Microwave resonant transmission in a superconducting fabry-perot bilayer

Microwave resonant transmission properties in a superconducting Fabry-Perot bilayer made of a high-temperature superconductor (YBa ₂Cu ₃O _7-x ) and a nearly ferroelectric superconductor (n-SrTiO ₃) are theoretically investigated. The effect of high-temperature superconducting layer on the unusual resonant transmittance existing in a nearly ferroelectric superconductor is investigated. It is shown that a frequency-agile two-layer coating can be obtained with the addition of the high-temperature superconducting coating. Resonant frequencies can be shifted by varying the thickness of this coating. In addition, the ultra-narrow filtering feature makes such a bilayer resonator useful in the superconducting microwave electronics, such as a frequency sampler or spectrum analyzer in the signal processing.