Role of perturbations for dual mode superconducting microstrip resonators fabricated by laser ablation

The comparison of frequency response characteristics between various types of superconducting dual mode resonators has been performed. Epitaxial superconducting YBa/sub 2/Cu/sub 3/O/sub 7-x/ (YBCO) thin films have been have been grown on MgO substrates by laser ablation. Perturbed disk and ring types of superconducting dual mode resonators were patterned by photolithography and a wet-etch process. Unlike the unperturbed case, dual mode resonators have different resonant properties for the perturbed case depending on the position of the perturbation. We observed the same resonant peak splitting properties at the fundamental resonances of the perturbed dual mode disk and ring resonators. Peak properties caused by perturbation in the dual mode resonators could be used in implementing a two pole bandpass filter by itself.<>