Effects of the finite HTS film thickness on the resonant frequency of the axially symmetric TE01 delta mode of a parallel plate dielectric resonator

An axially symmetric TE01 delta mode of a parallel plate dielectric resonat or is studied for investigating effects of the film thickness (t) of high-t emperature superconductor (HTS) films on the mode resonant frequency (f(0)) A sapphire-loaded cylindrical cavity resonator with YBa2Cu3O7-delta (YBCO) endplates and mode f(0) of about 19 GHs has been prepared and its unloaded Q (Q(0)) and f(0) are investigated at temperatures below the critical temp erature of YBCO. From theoretical analysis, it appears that f(0) changes by less than 0.4% for different t's when the ratio of t to the London penetra tion depth (lambda) is more than 10(-2) Meanwhile, from experiments, signif icant dependence of f(0) on the gap distance (s) between the sapphire rod a nd the top endplate is observed with f(0) changing by about 1 GHz (similar to 5 %) from 19.578 GHz to 18.848 GHz as a increases from 0 to 1 mm at 77 K . The experimental values of f(0) are observed to agree well to the calcula ted f(0). Applicability for tunable high-Q resonators is described.