Adaptive Bias Impedance Circuit for Amplifier Linearity
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Solution Overview
Problem
Amplifier devices face limitations in power usage due to non-linear power-gain and power-phase curves, and the complexity of circuit design increases when trying to improve linearity, which varies with input signal, voltage source, and temperature.
Innovation Solution
An amplifier device with a variable impedance unit and a bias module that adjusts linearity based on frequency, voltage, and temperature, using a power element and bias elements to provide a bias voltage and adjust impedance values according to input signal power and operation mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the power of amplifier device is reduced to improve linearity, then the linearity is improved, but the power usage efficiency deteriorates
Solution Approach 1:
The patent applies dynamics by making the impedance value adjustable rather than fixed. The impedance unit's impedance value can be dynamically changed based on operating conditions (frequency, voltage, temperature) to maintain optimal linearity across different power levels, thus resolving the contradiction between linearity and power usage efficiency.
Solution Approach 2:
The patent changes the impedance parameter of the impedance unit to optimize amplifier performance. By adjusting the impedance value according to frequency, voltage, or temperature conditions, the amplifier maintains better linearity without requiring power reduction, thereby improving both linearity and power usage efficiency simultaneously.
2Manufacturing precision
If a pre-distortion circuit is introduced to improve linearity, then the linearity is improved, but the circuit complexity increases
Solution Approach 1:
The patent introduces an impedance unit as an intermediary component between the voltage source and the amplifying unit. This impedance unit acts as a mediator that adjusts the bias conditions to improve linearity, avoiding the need for complex pre-distortion circuits while achieving the desired linearity improvement.
Solution Approach 2:
Instead of using complex pre-distortion circuits, the patent simplifies the approach by changing the impedance parameter of the impedance unit. This single parameter adjustment (impedance value) can be controlled based on frequency, voltage, or temperature to achieve linearity improvement with minimal circuit complexity.
3Manufacturing precision
If different control factors are considered for pre-distortion circuit, then the linearity under different conditions is improved, but the circuit complexity increases
Solution Approach 1:
The impedance unit serves multiple functions: it can be controlled by frequency, voltage, or temperature depending on the operating conditions. This multi-functional capability allows the same simple circuit structure to handle different control factors (frequency variations, voltage variations, temperature variations) without increasing complexity, thus achieving universal linearity improvement across different conditions.
Data Source
AI summary
An amplifier device includes an amplifying unit, a bias module and an impedance unit. A first end of the amplifying unit electronically connects to a voltage source. A second end of the amplifying unit receives an input signal. The first end of the amplifying unit outputs an output signal amplified by the amplifying unit. A third end of the amplifying unit connects to a first reference potential. The bias module electrically connects to the second end of the amplifying unit for providing a bias voltage to the amplifying unit. An impedance unit is electrically connects to the bias module. An impedance value of the impedance unit is variable. The bias module adjusts the amplifier's linearity according to a frequency value of the input signal, a voltage value of the voltage source or a temperature value of the amplifier device. The impedance is adjusted according to the above-mentioned values.