High power RF switch MMICs development in GaN-on-Si HFET technology

Abstract

The development of a high power RF SP4T MMIC switch using AlGaN/GaN HFETs on Si substrate is reported for applications up to 2 GHz. The offstate capacitance (Coff) of a single-gate GaN based HFET is 250 fF and the on-state resistance (Ron) is 4.1 at a gate length of 0.7 m and a width of 1 mm. The MMIC SP4T switch with a size of 1.2x1.6 mm 2 is implemented for system applications of three transmit paths and a receiver, of which each was configured with a series-shunt self-biased configuration. The switch has achieved an insertion loss of -0.95 dB with power handling of P(-0.1dB)=45 dBm at 1 GHz at the transmitter paths and an optimized isolation of better than 28 dB at the receiver path of up to 2.5 GHz. In addition, a high voltage switch driver using the GaN power HFET technology was designed with an input control voltage of 0/2.3 V to provide an output voltage of 0/28 V. This development provides a baseline design for our first generation MMIC switches in GaN technology.Index Terms -GaN HFET, MMIC switches, high power switches, SP4T.

A Loosely Coupled Planar Wireless Power Transfer System Supporting Multiple Receivers

“…It is possible to find switches which operate at high frequencies but the power handling starts to drop with increasing frequency [23] unless expensive novel materials are used as shown in [24]. Most importantly, it is difficult to control the switch with voltages lower than the voltage being switched using a simple transmission gate topology or switch transistors.…”