Advanced phase-locked-loop oscillators

This article presents a very sophisticated subclass of communication subsystems, namely oscillators, that use the phase-locked loop (PLL) technique. Some basic features and several application examples are presented that enable locking in the oscillator signal for each frequency offset. If the oscillator is used on its fundamental frequency, a high spectral purity is achieved without additional distortion. Furthermore, it can be increased by the filter function of the loop. An integrated 70 GHz synthesizer is introduced and discussed, and a microwave synthesizer module and its technical behavior is described. Several measured results supported by analytical considerations show the applicability and the high performance of the PLLs introduced.