An efficient six-port procedure for power meter calibration

A method for the efficient calibration of a single six-port network used to measure both the effective efficiency and the calibration factor of a power meter is presented. An automated 2-18-GHz implementation and the validation of the method are described. The junction is based on a design using four quadrature hybrids, with the forward and reflected waves sampled using 3-dB and 10-dB couplers, respectively. Because there is no need to tune the test port to a match at each frequency, the presence of a maladjusted lossless tuner between the test port and the power meter should not affect the value obtained for the effective efficiency, although the calibration factor will vary. This concept has been used to test the system by measuring the effective efficiency and calibration factor of a combined tuner and power meter at one frequency. The results demonstrate that the measured effective efficiency is constant to within 0.1% for reflection coefficients up to 0.2.<>