RF Semiconductor Switch Voltage Control for Low-Loss Fast Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
MOSFETs formed on ordinary silicon substrates have large parasitic capacitance and cause significant electric-power loss for radio-frequency signals, making them inefficient for use in radio-frequency switches, and existing solutions like silicon-on-insulator substrates require larger layout areas and slower switching responses.
Innovation Solution
A semiconductor switch is designed with a switch section, a positive voltage generator, a driver, and a voltage controller on a single substrate, where the voltage controller connects and disconnects the output line from the power-supply line during specific periods to maintain optimal voltage levels, reducing power loss and improving switching speed without increasing layout area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a MOSFET is formed on an ordinary silicon substrate, then the device can be manufactured with standard processes, but the parasitic capacitance between the substrate and electrodes increases, causing electric-power loss
Solution Approach 1:
An insulator layer is introduced as an intermediary between the silicon substrate and the MOSFET electrodes. This insulator layer acts as a mediator that reduces the parasitic capacitance between the substrate and the source/drain electrodes, thereby reducing electric-power loss while allowing standard silicon substrate manufacturing processes to be used.
2Speed
If the layout area is increased to control potential fluctuations and achieve quicker switching responses, then the switching speed improves, but the device occupies more space
Solution Approach 1:
The insulator layer thickness parameter is optimized to achieve the desired switching response speed without increasing the layout area. By adjusting the thickness of the insulator layer, the parasitic capacitance is controlled, enabling faster switching responses while maintaining a compact device footprint.
Data Source
AI summary
A semiconductor switch includes: a switch section, provided on a substrate, switching connection states among a plurality of terminals; a positive voltage generator generating a positive potential higher than a supply potential supplied from a power-supply line; a driver, connected to an output line of the positive voltage generator, supplying a control signal to the switch section in response to a terminal switching signal; and a voltage controller, provided on the same substrate, controlling to connect the output line of the positive voltage generator to the power-supply line for a first period corresponding to a change in the connection states, and controlling to disconnect the output line from the power-supply line after the first period.