In this paper, a new method is proposed to reconstruct the complex aperture distribution of a phased array antenna with single RF channel. The method employs a non-uniform spatial sampling (NUSS) scheme of array elements. In this scheme, the elements are sequentially sampled with overlapping 'on' times so that two or more elements can be simultaneously on. Consequently, this type of sampling passes more average power to the single RF channel in contrast with the uniform sampling which permits only one element to be on while the others are off. To validate the proposed method, it is compared to the time sequence phase weighting (TSPW) technique which uses phase shifters to recover the distribution on the aperture array. It is found that the NUSS system has less computational complexity and consequently it is more suitable for real-time realization. The simulation results also show that it has superior performance over TSPW technique in terms of the error in amplitude and phase of recovered signals. Moreover, the effectiveness of our scheme is demonstrated by analyzing the maximum error in reconstructed aperture distribution with different noise levels and array sizes. Finally, to point out the radiation characteristics of NUSS technique, its array factor (AF) is illustrated and compared to the theoretical one. |
