX control signal input, grounding, and power amplifier alarm output; the JD_ANT_RX radio frequency socket and the RF_ANT_RX radio frequency socket are connected to the corresponding pins of the LNA low noise amplifier box; the JD_ANT port on the outer shell (A40) is connected to the antenna port JD_ANT of the self-organizing network transmission module, and the RF_ANT port of the device shell (A4) is connected to the antenna port of the self-organizing network device or the RF_ANT port of the cavity filter. The cavity filter is connected when the background noise and spectrum interference are serious, and is not connected otherwise.

6. The RF power amplification device for transmitting video in an ad hoc network according to claim 1, characterized in that: The radio frequency power amplifier device (A) has an operating frequency band of 640-670 MHz, and switches the receiving and transmitting channels through a high-power radio frequency electronic switch (U1); it is applicable to QPSK, BPSK, 16QAM, and 64QAM carrier modulation modes, and the transmitting channel power amplifier works when the receiving and transmitting control signal TX is at a high level, and the receiving channel works when the receiving and transmitting control signal TX is at a low level; the drain of the power driving amplifier tube (V1) and the final power driving amplifier tube (V2) are always powered, and the transmission start time is less than 2us by controlling the low voltage on and off of the gate bias; The average output power is 41.8dBm, the amplification gain is ≥24dB, the isolation of the RF power electronic switch at the output end of the power amplifier is ≥70dB, the in-band fluctuation is ≤1dB, the harmonic spurious suppression is above -80dBc, the third-order intermodulation is ≤-35dBc when the two channels are spaced 600kHz and the carrier power output of each channel is 38.8dBm, and it can work continuously for more than 24 hours.

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