RF-MEMS Switched Varactor for High Power Applications

A new kind of MEMS switched varactor has been developed to handle high power RF signals, (P>1W), at S and X-band. The design principle is presented, as well as measurements results featuring an analysis of the reliability tests. The fabricated varactors have shown a capacitance ratio of 7-8 at 5 GHz and good performances reproducibility while undergoing 1 billion cycle tests under an input RF power of 1W @ 10GHz, and 250 million cycle tests under 5W @ 3GHz, both in hot switching conditions, without visible degradation

I. Introduction

Recently developed antenna and radar communication systems exhibit an increasing demand for high Q, tunable capacitors to perform varactor operations up to millimeterwave frequencies. MEMS varactors potentially fulfill these requirements due to intrinsic properties of MEMS components. A large range of electronic devices can benefit from MEMS varactors, like antenna beam forming networks and reconfigurable RF filters [1]–[3]. Co-integration with gallium nitride devices is also very promising due to power and bias voltage compatibility.