Switching Device Phase Shifting Modes Reduce Intermodulation Distortion
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Solution Overview
Problem
Conventional high-frequency switching devices face challenges in reducing intermodulation distortion (IMD) without increasing semiconductor die area or signal loss, and existing methods to mitigate IMD either increase cost or require complex technology.
Innovation Solution
A switching device with selectable phase shifting modes, utilizing phase shifting switching branches with transmission lines and FETs to adjust phase shift, allowing for optimal attenuation of out-of-band blocker signals and reduced IMD3 performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the number of FETs in each switching arm is increased to reduce IMD, then intermodulation distortion is reduced, but semiconductor die area and signal loss increase
Solution Approach 1:
The patent implements dynamic switching between different FET configurations (single FET mode and parallel FET mode) based on operating conditions. The switching controller dynamically selects which FETs are active, allowing the system to adapt to different signal conditions and reduce IMD only when necessary, rather than permanently using more FETs which would increase die area.
Solution Approach 2:
The patent changes the electrical parameters (conductivity state) of existing FETs dynamically by controlling their switching states. By changing the conductivity of individual FETs within the switching arm based on detected signal conditions, the system can reduce IMD without adding more physical FETs to the circuit.
2Object-generated harmful factors
If a charge pump is utilized to increase the high voltage for enabling switching arms to reduce IMD, then intermodulation distortion is reduced, but device cost increases
Solution Approach 1:
The system uses its own output signal to detect blocking signals and control the switching states of FETs. The switching controller monitors the signal conditions and automatically adjusts the FET configurations without requiring external voltage boosting equipment like charge pumps, making the system self-regulating and cost-effective.
Solution Approach 2:
The patent extracts and removes the charge pump component from the system entirely. Instead of using external voltage boosting equipment to reduce IMD, the invention uses the existing FET switching mechanism with intelligent control based on signal detection, eliminating the need for additional expensive components.
3Object-generated harmful factors
If the number of FETs in each switching arm is increased to reduce IMD, then intermodulation distortion is reduced, but signal loss increases
Solution Approach 1:
The system dynamically adjusts the number of active FETs based on real-time signal conditions. When blocking signals are detected that would cause IMD, the controller activates additional FETs in parallel mode. When such conditions are absent, the system operates with fewer FETs active, minimizing signal loss while maintaining adequate IMD performance.
Data Source
AI summary
According to one exemplary embodiment, a switching device with phase selection terminals to select between at least two phase shifting modes to reduce intermodulation distortion in the switching device includes a first phase selection terminal to select a first phase shifting mode of the switching device by enabling a first transmission line in a first phase shifting switching branch coupled to an input of the switching device. The switching device further includes a second phase selection terminal to select a second phase shifting mode of the switching device by enabling a second phase shifting switching branch coupled to the switching device input. The intermodulation distortion in the switching device is reduced by selecting one of the first and second phase shifting modes. The first transmission line is enabled by enabling a FET coupled in series with the first transmission line in the first phase shifting switching branch.