Signal Amplification Circuit for Dual-Domain Distortion Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional radio frequency signal transmitters suffer from nonlinear distortion and background noise amplification in power amplifiers, leading to signal distortion.
Innovation Solution
A signal amplification circuit comprising a signal amplification sub-circuit, first and second signal extraction sub-circuits, and a distorted signal cancellation sub-circuit, which sequentially perform digital-to-analog conversion, amplitude and phase modulation, and analog-to-digital conversion to extract and cancel distorted signals in both the analog and digital domains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If power amplification is performed on the signal, then the signal power is increased, but nonlinear distortion and background noise are amplified
Solution Approach 1:
The patent extracts the distorted signal from the power-amplified signal by performing amplitude modulation and phase modulation on a copy of the input signal, then combining it with the power-amplified signal. This separation allows the distorted component to be identified and cancelled independently from the useful signal.
Solution Approach 2:
The patent converts the harmful distorted signal into a useful cancellation component by generating a corrected signal that is equal in magnitude but opposite in phase to the distorted signal. This corrected signal is then added to the power-amplified signal to cancel out the distortion and background noise.
2Device complexity
If only analog domain processing is used, then the circuit structure is simple, but the distortion cancellation precision is insufficient
Solution Approach 1:
The patent divides the distortion cancellation process into two distinct domains: analog domain processing for initial distortion extraction and cancellation, and digital domain processing for residual distortion cancellation. This segmentation allows each domain to be optimized for its specific function, achieving both simplicity and precision.
Solution Approach 2:
The patent transitions from purely analog processing to a hybrid analog-digital approach by introducing digital signal processing for the second stage of distortion cancellation. This dimensional change from analog to digital domain enables higher precision cancellation of residual distortions that remain after analog processing.
3Reliability
If multiple signal extraction stages are implemented, then distortion cancellation effectiveness is improved, but the device complexity increases
Solution Approach 1:
The patent implements two sequential signal extraction stages: first in the analog domain and then in the digital domain. Each stage targets different components of the distortion, with the first stage handling the primary distortion and the second stage addressing residual distortions. This segmented approach improves overall cancellation effectiveness while keeping each individual stage relatively simple.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
This application discloses a signal amplification circuit and method, and a signal transmitter, and belongs to the field of electronic technologies. Digital-to-analog conversion and power amplification are performed on a first digital signal to obtain a first analog signal; a distorted signal in the first analog signal is extracted in an analog domain and a digital domain separately; and the extracted distorted signal is coupled to the first analog signal to obtain an output signal. Because the signal amplification circuit can successively extract the distorted signal in the analog domain and the digital domain, it can be ensured that a residual of a main signal in the extracted distorted signal is small. Therefore, it can be ensured that after the distorted signal is coupled to the first analog signal, the distorted signal in the first analog signal can be effectively cancelled, thereby effectively improving linearity of the output signal that is finally output.