Phase-Control Techniques for Sub-Sampling Phase-Locked Loops

Local oscillators with phase-control can be applied in a wide range of applications, from antenna phased arrays to synchronization. In this work, two techniques for introducing phase-control to a sub-sampling phase-locked loop (SSPLL) are presented. By means of a biasing voltage or a tuning current, it is possible to continuously control the output phase of the SSPLL within a 180-degree range. To evaluate both techniques, a proof-of-concept circuit was developed, simulated and measured, achieving good agreement with theory.