Temperature compensation of SAW oscillators

A method for the compensation of surface acoustic wave (SAW) oscillators is described. This work is a development of a technique first used for compensation of AT-cut bulk crystal oscillators. The benefits that result for SAW oscillators are high compensation performance, low power consumption, low complexity and relatively low cost. Compensation is achieved by the use of a custom bipolar integrated circuit which generates a power series representation of the control voltage of a voltage-controlled SAW oscillators. A prototype oscillator has been built at 600 MHz and shows a compensated performance of +or-4 p.p.m. over a 120 degrees C operating temperature range. The potential to improve the performance to +or-2 p.p.m. exists.<>