Practical Considerations in Frequency Diverse Array Radar Signal Processing

Abstract

The frequency diverse array (FDA) has been shown to produce a range and angle dependent beampattern, unlike a conventional phased array which yields only a direction dependent pattern. The FDA generates a range-selective projection on to the far-field region that migrates spatially along the extent of the functional range. A recent FDA architecture known as equivalent transmit beamforming has been demonstrated to exhibit a time-independent behavior that can potentially simplify the receiver signal processing. This thesis studies lapses in practical considerations of equivalent transmit beamforming system operations. The influence of target motion on equivalent transmit beamforming is elaborated upon, and a metric is constructed to quantify the adverse consequences of a non-stationary target on system detection capabilities. The equivalent transmit beamforming scheme is then translated onto 2-dimensional arrays that have more flexibility in control across dimensions (range, azimuth, elevation). The unique array factors of the planar configurations are formulated from which the radiation characteristics are gauged in order to assess the relative performance of each configuration. Finally, the effect of unknown mutual coupling in both transmit and receive mode is considered. An algorithm is proposed which performs online joint estimation of the mutual coupling coefficients and the target parameters, along with a mutual coupling compensation method. Detailed signal model formulations and simulation results are included to confirm the results of this work.