RF Switch Device with Shared Primary Transistors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing single-pole multi-throw switches face challenges in reducing parasitic capacitance and required area, especially in wireless communication systems, which affects signal transmission strength and conflicts with the needs of mobile electronic devices as the number of selection circuits increases.
Innovation Solution
The proposed switch device incorporates a selection circuit with a primary switch and two secondary switches, each with multiple transistors in series, sharing primary transistors to reduce circuit area and parasitic capacitance, and using control signals to manage transistor states effectively, allowing for efficient radio frequency signal transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of selection circuits is increased to provide more transmission paths, then the adaptability of the switch device is improved, but the required area and parasitic capacitance increase significantly
Solution Approach 1:
The patent merges multiple selection circuits by having them share common primary transistors. Specifically, multiple selection circuits share a set of primary transistors connected to the common terminal, reducing the total number of transistors needed. This combining approach allows the switch to provide multiple transmission paths while significantly reducing the required circuit area compared to having completely separate selection circuits for each path.
Solution Approach 2:
The primary transistors serve multiple functions by being shared across different selection circuits. Each primary transistor can be part of multiple transmission paths depending on which secondary transistors are activated, making the primary transistor layer universal and adaptable to different switching configurations without requiring dedicated transistors for each path.
2Adaptability or versatility
If the number of selection circuits is increased to provide more transmission paths, then the adaptability of the switch device is improved, but the parasitic capacitance increases which weakens signal transmission
Solution Approach 1:
By merging selection circuits to share primary transistors, the total number of transistors in the switch device is reduced. Since each transistor contributes parasitic capacitance, reducing the total transistor count directly reduces the overall parasitic capacitance. This allows multiple transmission paths to be provided while keeping parasitic effects manageable and signal transmission strength adequate.
3Adaptability or versatility
If more selection circuits are added to the single-pole multi-throw switch, then the versatility is improved, but the device complexity and required area increase significantly
Solution Approach 1:
The patent reduces device complexity by merging selection circuits through shared primary transistors. Instead of having N separate selection circuits each with their own set of transistors, the design uses a shared primary transistor layer that serves multiple selection circuits. This hierarchical sharing structure significantly reduces the total component count and interconnections, making the device less complex while maintaining versatility.
4Strength
If the number of transistors in each selection circuit is increased to improve signal transmission, then the transmission strength is improved, but the parasitic capacitance and required area increase
Solution Approach 1:
The patent achieves adequate signal transmission strength by merging selection circuits so that primary transistors are shared across multiple circuits. This sharing reduces the total number of transistors needed in the entire switch device, thereby reducing total parasitic capacitance while still providing multiple transmission paths with sufficient signal strength through the shared primary transistor infrastructure.
Data Source
AI summary
A switch device includes a common terminal and a selection circuit. The selection circuit includes a primary switch, a first secondary switch, and a second secondary switch. The primary switch includes a plurality of primary transistors coupled in series and is coupled to the common terminal. The first secondary switch is coupled to the primary switch and a first transmission terminal. The first secondary switch includes a plurality of first secondary transistors coupled in series. The second secondary switch is coupled to the primary switch and a second transmission terminal. The second secondary switch includes a plurality of second secondary transistors coupled in series. The number of the first secondary transistors and the number of the second secondary transistors are both greater than or equal to the number of the primary transistors.