Abstract: The phase range of a phase detector is extended while maintaining its modulation bandwidth and linearity. The range is widened by dividing down the frequencies to be compared. Clocked delay lines create sequentially delayed multiple-phase signals which are applied to a plurality of component phase detectors. The outputs of each of the component phase detectors are summed to restore the frequency of the original clock signals to the output components. This technique is especially useful in high-speed phase detectors.