S R F    2 0 0 3

SRF2003 Show Abstract

Title Selective mode dumping and improvement of the quality factor of a microstrip resonator
Type Poster coupler / tuner / controls
Abstract The highest achievable quality factor (Q) values of a microwave resonator may be restricted by radiation losses caused by intermode coupling. It may be difficult to improve Q by dumping the intermode coupling while a complete mode spectrum is unknown. This is a true for semi-open microstrip-like resonators. Previously it has been found that negligible geometry fluctuations of the microstrip resonators result in strong and unpredictable changes of Q from less than 10E3 to higher than 10E5. Here we have studied the influence of the dispersion properties on the loss characteristics of the superconducting microstrip-like resonator. Transmittance spectra of the half-wave resonator have been measured in 10 GHz frequencies range. The electromagnetic field was intentionally disturbed outside in the region of transmission lines to dump modes selectively. Series of Q measurements using short-circuited stubs on input and output microstrip lines were performed in order to find interaction of the main half-wave resonance mode with other modes. It is found that spectrum of resonances includes parasitic modes, the energy of which is concentrated mainly in the region of connecting microstrip lines. Interaction of the main mode with parasitic ones significantly reduces the highest Q value of the main operating mode. It is also demonstrated that dielectric resonance in the dielectric substrates of resonator can be excited.

List of authors...

Principle author first.

Last (Family) Name First Name (Initials only) Affiliation or Organization (abbreviations if possible)
Karuzskii A. L. LPI
Lykov A. N. LPI
Murzin V. N. LPI
Volchkov N. A. LPI

SRF 2003Webmaster