Whispering gallery resonators with programmed temperature coefficient of frequency

This paper describes a new design method of "whispering gallery" resonators (WGR) leading to desirable temperature coefficient of frequency (TCF). The method is based on our preceding results and implicates special shaping of a disk WGR made from uniform anisotropic dielectric. The particular solution looks like a double-sided wedge-shaped groove made on disk butt-ends in the vicinity of a radial electric field maximum. By choosing the groove width and depth, WGR can be tuned at a desirable TCF including frequency-temperature compensation. The described method is general and can be applied to WGRs made from any dielectric crystal having suitable properties. The design of experimental samples was achieved by implementing finite element software. An experimental study also has been performed.