Improved Main-Beam Nulling Through Single Switchable Displaced Element for Small Scale Adaptive Array

This paper proposes a novel scheme to improve the signal-to-noise ratio (SNR) response of the main beam nulling for small-scale adaptive arrays. This method effectively promotes the main-beam nulling performance by introducing a displaced element at the end of an adaptive array. It is easy to implement with very low system cost. A detailed analysis of its working mechanism is provided, and the performance is verified with the simulation results. A switching scheme is introduced further to realize consistent performance for all nulling regions, which can attain similar main beam nulling performance as a larger-scale adaptive array. Combining with the active element pattern method, the performance of the proposed scheme involving mutual coupling is examined with a dipole array. It is consistent with the results acquired in isolated condition, which verifies its feasibility in practice.