Near field focusing properties of an integrated retrodirective antenna

The near field behaviour of two different types of retrodirective antenna arrays are presented. For each type it is shown that retrodirective properties can be preserved well into the antenna array near field. To our knowledge for the first time it is shown that distortions arising in the radiation pattern of each array type primarily occurs due to the effect of the individual radiation pattern characteristics of the elements comprising the array and the different path loss from the excitation source to the MRCS (monostatic radar cross section measurement) receive element. In this paper theoretical results are compared with measured data. The results obtained have importance for wireless communication systems where mobility is important.