RF Switching Module Series-Shunt Configuration for Insertion Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radio frequency (RF) switching systems face challenges in switching high voltage RF signals without distorting high frequencies at the load, particularly due to increased switch attenuation and insertion loss caused by off-state capacitance in inactive switches.
Innovation Solution
The implementation of RF switching modules with controllable elements such as n-type or p-type CMOS transistors, configured in series and shunt configurations, to manage high voltage loads and minimize off-state capacitance, thereby reducing insertion loss and maintaining low insertion loss during active switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If off-state capacitance is reduced to minimize insertion loss, then high frequency signal integrity is improved, but voltage loading capacity is reduced
Solution Approach 1:
The switching system is divided into multiple independent RF switching modules, each handling specific signal paths. This segmentation allows optimization of each module's transistor configuration to balance capacitance and voltage handling capabilities, reducing overall insertion loss while maintaining adequate voltage loading capacity across the system.
Solution Approach 2:
Different transistor configurations are applied to different switching modules based on their specific requirements. Series configurations are used where voltage loading capacity is critical, while shunt configurations are used where minimizing off-state capacitance is prioritized. This local optimization resolves the contradiction by allowing each component to be tuned for its specific function.
2Strength
If series configuration of transistors is used to increase voltage loading capacity, then breakdown voltage is improved, but off-state capacitance increases causing higher insertion loss
Solution Approach 1:
The voltage handling requirement is segmented across multiple transistor stages in series configuration. Each transistor handles a portion of the total voltage, allowing the use of smaller individual transistors with lower capacitance while collectively achieving the required breakdown voltage rating.
Solution Approach 2:
Asymmetric transistor sizing is employed within the series configuration, where transistors are sized differently to optimize the trade-off between voltage handling and capacitance. Larger transistors are placed where voltage stress is highest, while smaller transistors are used in stages with lower voltage requirements, minimizing overall off-state capacitance.
3Loss of energy
If shunt configuration of transistors is used to minimize off-state capacitance, then insertion loss is reduced, but voltage loading capacity decreases
Solution Approach 1:
Shunt configurations are selectively applied only in switching modules where minimizing off-state capacitance is the priority, such as modules handling lower voltage signals or where insertion loss is the dominant concern. This localized application maintains voltage loading capacity in critical paths while reducing capacitance where appropriate.
Solution Approach 2:
The design transitions from a single-dimensional approach (either series or shunt for all modules) to a multi-dimensional configuration space where different modules can operate in different configurations simultaneously. This allows the system to optimize for both voltage loading and capacitance minimization in different dimensions of the switching network.
Data Source
AI summary
Embodiments of radio frequency switching systems, modules, and methods with improved high frequency performance are described generally herein where the switching module may include a first switch module coupled in series to a second switch module, and a third switch module coupled between the first and the second module and ground. A controllable element of the second module may have a lower off capacitance than a controllable element of the first module. Other embodiments may be described and claimed.