Highly Efficient MOSHFET Based X-band Transmitter-Switch Module

The output power and power added efficiency are the key performance parameters of modern transmitter/receiver (T/R) modules. The optimization of these parameters depends mostly on the RF characteristics of the active elements used in the T/R module output stages. GaAs FETs and HFETs that are currently used do not allow for high drain bias and large input signal swings. Power combining elements result in additional RF losses. Similar limitations are present for the T/R RF switches based on p-i-n diodes or GaAs transistors. GaN based HFETs allow for much higher single element output powers. However, the power added efficiency optimization is limited by severe increase in the gate leakage currents both under the reverse and forward biases. We propose to use our proprietary and patented III-Nitride based Metal-Oxide-Semiconductor Heterostructure Field Effect Transistor (MOSHFET) technology and develop high power added efficiency output stages integrated with RF switches. GaN has been under intense investigation in the last ten years due to its high breakdown field and high temperature operation. GaN transistors operating up to 600C is available in reports from various researchers.