High-efficiency variable gain E-type radio frequency power amplifier

Abstract

The invention discloses a high-efficiency variable gain E-type radio frequency power amplifier which comprises a controllable amplifier stage. The controllable amplifier stage is connected at an input end of an interstage matching circuit and is used for pre-expanding control of function and signal amplitude gain. The input end of the interstage matching circuit is connected with an output end of the controllable amplifier stage. An input end of an output amplifier stage is connected with a bias control circuit which is used for adjusting grid electrode bias voltage entering a switch transistor of the output amplifier stage. The input end of the output amplifier stage is connected with an output end of the bias control circuit through an inductor. According to the high-efficiency variable gain E-type radio frequency power amplifier, signal amplitude and a duty ratio control method are combined, and the purpose of control of output power of the nonlinear E-type power amplifier is achieved. Compared with an original E-type power amplifier power control method, output power range and output power efficiency are improved obviously.

Description

technical field [0001] The invention relates to a power amplifier, in particular to a class E radio frequency power amplifier with variable gain. Background technique [0002] Class E power amplifiers were first proposed by Sokal et al. in 1975. The basic structure of the circuit is as figure 1 As shown, it includes: switching transistor SW (usually MOS transistor can be used to drive its gate to realize the switching function), inductor L1 connected to the power supply voltage, capacitor C connected in parallel with the switching transistor, and inductors Ls and Cs that resonate in series at the operating frequency f0 , optimize the reactance element jX (usually inductance) and load impedance R. [0003] The working principle of class E power amplifier is as follows figure 1 As shown, when the input voltage is greater than the threshold voltage of the MOS transistor, the transistor works in the linear region, which is equivalent to the switch being closed. Since the resi...

AI Technical Summary

Problems solved by technology

However, in practical applications, it is difficult to provide such a variable power supply voltage, so it is necessary to add an LDO module when designing the circuit

Not only does the chip area increase, but also the LDO circuit has efficiency problems, and it needs to consume part of the power consumption, which leads to the reduction of the efficiency of the class E power amplifier in the entire power output range.

In addition to this method, there is no effective method for the realization of the power control function of the class E power amplifier with low power output.

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