A low-cost comb generator for the characterization of test sites

A low-cost comb generator based on a PLL scheme is presented in the paper. It can be used to characterize test sites where a wide band analysis (in the range 600MHz - 12GHz) with a compact and portable device may quickly provide the required results. The good spectral purity, the tunable generated frequency and the long-term stability characteristics of the proposed generator make it useful also for additional interesting pre-compliance tests. Detailed description of critical design issues both establishes useful guidelines for EMC designers, and provides a better understanding of low-noise PLL circuits.