Newnes Radio and RF Engineering Pocket Book, 3rd Edition

6 Oscillators

6.1 Oscillator requirements

Oscillators generate the frequencies used in radio and electronic

equipment. The performance of those which determine the operating

frequencies of radio systems is tremendously important. Most

oscillators must:

• Generate a precise frequency of high purity.

• Be highly stable, i.e. produce an output constant in frequency and

level despite changes in temperature, supply voltage and load.

• Be tunable in frequency.

• Produce minimum noise and microphony (fluctuations in frequency

with vibration).

These requirements conflict. A readily tunable oscillator cannot be

precise and highly stable, and compromises must be made; ...