Design concepts of instruments for vector parameter identification

The design concepts for phase-sensitive measuring instruments, which are based on two-phase synchronous detection and known as vector analyzers, are proposed. The main idea of the design is to use the advantages of both analog and digital signal processing methods by combining the synchronous detection and averaging procedures with the integrating analog-to-digital and functional digital-to-analog conversion principles. The reference channel of the vector analyzer is built up on the basis of the adaptive third-order phase-locked loop (PLL)