Feedforward Amplifier Circuit With Simplified Distortion Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing feedforward amplifier circuits require cumbersome processes for selecting circuit component parameters, leading to complex structures and high costs due to dependence on open-loop frequency-amplitude characteristics and feedback loops of the main amplifier.
Innovation Solution
A simplified feedforward amplifier circuit design using a main amplifier, adder, sub-amplifier, and subtractor circuit, where the main amplifier adds distortion to a signal, which is corrected through feedforward by the sub-amplifier and subtractor, with the adder combining signals to output a distortion-free signal, reducing dependence on the main amplifier's feedback loop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing feedforward amplifier circuits use traditional component selection methods based on open-loop frequency-amplitude characteristics and feedback loops, then distortion correction can be achieved, but the component selection process becomes cumbersome and the circuit structure becomes complex
Solution Approach 1:
The patent extracts the feedforward correction function from the traditional feedback-dependent architecture by introducing an independent subtractor circuit that directly processes the distorted signal. This separation allows distortion correction to be achieved without relying on the main amplifier's feedback loop, thereby simplifying component selection and reducing circuit complexity while maintaining correction effectiveness
Solution Approach 2:
The circuit is segmented into distinct functional modules: the main amplifier circuit for signal amplification, the subtractor circuit for distortion signal extraction and reverse amplification, and the adder circuit for signal combination. This modular segmentation enables independent optimization of each module and simplifies the overall design process by eliminating the need for complex inter-dependent component matching
2Reliability
If existing feedforward amplifier circuits use traditional component selection methods, then distortion correction is possible, but the selected target circuit components become costly
Solution Approach 1:
The patent employs standard, readily available operational amplifiers and passive components in the feedforward correction path rather than requiring specialized expensive components. The subtractor and adder circuits use conventional op-amps with standard feedback networks, making the circuit economical to manufacture while still achieving effective distortion suppression
Solution Approach 2:
The patent changes the design approach from parameter-matching-based component selection to a topology-based design where component values are determined by simple gain requirements rather than complex frequency-response matching. This allows the use of standard component value series and reduces the need for expensive precision components
3Device complexity
If the circuit structure is simplified by reducing dependence on the main amplifier's feedback loop, then component selection becomes easier and costs are reduced, but the distortion correction effectiveness must be maintained
Solution Approach 1:
While reducing dependence on the main amplifier's feedback loop, the patent introduces local feedback paths in the subtractor and adder circuits to ensure stable operation and maintain correction effectiveness. The sub-amplifier's feedback loop provides local stability, and the overall feedback structure ensures that the feedforward correction operates effectively across the desired frequency range
Data Source
AI summary
Provided are feedforward amplifier circuit, audio amplifier and audio playing device, including: a main amplifier circuit, an adder circuit, a sub-amplifier circuit and a subtractor circuit, wherein the main amplifier circuit adds distortion to a first input signal to output a distorted signal, and inputs the distorted signal to the adder circuit and the subtractor circuit for performing feedforward correction; the sub-amplifier circuit amplifies a second input signal and serves as a positive input of the subtractor, so that a signal gain output by the subtractor is equal to a signal gain of the main amplifier; the subtractor circuit, with the distorted signal as a negative input, reversely amplifies the distorted signal and afterwards performs feedforward; and the adder circuit superimposes the distorted signal output by the main amplifier circuit and the reversely amplified distorted signal output by the subtractor, so as to output a distortion-free signal.