E type power amplifier digital power control circuit applied on low power output

Abstract

The invention discloses a digital power control circuit, which is applied to an class E power amplifier with low power output, and comprises a stage matching circuit and an output amplifier stage, wherein, the stage matching circuit is used for effective cascade of an amplifier, and the output amplifier stage is used for amplifying signal power. An output terminal of the stage matching circuit is connected with an input terminal of the output amplifier stage; a controllable amplifier stage used for pre-magnification function and signal amplitude gain control is connected with the input terminal of the stage matching circuit, and the input terminal of the stage matching circuit is connected with the output terminal of the controllable amplifier stage; the input terminal of the output amplifier stage is connected with a bias control circuit used for adjusting the grid bias voltage entering a switching transistor of the output amplifier stage; and the input terminal of the output amplifier stage is connected with the output terminal of the bias control circuit through an inductor. The digital power control circuit increases the output power range and output power efficiency, and has the advantages of simple and reliable circuit organization and easy integration of monolithic circuits.

Description

technical field [0001] The invention relates to an amplifier output power control circuit, in particular to an output power control circuit of a class E power amplifier with low power output. 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 resonant in series at the operating frequency f 0 The inductance L s with C s , optimize the reactance element jX (usually inductance) and load impedance R. [0003] The working principle of the 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...

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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