RECEIVER HAVING A PHASE-LOCKED LOOP

摘要

In a receiver, a phase-locked loop (PLL) is provided for synchronizing its oscillator (OSC) with a carrier (CA). A calibration circuit (CAL) calibrates the phase-locked loop's oscillator (OSC) as follows. It measures (FMC) the frequency difference (dF) between a nominal frequency (Fnom) of the carrier (CA) and a frequency (Fosc) of the phase-locked loop's oscillator (OSC). Furthermore, it adjusts (FCA) the frequency (Fosc) of the phase-locked loop's oscillator (OSC) in accordance with the measured frequency difference (dF). As a result, the phase-locked loop's oscillator (OSC) will be substantially tuned to the nominal frequency (Fnom) of the carrier (CA). The actual frequency of the carrier (CA) may differ from the nominal frequency (Fnom). In general, such a difference will be sufficiently small for the phase-locked loop (PLL) to capture the carrier (CA).