Compensation circuit of amplitude modulation-phase modulation, radio frequency power amplifier and device
View Patent ↗An amplitude modulation-phase modulation compensation circuit includes a detection circuit, a reconfigurable current control voltage source circuit and a phase shifting circuit, in which, the detection circuit is configured to detect the power of an input signal and output a control current according to the power of the input signal when the power of the input signal is greater than a preset power threshold; the reconfigurable current control voltage source circuit is configured to generate a bias voltage according to the control current; the phase shifting circuit is configured to compensate the AM-PM distortion of the radio frequency power amplifier according to the bias voltage. In this way, by the compensation circuit, when the power of the input signal is greater than a preset power threshold, the AM-PM distortion of the radio frequency power amplifier can be compensated according to the power of the input signal.
1 . A compensation circuit of amplitude modulation-phase modulation of a radio frequency power amplifier, comprising a detection circuit, a reconfigurable current control voltage source circuit, and a phase shifting circuit, wherein
the detection circuit is configured to detect a power of an input signal and output a control current to the reconfigurable current control voltage source circuit according to the power of the input signal when the power of the input signal is greater than a preset power threshold that is adjustable and represents a power point at which compensation is turned on;
the reconfigurable current control voltage source circuit is configured to generate a bias voltage according to the control current; and
the phase shifting circuit is configured to compensate an amplitude modulation-phase modulation AM-PM distortion of the radio frequency power amplifier according to the bias voltage;
wherein the detection circuit is configured to only detect the power of the input signal but not output the control current when the power of the input signal does not reach the preset power threshold; and
wherein when the power of the input signal is equal to the preset power threshold, the compensation is turned on, while the control current equals 0.
2 . The compensation circuit of claim 1 , wherein
the compensation circuit further comprises a first control voltage source, which is connected with the detection circuit;
the first control voltage source is configured to output a first control voltage; and
the detection circuit is further configured to adjust the preset power threshold according to the first control voltage.
3 . The compensation circuit of claim 1 , wherein
the compensation circuit further comprises a second control voltage source, which is connected with the reconfigurable current control voltage source circuit;
the second control voltage source is configured to output a second control voltage and a third control voltage; and
the reconfigurable current control voltage source circuit is further configured to control a corresponding relationship between the bias voltage and the control current according to the second control voltage and the third control voltage.
4 . The compensation circuit of claim 3 , wherein
the corresponding relationship comprises an increasing function relationship or a decreasing function relationship; wherein the increasing function relationship indicates that the bias voltage increases with an increase of the control current, and the decreasing function relationship indicates that the bias voltage decreases with the increase of the control current.
5 . The compensation circuit of claim 4 , wherein
the reconfigurable current control voltage source circuit comprises a first transistor group and a second transistor group, and both the first transistor group and the second transistor group comprise multiple switching transistors;
the reconfigurable current control voltage source circuit is specifically configured to control that the bias voltage and the control current have the increasing function relationship when the first transistor group is controlled to turn on according to the second control voltage and the second transistor group is controlled to turn off according to the third control voltage; or,
the reconfigurable current control voltage source circuit is specifically configured to control that the bias voltage and the control current have the decreasing function relationship when the first transistor group is controlled to turn off according to the second control voltage and the second transistor group is controlled to turn on according to the third control voltage.
6 . The compensation circuit of claim 1 , wherein
the reconfigurable current control voltage source circuit comprises a variable resistor; and
the reconfigurable current control voltage source circuit is configured to adjust a compensation degree of the compensation circuit to the AM-PM distortion of the radio frequency power amplifier by adjusting a resistance of the variable resistor.
7 . The compensation circuit of claim 1 , wherein
the reconfigurable current control voltage source circuit comprises at least one current mirror module which is composed of two transistors; and
the reconfigurable current control voltage source circuit is configured to adjust the compensation degree of the compensation circuit to the AM-PM distortion of the radio frequency power amplifier by adjusting an area ratio of the current mirror module.
8 . The compensation circuit of claim 1 , wherein
the phase shifting circuit comprises a phase shifting transistor; and
the phase shifting circuit is specifically configured to adjust an equivalent capacitance of the phase shifting transistor according to the bias voltage and compensate the AM-PM distortion of the radio frequency power amplifier according to the equivalent capacitance.
9 . A radio frequency power amplifier, comprising the compensation circuit of claim 1 .
10 . The radio frequency power amplifier of claim 9 , wherein
the radio frequency power amplifier further comprises a bias circuit and an amplification circuit, and both the compensation circuit and the bias circuit are connected with a signal input end of the amplification circuit;
the compensation circuit is configured to compensate the AM-PM distortion of the radio frequency power amplifier based on the input signal, to obtain a compensated input signal;
the bias circuit is configured to provide a bias current for the amplification circuit; and
the amplification circuit is configured to power amplify the compensated input signal based on the bias current.
11 . The radio frequency power amplifier of claim 9 , wherein
the amplification circuit comprises one amplification transistor; or,
the amplification circuit comprises multiple amplification transistors, which form a stacked tube structure.
12 . The radio frequency power amplifier of claim 9 , wherein
the detection circuit, the reconfigurable current control voltage source circuit and the phase shifting circuit are cooperatively operated such that when the power of the input signal is greater than the preset power threshold, the AM-PM distortion of the radio frequency power amplifier is compensated according to the power of the input signal, thereby reducing the AM-PM distortion generated during signal amplification, and improving signal quality and ACLR performance of the radio frequency power amplifier.
13 . An electronic device, comprising the radio frequency power amplifier of claim 9 .