Piecewise Conductance Network for RF Switch IMD3 Cancellation
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Solution Overview
Problem
Radio frequency (RF) switch devices introduce third-order intermodulation distortion (IMD3) when closing, which is difficult to filter out due to the proximity of RF frequency bands, especially in composite RF signals.
Innovation Solution
A conductance network is connected in parallel with the RF switch, generating a third-order resonant response with the same magnitude but opposite phase to cancel out IMD3 resonant vibrations without requiring an RF filter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an RF filter is used to remove third-order intermodulation distortion, then signal quality is improved, but device complexity and insertion loss increase
Solution Approach 1:
The patent converts the harmful third-order resonant vibrations generated by the RF switch into a beneficial cancellation mechanism. By deliberately generating IMD3-resonant vibrations with opposite phase through a conductance network, the harmful vibrations are neutralized, transforming the problem into a solution without requiring external filtering components.
Solution Approach 2:
The conductance network acts as an intermediary element between the RF switch and the output. It generates compensating vibrations that mediate the interaction between the switch-generated distortion and the desired RF signal, enabling distortion cancellation without direct mechanical or electrical filtering of the harmful components.
2Measurement precision
If an RF filter is used to remove third-order intermodulation distortion, then signal quality is improved, but insertion loss increases
Solution Approach 1:
Instead of using an RF filter that would attenuate both the desired signal and the distortion (causing insertion loss), the patent converts the distortion into a beneficial cancellation mechanism. The conductance network generates vibrations that actively neutralize the harmful IMD3, preserving signal energy while removing distortion.
3Adaptability or versatility
If the conductance network operates over a wide power range, then adaptability is improved, but temperature sensitivity increases
Solution Approach 1:
The patent employs parameter changes by utilizing the voltage-dependent conductance characteristics of the diode-connected transistors. By adjusting bias voltages applied to the gates of these transistors, the conductance network can be tuned to maintain optimal cancellation performance across different power levels and temperature conditions, thereby improving adaptability while managing temperature sensitivity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The conductance network effectively cancels IMD3 resonant vibrations, providing wider power range and reduced temperature sensitivity, improving RF signal quality.
Implementation Method 1
the conductance network has an impedance with a frequency response with a same magnitude as the IMD3 resonant vibrations but with an opposite phase
Implementation Method 2
generating a third-order resonant response with the same magnitude but opposite phase to cancel out IMD3 resonant vibrations
Data Source
AI summary
A conductance network is disclosed for switching circuitry. In some embodiments, the conductance network includes a first conductance stage and a second conductance stage. The first conductance stage is configured to define a first voltage-to-current response such that the first voltage-to-current response defines a first deadband region between a first pair of quasi-quadratic or quasi-linear regions. The second conductance stage is configured to define a second voltage-to-current response such that the second voltage-to-current response defines a second deadband region between a second pair of quasi-quadratic or quasi-linear regions, wherein the second deadband region is wider than the first deadband region.