The Measurement of Complex Antenna Transfer Functions for Ultra-Wideband Antennas in a Compact Range [Measurements Corner]

Ultra-wideband (UWB) communications technology increasingly plays an important role in modern communications systems. The complex antenna transfer function (CATF) of a UWB antenna provides valuable information that can be used for better UWB channel and communication system designs. Currently, only the two-antenna and three-antenna measurement techniques are used to measure the transfer functions and impulse responses of UWB antennas. In this paper, a modified version of the gain-transfer method is presented to enable the characterization of UWB antennas using a compact antenna test range facility (CATR). A double-ridged guide horn (DRGH) antenna was used as a UWB transfer-standard, and the complex antenna transfer function of the transfer-standard was determined a priori using full-wave simulations. The gain-transfer method to measure the complex antenna transfer function of UWB antennas in a compact antenna test range was illustrated with two test cases. In the first test case, the measured complex antenna transfer function of an ETS-Lindgren double-ridged guide horn antenna was verified with numerical data from a FEKO model of the antenna. The second case compared the complex antenna transfer function of a UWB circular disc monopole antenna measured in a compact antenna test range to measured data using two identical antennas in a two-antenna measurement setup.