GENERATION OF DIGITAL CLOCK FOR SYSTEM HAVING RF CIRCUITRY

摘要

Circuitry for any of a transceiver, a transmitter, and a receiver, has RF circuitry (70), digital circuitry (30, 250, 260), a carrier signal generator (80) to provide a carrier signal to the RF circuitry and a clock generator (90) for generating a digital clock for clocking at least some of the digital circuitry. The RF circuitry is susceptible to interference from harmonics of the clocking, and the clock generator derives a frequency of the digital clock based on a frequency divided down from a frequency of the carrier signal so that the interference to the RF circuitry occurs at frequencies which are harmonics of the carrier signal. Since any interference from harmonics of the digital clock are at frequencies which are harmonics of the carrier, they can be compensated more easily, or can be arranged to have frequencies far enough away from useful parts of the RF signals to be filtered out more easily.