Mitigation of multiple reflections in antenna pattern retrieval method

In this paper, a recently proposed method for antenna radiation pattern retrieval is studied. The method is based on measurements of reflection coefficients when a reflective load is moved in front of the antenna under test. It has been proposed to be used for on-wafer antenna measurements in the probe station environment. However, the method may be subject to multiple reflections and, therefore, time gating is studied in order to mitigate the effect of reflections. This paper evaluates how time gating affects the determination of the reflection coefficients. The time gating is demonstrated by simulations of a pyramidal horn antenna at 30 GHz. Practical implementation and experimental results of time gating at millimeter wavelengths are presented using a probe-fed 4 by 4 patch antenna array.