A method for measuring time delay behavior of antennas

The group delay behavior of antennas is of high importance for high accuracy localization and navigation systems. Next to the design of these antennas a measurement method is needed to determine this parameter. Using a vector network analyzer is a classical means to get these results. Nevertheless this method is very time consuming with respect to creation of a time delay variation pattern for example. The method described in this paper is based on the measurement of the time of arrival of a broad-band signal in a synchronized setup. This setup consists of a signal generator which transmits a bursted sequence of the measurement waveform. A synchronized tuner and data acquisition system determine the time of arrival of the signal. Detailed measurements of different kind of antennas have been performed in the 2.45 GHz ISM band and will be presented.