Frequency and low-temperature characteristics of high-Q dielectric resonators

Accurate calculations of unloaded Q for the TE/sub 01 delta /, TM/sub 01 delta /, EH/sub 11 delta /, and HE/sub 11 delta / modes in a dielectric rod resonator placed in a conductor cavity are described. The calculated results are verified experimentally. The mode designation is investigated from the viewpoint of field distribution. In particular, for high-Q TE/sub 01 delta /-mode dielectric resonators, the frequency and temperature characteristics are discussed. A typical result measured at 4 GHz shows unloaded Q values of 45000 at 20 degrees C and 140000 at -180 degrees C with a temperature coefficient of frequency of 1.5 p.p.m./ degrees C.<
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