RF Power Amplifier Current Feedback for Stable Gain and Output
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The gain and output power of radio frequency power amplifiers are unstable due to process deviations and temperature variations, leading to variations in quiescent operating currents and input signal amplitudes, necessitating feedback control to maintain stable gain and output power.
Innovation Solution
A radio frequency power amplifier with multiple stages of amplifier circuits, incorporating current and power detection feedback circuits that adjust quiescent operating currents and output power to stabilize gain and output power by detecting and correcting variations through feedback loops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If feedback control is implemented to stabilize gain and output power, then stability of gain and output power is improved, but device complexity increases due to additional detection feedback circuits
Solution Approach 1:
The patent implements feedback control by detecting the quiescent operating current of the current stage amplifier circuit and feeding back a control signal to adjust the quiescent operating current of previous stage amplifier circuits. This feedback mechanism stabilizes the gain and output power against variations caused by process deviations and temperature changes, directly resolving the technical contradiction by prioritizing stability while managing the added circuit complexity.
2Manufacturing precision
If detection feedback circuits are added to control quiescent operating current, then manufacturing precision of gain and output power is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical or manual adjustment mechanisms with electronic detection and feedback circuits that automatically sense and correct variations in quiescent operating current. This substitution achieves precise control of gain and output power through electronic means, improving manufacturing precision while the added electronic circuitry is managed within acceptable complexity limits.
3Power
If multiple stages of amplifier circuits are used to achieve required gain, then power amplification capability is improved, but stability deteriorates due to cumulative variations in quiescent operating current
Solution Approach 1:
The patent applies feedback control specifically targeted at stabilizing the quiescent operating current of each stage in the multi-stage amplifier. By detecting and correcting current variations at each stage, the system maintains stable gain across multiple amplifier stages, enabling high power amplification capability without suffering from cumulative stability degradation.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed in the present invention are a radio frequency power amplifier based on current detection feedback, a chip, and a communication terminal. The radio frequency power amplifier comprises multiple stages of amplifier circuits and at least one current detection feedback circuit; the input end of the current detection feedback circuit is connected to the input end of a current stage of amplifier circuit among the multiple stages of amplifier circuits by means of a corresponding resistor, and the output end of the current detection feedback circuit is connected to the input end of at least one stage of amplifier circuit prior to the current stage of amplifier circuit. The current detection feedback circuit generates, according to the detected quiescent operating current of the current stage of amplifier circuit, a control voltage varying inversely with the quiescent operating current, so that the current detection feedback circuit outputs current varying positively with the control voltage. The current is input to the input end of the at least one stage of amplifier circuit prior to the current stage of amplifier circuit, and the quiescent operating current of the at least one stage of amplifier circuit prior to the current stage of amplifier circuit is controlled, so that the radio frequency power amplifier operates in a state in which the gain and the output power are stable.