Feedback Signal Calibration for Distortion Cancellation Circuits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing signal processing devices face challenges in accurately adjusting the amplitude and DC offset of feedback signals due to the aging and variability of variable resistors, leading to difficulties in extracting distortion components effectively.
Innovation Solution
A signal processing device with a subtractor, signal processing circuit, power amplifier circuit, A/D converter, offset adjuster, amplitude adjuster, delay adjuster, and calculator that use specific parameters determined by test signals to accurately adjust and extract distortion components, eliminating the need for variable resistors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a variable resistor is used to adjust the amplitude and DC offset of the feedback signal, then the adjustment can be made manually, but the resistance value shifts due to aged deterioration and vibration, making it difficult to accurately extract the distortion component
Solution Approach 1:
The patent replaces the mechanical variable resistor system with a digital signal processing system. The feedback signal passes through a digital amplifier circuit that applies gain based on stored correction values in a register, rather than using physical resistance adjustment. This substitution eliminates the mechanical wear and drift issues while maintaining adjustment capability through digital means.
Solution Approach 2:
The patent changes the adjustment parameter from physical resistance value to digital gain factor. The correction values are stored as digital parameters in a register, allowing precise control of the feedback signal amplitude and DC offset without the physical degradation associated with variable resistors. The digital parameters can be updated and maintained stably over time.
2Ease of operation
If manual adjustment of the variable resistor is performed, then the amplitude and DC offset can be adjusted, but the adjustment varies depending on the person making the adjustment
Solution Approach 1:
The patent implements an automatic adjustment system where the signal processing circuit automatically determines and applies the appropriate gain correction values. The system self-calibrates by comparing the feedback signal with the original input signal and automatically adjusting the digital gain parameters, eliminating human variability in the adjustment process while maintaining flexibility.
Solution Approach 2:
The patent uses feedback technology to automatically adjust the feedback signal parameters. The system continuously monitors the output signal, compares it with the input signal, and automatically modifies the digital gain values to achieve the desired signal characteristics, ensuring consistent and repeatable adjustments regardless of operator differences.
3Object-generated harmful factors
If feedback technology is used to extract distortion components, then distortion and noise can be reduced, but accurate extraction requires precise matching of amplitude and DC offset which is difficult to achieve with variable resistors
Solution Approach 1:
The patent replaces the mechanical variable resistor system with a digital signal processing system that uses digital amplification and correction. The feedback signal is processed through a digital amplifier circuit that applies precise gain factors stored in a register, enabling accurate matching of amplitude and DC offset without the physical limitations of resistance-based adjustment.
Solution Approach 2:
The patent implements a dynamic adjustment system where the gain correction values can be updated and modified. The digital parameters in the register can be changed to adapt to different operating conditions, allowing the system to maintain accurate signal matching across varying scenarios, unlike fixed or mechanically-drifting resistance values.
Data Source
AI summary
The signal processing device includes: an offset adjuster; an amplitude adjuster; and a delay adjuster, wherein the offset adjuster adjusts the DC offset using a first parameter regarding the DC offset determined based on an output of the offset adjuster which is output when no signal is input to the signal processing circuit by the subtractor, the amplitude adjuster adjusts the amplitude using a second parameter regarding the amplitude determined based on (i) an output of the amplitude adjuster which is output when a first test signal is input to the signal processing circuit and (ii) the first test signal, and the delay adjuster adjusts the delay using a third parameter regarding the delay determined based on the difference signal that is an output of the subtractor when a second test signal is input to the signal processing circuit.