A 2 GHz surface transverse wave oscillator with low phase noise

Abstract

A hybrid oscillator at 1.9805 GHz using acoustic surface transverse wave (STW) delay lines operating at the third harmonic as the frequency controlling element is discussed. The STW delay lines were fabricated on 37.5 degrees -rotated Y-cut quartz substrates with a photolithographic technique. A very thin metallization (25 nm) was used to obtain low insertion loss. A split isolated electrode design was used for the transducers. The Q-value and the untuned insertion loss of the STW filter were 3400 and 21 dB, respectively. The phase noise and temperature stability of the oscillator were characterized. At a power output of 6.5 dBm a single-sideband phase noise-to-carrier ratio of -100 dBc/Hz at 1 kHz was attained.