A monolithic six-port module for built-in-test applications

A fully monolithic six-port module is described. It includes a six-port junction, matched FET diode detectors, logarithmic amplifiers, and tunable Gunn-effect oscillators on a 3-mm × 3-mm GaAs die. On-chip temperature compensation of the detectors results in improved measurement reproducibility and increased dynamic range. In a reflectometer configuration, the monolithic six-port module (MSPM) demonstrates good agreement with National Institute of Standards and Technology (NIST) measurements on the same components. A built-in-test (BIT) demonstration of the MSPM allows the measurement of incident and reflected signals in an antenna feed while coupling less than 0.7% of the system power into the MSPM