Prediction of phase noise in 2.4GHz SAW oscillator with surface transverse wave resonator

Abstract

A surface transverse wave (STW) resonator based oscillator was developed in response to SONET OC-48 application. The residual noise measurement techniques are used to evaluate the noise contributions in feedback loop components, such as loop amplifier, STW resonator and electronic phase shifter, which can play important roles in determining the oscillator's output phase noise spectrum. The oscillator's phase noise floor is -170 dBc/Hz for carrier-offset frequency greater than 1 MHz. The oscillator's phase noise level of -67 dBc/Hz at 100 Hz carrier offset. Both low close-in phase noise and low white phase noise floor makes the oscillator meet low jitter requirement. The electronic frequency tuning range exceeds plusmn200 ppm. The oscillator provide 13.5 dBm of output power and consume 325 mW from +5 Volts power supply.