An Automatic Homodyne Network Analyser with Phase Shift Keying and Baseband Data Sampling

A homodyne network analyser is presented which makes use of a chain of up to three digital phase shifters with unknown but reproduciblephase shift/insertion loss changes which allows a direct computation of the transfer function of a device under test (DUT). The principle can be extended to single sideband receivers with enhanced image sideband suppression. The performance of the microcomputer controlled network analyser system is demonstrated in the X-band and Ka-band range. Phase errors are typically below ± 1° for X-band frequencies and ± 1.5° in the Ka-band range.