ISSN:
1572-9605
Keywords:
Surface impedance
;
microwave passive devices
;
YBCO thin films
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Physics
Notes:
Abstract High-T c thin films continue to be of interest for passive device applications at microwave frequencies, but nonlinear effects may limit the performance. To understand these effects we have measured the nonlinear surface impedanceZ s in a number of YBa2Cu3O7−x thin films as a function of frequency from 1 to 18 GHz, rf surface magnetic fieldH rf to 1500 Oe, and temperature from 4 K toT c . The results at lowH rf are shown to agree quantitatively with a modified coupled-grain model and at highH rf with hysteresis-loss calculations using the Bean critical-state model applied to a thin strip. The loss mechanisms are extrinsic properties resulting from defects in the films. We also report preliminary measurements of the nonlinear impedance of Josephson junctions, and the results are related to the models of nonlinearZ S . The implications of nonlinearZ S for devices are discussed using the example of a five-pole bandpass filter.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00727495
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