Electromagnetic and mechanical behaviours of whispering gallery mode resonators [for space application]

Frequency and time metrology, modern telecommunication systems and space applications require X-band signal sources with increasing phase noise performances. In this field, the sapphire whispering gallery mode resonator (WGMR) seems to be very attractive. Exceptional phase noise performances have been recently reported for X-band sources based on such type of resonator. Although the WGMR structure seems relatively simple, the design of an operational resonator brings out a number of technological problems, especially for space applications where in-board systems are submitted to severe environmental stresses. This paper resumes our investigations on the design of an X-band WGMR for space applications. We present the measurement results of sapphire permittivity, electromagnetic resonance frequency determination and studies of vibrational behaviour of WGMR