PHASE/FREQUENCY MODULATOR

摘要

A modulator circuit for modulating a radio frequency (RF) signal with two signals which are in quadrature with one another includes a phase-locked loop (PLL) with a quadrature modulator within its output signal feedback path. The PLL generates an RF carrier signal which is phase-locked to a fixed-frequency reference signal and is modulated by modulating the VCO output feedback signal fed back to the phase detector of the PLL.