RF power amplifier circuit and RF transmitter

Abstract

A radio frequency power amplifier circuit and a radio frequency transmitter, the radio frequency power amplifier circuit includes: a variable current source, a load circuit and a power amplifier, wherein: the variable current source is coupled to the load circuit; the load circuit includes a first A resistor, a second resistor, a nonlinear device, and a first zener diode, the first end of the first resistor is coupled to the output end of the variable current source, and the second end is coupled to the anode of the first zener diode ; The first end of the second resistor is coupled to the output end of the variable current source, and the second end is coupled to the first end of the nonlinear device; the second end of the nonlinear device is coupled to the anode of the first Zener diode ; The cathode of the first Zener diode is coupled to the ground; the first input terminal of the power amplifier is coupled to the output terminal of the load circuit, and the second input terminal inputs the radio frequency signal to be sent. The scheme can slow down the change speed of the input voltage of the power amplifier, thereby reducing the spectrum leakage during the switching process of the power amplifier.

Description

technical field [0001] The invention relates to the field of radio frequency communication, in particular to a radio frequency power amplifier circuit and a radio frequency transmitter. Background technique [0002] In modern wireless radio frequency communication technology, a power amplifier (Power Amplifier, PA) is a device that amplifies the power of a signal to be transmitted, and is an essential device in a radio frequency transmitter. When the power amplifier is turned on or off, if the power changes too fast, interference signals of other frequency points will appear on the transmission spectrum of the power amplifier, which will affect the normal operation of other devices and reduce the performance of the entire communication system. [0003] refer to figure 1 , gives a schematic structural diagram of an existing load circuit at the input end of a power amplifier, including a variable current source and a load resistor R 1 . The output current of the variable cu...

AI Technical Summary

Problems solved by technology

[0004] However, from figure 2 It can be seen from the figure that although Vramp has achieved slow change as a whole, the change speed of Vramp is still relatively fast, resulting in a faster turn-on and turn-off speed of the power amplifier, resulting in spectrum leakage

Images