Simple Broadband Measurements of Balanced Loads Using a Network Analyzer

This paper presents a simple broadband network analyzer technique for measuring balanced loads, such as antennas, without a balun. The technique uses the normal two-port calibration of the network analyzer, which is extended by the addition of two short lengths of cable. From the measured data, a circuit model of the antenna impedances can be found, and both the balanced and unbalanced impedances are readily extracted. Measured and computed data are presented and compared.