A New Approach to Frequency Synthesis

A new approach to frequency synthesis permits the achievement of excellent spectral purity, high agility, very fine resolution, low power consumption and low cost. The principle of the proposed Phase Digital Synthesizer (PDS) is that the control signal of the PLL is formed by a multi frequency-phase comparator with phase splitting of the reference and VCO signals into a large group of signals which are compared in the partial detectors. The outputs of these partial detectors are then summed to develop the VCO control voltage. The main advantage of the method is that there is no division ratio in the loop and thus there is no multiplication of noise and spurs normalized to the phase comparator. The synthesizer of PDS type can be used instead of complicated multi-loop systems which are too expensive, bulky and with high power consumption.