High spectral purity 26 GHz oscillator based on a SiO2 Whispering Gallery Mode Resonator

Patrice Salzenstein (1) , Rajae Barhaila (1) , Yannick Gruson (1) , Yann Kersalé (1) , Vincent Giordano (1)

1 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)

One of the key parameters to achieve high spectral purity microwave oscillators is the resonator Q-factor. Ultra high performances have been already demonstrated in X-band with Sapphire resonator. SiO2 monocrystal is another dielectric material to be considered. It presents low dielectric losses, is low coast and available in large size and high purity. We present the evaluation of a 26GHz-oscillator using a SiO2 monocrystal Whispering gallery mode resonator as frequency reference. The SiO2 resonator features a loaded Q-factor of 23000 leading to a phase noise Sphi (1kHz) = –73 dB.rad².Hz-1. This first prototype though not yet completely optimised demonstrates the potentiality of dielectric quartz resonator for the achievement of low phase noise microwave source.

Patrice Salzenstein, Rajae Barhaila, Yannick Gruson, Yann Kersalé, Vincent Giordano. High spectral purity 26 GHz oscillator based on a SiO2 Whispering Gallery Mode Resonator. 2002, pp.C036-C039. ⟨hal-00022879⟩