A Short-Range Range-Angle Dependent Beampattern Synthesis by Frequency Diverse Array

In this paper, we propose a new technique to generate a range-angle dependent transmit beampattern by introducing a nonlinear frequency modulation scheme based on arctangent function in the frequency diverse array (FDA) system. The propagation process of the transmitted signals is usually neglected in most of the existing range-angle dependent transmit beampattern synthesis schemes. More specifically, the time variable is considered to be a constant value or defined from 0 to T, where Tis the pulse duration for pulsed FDA. As a result, such schemes cease to focus the signal power at a desired position for a period of time when this practical constraint is taken into account. The proposed methodology incorporates the propagation process of the transmitted signal and simultaneously focuses the signal power at a desired position and lasting for a period of time. We investigate the consequences of this constraint briefly and also explain the corrected model. Numerical simulations are implemented to validate the theoretical analysis of the proposed methodology.