Oscillator temperature compensating circuit using stored and calculated values

Abstract From the Canadian patent

A voltage-controlled oscillator includes a compensating signal value calculator which calculates the value of a function representing the portion of the oscillator temperature-frequency transfer curve corresponding to the ambient temperature. A signal corresponding to the calculated value is then applied to the voltage-controlled oscillator as the control voltage. Basically, an oscillator temperaturefrequency transfer curve is partitioned into n segments. For each segment an offset value, xn, equal to the difference between the frequency at the start of the segment and the desired frequency, is stored in a look-up table. When a compensating signal value is required, the compensating signal …