Silicon MEMS Tunable Superconducting Microwave Circuits

M.J. PREST, Y. WANG, F. HUANG and M.J. LANCASTER

University of Birmingham, Electrical, Electronic and Computer Engineering, Birmingham, B15 2TT, UK.

Abstract. Tuning of a superconducting microwave resonator, operating at 77 K, is demonstrated using a silicon micro-machined comb-drive actuator. Thermal expansion coefficient differences between the silicon actuator and the MgO substrate are accommodated by the use of compliant springs and a stress-buffering rigid frame. A tuning range of about 3 % is demonstrated for a microwave resonator with a frequency close to 6 GHz. Measurements of Young’s modulus show that the value at 77 K is within 1.5 % of the room temperature value.