Radio-frequency power amplifying circuit of high-power vehicle radio station

Abstract

The invention discloses a radio-frequency power amplifying circuit of a high-power vehicle radio station. According to the radio-frequency power amplifying circuit, a radio-frequency signal generated by a front pre-drive amplifier is transmitted into a drive amplifier through a drive power coupled impedance matching circuit to be amplified, output to a final-stage power amplifier through a drive tube load matching circuit to be amplified and then transmitted to an antenna terminal through a final-stage power amplifier output matching circuit; after the voltage of a VDD power supply is stabilized through a voltage stabilizing IC and the stabilized VDD is filtered through a first LC filter circuit, the stabilized and filtered VDD is fed to the drive amplifier. The VDD power supply is fed to the final-stage power amplifier after being filtered by a second filter circuit. Due to the fact that the voltage stabilized power supply is adopted for the drive amplifier, the final-stage power amplification can be high in stability, reliability and quality. Moreover, a high-frequency microwave high-power amplifying tube, the impedance matching circuit of the amplifying tube, and a matched base and a matched upper cover which are specially used for the high-frequency microwave high-power amplifying tube are effectively matched to replace the mode that corresponding power tubes are used for different frequency bands to carry out amplification, so that the impedance is matched at the optimum point, and thus the radio-frequency power amplifying circuit can achieve high-gain, high-linearity and high-efficiency radio-frequency power amplified output in the ultra-wide frequency band ranges of the UHF band, the VHF band and the HF band.

Description

technical field [0001] The invention relates to the technical field of wireless transmission, in particular to a radio frequency power amplifying circuit of a high-power vehicle radio. Background technique [0002] At present, the RF power amplifier circuits of high-power vehicle radios generally use discrete devices to do multi-stage amplification, because the gain of single-stage power cannot be very high, the performance index of the entire power amplification link and the final power amplification and promotion There is a great direct correlation between the two stages. In the traditional circuit, these two stages cannot be controlled by power supply. The two stages of the circuit are powered by direct power supply without control. The characteristics of the promotion stage have a great influence on the output power and radio frequency index The traditional circuit generally uses a high-power, high withstand voltage, and high-cost drive excitation tube; the other two sta...

AI Technical Summary

Problems solved by technology

[0002] At present, the RF power amplifier circuits of high-power vehicle radios generally use discrete devices to do multi-stage amplification, because the gain of single-stage power cannot be very high, the performance index of the entire power amplification link and the final power amplification and promotion There is a great direct correlation between the two stages. In the traditional circuit, these two stages cannot be controlled by power supply. The two stages of the circuit are powered by direct power supply without control. The characteristics of the promotion stage have a great influence on the output power and radio frequency index The traditional circuit generally uses a high-power, high withstand voltage, and high-cost drive excitation tube; the other two stages are directly controlled based on an APC control circuit, but the APC control is a hysteresis controller, which needs to be detected after the feedback In order to make the corresponding control, APC is a power standing wave detection circuit that cannot make any control and response to the power supply. When the power supply fluctuates greatly, although the output power can be controlled within the range, it will cause the final push to the power supply voltage fluctuation. The power input matching is completely unresponsive, which will cause over-excitation of the last-stage driving power when the power supply voltage is too high, and insufficient excitation of the final-stage driving power when the power supply voltage is too low, resulting in power output fluctuations of the final-stage power tube and final-stage power The working efficiency of the tube is seriously reduced, and it will cause damage to the power tube if it is serious.

[0003] Moreover, the selection of the power tube of the final power amplifier of the traditional vehicle radio is based on its frequency band and then the power amplifier tube of the corresponding frequency band is used for power output, and the matching circuit design is carried out with reference to the parameters of the power tube or power module. Such as VHF frequency band power amplification, using the corresponding power tube of VHF band and the matching parameters of this tube, UHF band power amplification, using the corresponding power tube of UHF band and the matching parameters of this tube; the radio frequency power amplification using this scheme Under the condition of the limit parameters of the power tube, the circuit cannot achieve the ideal power output characteristics in the wide frequency range, that is, the linear amplification of the wide frequency band cannot be achieved in the full frequency range, and the amplification gain varies greatly with the operating frequency, resulting in power The output flatness is extremely poor, and the efficiency also varies with a wide range. It is mainly manifested in the output attenuation and poor efficiency when the power is amplified at high frequencies. When the power is amplified at low frequencies, the parameter changes during the output will cause the impedance matching to be not at the optimal point, and the same cannot be achieved. Achieve proper output power and efficiency

This conventional type of power amplifier tube and circuit obviously cannot meet the requirements of the current wide-band vehicle radio

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