A dual six-port automatic network analyzer incorporating a biphase-bimodulation element

Current state-of-the-art dual six-port automatic network analyzers (ANAs) are dependent upon mechanical phase shifters and attenuators. Slow measurement and calibration are among the factors that have prevented six-port ANAs from more general use outside standards and research laboratories. Biphase bimodulation, a technique which removes the requirements for mechanical phase shifters or attenuators, is introduced. The technique provides improved sensitivity and elimination of drift as a consequence of AC modulation. A significant increase in measurement speed is achieved, allowing quasi-real-time evaluation of scattering parameters. An experimental prototype dual six-port ANA is described, and results obtained using the technique are given.>