Design, simulation, and fabrication of a MEMs switched superconducting microstrip hairpin filter

High performance high T_c superconductor based series micro electromechanical system (MEMs) switches have been utilized to switch between a bandpass hairpin filter, center frequency f₀ = 2.5 GHz, and BW of 250 MHz, and a through transmission line. This was accomplished with four switches actuated in pairs, one pair at a time. When the first pair is actuated, the through transmission line is capacitively connected between the input and output ports; accordingly, the system behaves as a throughline. When the second pair of switches is actuated, the bandpass filter is coupled to the input and output ports; thus a corresponding bandpass response is obtained. The design is implemented on a YBa₂Cu₃O₇ thin film deposited on a 15 mm × 15 mm LaAlO₃ substrate by pulsed laser deposition. BaTiO₃ deposited by RF magnetron sputtering is utilized as the insulation layer at the switching points of contact. The advantages and issues of this structure and its fabrication details are discussed along with simulations and experimental data.