Performance of temperature-stable RF MEMS switched capacitors under high RF power conditions

This paper presents a temperature-stable RF MEMS shunt capacitive switch which employs a circular beam geometry. The circular switch reduces the effect of stress changes versus ambient temperature and results in a average pull-in voltage slope of only -55.8 mV/°C from -5-125°C. This novel device is simulated and tested under continuous RF power at 10 GHz. Results show that the non-uniform temperature distribution of the MEMS bridge, due to the RF power absorbtion, leads to a decreasing up-state capacitance and increasing spring constant. This combination results in a switch that does not suffer from self-actuation up to power levels of 5.2 W, limited by the test setup. The RF power handling measurements are in good agreement with simulations.