VCO, PLLs, Frequency Synthesizers & Demodulators

Voltage-controlled oscillators (VCOs) generate a periodic waveform of a frequency controlled by an input voltage. Phase-locked Loops (PLLs) generate an output signal with a phase related to the phase of a reference signal. Frequency synthesizers generate output signals in a range of frequencies from a fixed timebase or oscillator. Demodulators use different methods to recover a signal from a modulated carrier wave.