Investigation of electromagnetic properties of two types passive retrodirective antenna arrays

In this paper, two types of passive, planar Van Atta antenna array are considered to study their performance in detail. For the edge-fed patch antenna array, the transmission lines are difficult to arrange and the whole size of the reflector becomes very large when the number of array element increases. For the aperture coupled patch antenna array, the feed lines and the radiating patch can be isolated from each other by the ground plane between the layers, which can minimize the spurious radiation of the feed and improve the radiation characteristics. The retrodirective angle range obtained by the aperture coupled antenna array is wider than that of edge-fed antenna array. For such case, the monostatic SCS is maintained about 160deg with 10 dB loss. To obtain more gain, a larger array can be composed by this 4times4 subarray, which can still keep the retrodirective performance with some affection in the bandwidth. More discussion and results will be presented at the conference.