Antenna Radiation Pattern Measurement in a Reverberating Enclosure Using the Time-Gating Technique

Abstract : This letter describes an original approach to measure the radiation pattern of an antenna within reverberating enclosures. In such kind of enclosures creating a multipath environment, the key point is to distinguish the line-of-sight (LOS) path between the antenna under test and the measuring antenna from all the other indirect paths. This is made possible by taking advantage of the time-gating technique considering that the LOS path arrives the first on the measuring antenna. With respect to the existing methods proposed recently, the method leads to significantly simplify the measurement setup and shorten the measurement time (similar to the one obtained in anechoic chamber) as no stirring process or any movement of the antenna under test (apart of course from the rotation on itself) is required. Moreover, the accuracy of this method is presumably better in reason of the ability of the time-gating technique to discard the influence of the indirect paths. The proposed technique tested for the first time within reverberating enclosures is experimentally validated on a broadband horn antenna from 1.5 to 12 GHz. The main parameters influencing the result (the measurement bandwidth, the frequency resolution, the time-gating window width and the effect of loading the enclosure) are discussed.