Gain control method for radio frequency power amplifier

Abstract

The invention provides a gain control method for a radio frequency power amplifier. A gain control unit is concatenated before radio frequency signals are inputted to a matching network and provides at least two different radio frequency passages, and each radio frequency passage has different damping capacities for the radio frequency signals. Generally, impedance inputted and outputted by each radio frequency passage is matched with radio frequency system characteristic impedance, the gain control unit provides different radio frequency damping capacities in different gain/power modes, the input and output impedance states of the gain control unit remain unchanged in different damping capacity states, the working states of active devices in the radio frequency power amplifier constantly remain unchanged, so that phase characteristics and linearity remain unchanged, the input and output impedance states of the radio frequency power amplifier in different gain/power modes also remain unchanged, and the impedance of the radio frequency power amplifier is matched with that of a radio frequency transceiver, so that performance consistency of the radio frequency power amplifier and a whole radio frequency front end system is furthest ensured.

Description

technical field [0001] The invention relates to a gain control method for a front end of a radio frequency system, in particular to a gain control method for a radio frequency power amplifier, and belongs to the technical field of radio frequency front ends. Background technique [0002] In modern wireless communication systems, the RF front-end is a key component to realize the wireless transmission of RF signals; the RF power amplifier is an important part of the RF front-end, which realizes the power amplification of RF signals. Usually, the input signal of the RF power amplifier comes from the RF transceiver in the system, and the RF signal is amplified by the RF power amplifier and sent to the antenna port for transmission. Depending on the distance between the receiver and the transmitter, that is, the strength of the signal that can be received at the location of the receiver is different, the wireless communication system usually needs to dynamically control the outp...

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to overcome the current by changing the bias voltage Vbias The value controls the RF front-end channel gain, resulting in impedance mismatch between the RF power amplifier and the RF transceiver, and the disadvantages of the linearity index of the RF power amplifier changing with the gain

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