Single pole-single-throw (spst) switch and its derivative single pole-double-throw (spdt) and single-pole-multiple-throw (spmt) switches

Abstract

A Single-Pole-Single-Throw (SPST) switch for RF application is disclosed that can include a semiconductor MOSFET transistor T, wherein its drain terminal can be connected to a resistor Rand capacitor C. It can have a source terminal connected to a resistor Rand capacitor C, a gate terminal connected to resistor R, a body connected by resistor Rto GND, and the body can be connected to the anode of a diode DE The Cathode of diode Dcan be connected to a power supply Vdd through a resistor R. The Cathode of diode Dcan also be connected to the cathode of another diode D. The anode of Dcan be connected to GND through resistor R. Capacitor Ccan be connected to an I/O port P, and capacitor Ccan be connected to an I/O port P. Inductor Lcan connect to ports Pand P, while inductor Lcan connect the source terminal and drain terminal of MOSPET T. This disclosure also provides a Single-Pole-Double-Throw (SPDT) switch and Single-Pole-Multiple-Throw (SPMT) switch based on the proposed SPST concept. The SPST disclosed can offer higher isolation and higher linearity to the transmit (TX) arm of the Radio-Frequency Front-End-Module (RF FEM), while maintaining relatively good performance in the receive (RX) arm of the RF FEM.