Designing Planar Frequency Diverse Arrays in Space-Frequency Domain

Abstract

Antenna arrays benefit from spatial diversity, which allows controlling the pattern specifications in space. Adding frequency diversity to the arrays initiates opportunity to control the beams in the Space-Time domain. Frequency Diverse Array (FDA) has a Range-Angle dependent pattern; therefore, the array's spatial and time behavior should be designed simultaneously for optimum performance. Due to the lack of simple array factor formulations for non-regular configurations, array geometry design has not been the primary concern in many current studies. Due to coherency between frequency and spatial distribution in FDAs, the spatial and time behavior of the pattern is correlated. Frequency diversity of the FDA leads to time-variant beam in steering and auto-scanning beam in CW applications. The present study in addition of SLL discusses two important scanning array parameters; the pattern periodicity and stability in each scan round. In this study using some symmetry rules, a straightforward formulation for the array factor is obtained and used to achieve a stable and periodic scanning beam, suggesting a novel joint space-frequency allocation scheme for the FDA. The approach allows the location and frequency of elements to be designed in the frequency-space plane that minimizes the error function, which is defined based on the time and spatial behavior of the array. Using these concepts, two arrays are designed, and their results are compared with other planar configurations. This study paves the way for a new approach to design FDAs.