Parallel Testing of a Phase-Locked Loop Lock Time in Production

Methods to accurately measure a phase-locked loop lock time in a multisite production environment will be presented. These methods are also applicable for testing voltage-controlled oscillators or transceiver frequency settling times and frequency and phase errors after settling for multiple devices under test in parallel using onboard frequency mixers and radio frequency (RF) signal generators or using RF receivers of automated testers. Fast Fourier transform (FFT) techniques are used to measure the lock time in a case when output frequency error exists.