RF power dependence of YBCO thick films

The dependence of Q on incident power has been measured for an all-thick-film YBa/sub 2/Cu/sub 3/O/sub x/ cavity resonating in the TE/sub 011/ mode at 5.66 GHz and 77 K. The high unloaded Q of 715000 measured at low incident power levels decreases as the power level is increased, but remains over 200000 with 1.4 W incident on the cavity, which corresponds to 0.7 W dissipated in the cavity. The data have been used to calculate the RF power dependence of the R/sub s/ of thick-film YBa/sub 2/Cu/sub 3/O/sub x/, which is shown to be approximately linear for RF fields between 0 and 0.5 mT.<
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