Low Voltage Saw Oscillator

Modern RF transceivers require a local oscillator with minimal phase noise to meet the stringent requirements of today's wireless systems. Furthermore, emerging wireless applications require that the power consumption of the whole system be minimized, especially in mobile units. In addition, there is a trend towards using low supply voltages in portable communication circuits. This paper describes the design of an surface acoustic wave (SAW) oscillator that is based on a Pierce topology, operating at 976 MHz. The active components of the circuit are implemented in CMOSP $0.18-\mu {\rm m}$ technology and operate with 1V power supply. The oscillator has a power consumption of 9.4 mW at 976 MHz with a phase noise of −156 dBc/Hz at an offset of 600 kHz. An output buffer stage is used, with a supply current of less than 2.5 ms. A figure of merit for the circuit is computed and shown to be an improvement over previously published works.