Performance enhancement of nulling antennas by utilizing the concept of multiplicative array

In this paper, we propose a beam forming architecture for improving the power-inversion algorithm that is most commonly used in nulling antenna systems. To prevent the possible degradation of the original gain of a nulling antenna in the circumstance when there exists strong interference, we multiplex the received signals from the physical radiation elements in digital domain with a power-inversion array (PIA) and a primitive array (PA), and then form the desired radiation pattern by multiplying the outputs from PIA and PA, to obtain expected narrow nulls in the directions of the interference and in the meantime roughly maintain the original gain and the beam shape of the main lobe. Simulation fits well with the analysis, showing the effectiveness of the proposed approach.