Design and fabrication of two switch superconducting microstrip hairpin filters using series MEMS switches

A superconductor circuit based on series Micro-Electro-Mechanical (MEM) switches is utilized to switch between two bandpass hairpin filters with 200 MHz bandwidth and nominal center frequencies of 2.1 GHz and 2.6 GHz. This is accomplished using 4 switches actuated in pairs, one pair at a time. When one pair is actuated the first bandpass filter is coupled to the input and output ports. When the other pair is actuated the second bandpass filter is coupled to the input and output ports, thus corresponding output responses are obtained. The device is made of YBa₂Cu₃O₇ thin film deposited on a 20 mm × 20 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. Fabrication details are discussed along with simulation data and test results.