RF Switch Linearization Using Asymmetric Anti-Series Varactor Pairs
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radio-frequency (RF) switches suffer from significant second and third-order distortions due to the non-linear behavior of field-effect transistors, which affect switching performance and signal integrity.
Innovation Solution
Incorporation of asymmetrical anti-series varactor pairs in parallel with the shunt arm of RF switches, configured to reduce both second and third-order distortions by offsetting the non-linearities of field-effect transistors through tailored varactor widths and asymmetry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional RF switch with field-effect transistors is used, then the switch can perform basic signal routing, but second and third order distortions are generated that degrade performance
Solution Approach 1:
A varactor stack is introduced as an intermediary component coupled in parallel to the shunt arm. The varactor stack acts as a mediator that generates opposing nonlinearities to cancel the distortions produced by the field-effect transistors, thereby reducing second and third order distortions without compromising switching performance
Solution Approach 2:
The patent employs an asymmetric anti-series varactor pair configuration where the two varactors have different dimensions (different widths). This asymmetry is deliberately designed to generate specific nonlinear characteristics that counterbalance the distortion profile of the field-effect transistors, enabling simultaneous reduction of both second and third order distortions
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
Simultaneously reduces both second and third-order harmonics, improving RF switch performance by minimizing distortions and enhancing signal quality.
Implementation Method 1
a varactor stack comprising an asymmetric anti-series varactor pair, the varactor stack coupled in parallel to the shunt arm between the series arm and the reference potential node, the varactor stack configured to simultaneously reduce second order distortions and third order distortions generated by the set of field-effect transistors in the shunt arm
Data Source
AI summary
Described herein are switches with asymmetrical anti-series varactor pairs to improve switching performance. The disclosed switches can include asymmetrical varactor pairs to reduce distortions. The asymmetry in the varactor pairs can be associated with geometry of each varactor in the pair. The disclosed switches can stack both symmetrical and asymmetrical varactor pairs. The disclosed switches with asymmetrical anti-series varactor pairs can be configured to improve both H2 and H3 simultaneously.