Design of Circular Log-Periodic Arrays using Electromagnetic Simulations

This paper considers the design of circular arrays of log-periodic (LP) antennas by taking advantage of a powerful electromagnetic simulation environment. The antennas were modeled using perfectly conducting sheets and applied the electric-field integral equation (EFIE) to solve the radiation problem in the frequency domain. The simultaneous discretization of the geometry and the integral equation led to a matrix equation, which was solved by an iterative method employing the multi-level fast multipole algorithm (MLFMA). The excitations of the antennas in the circular arrays were optimized by the genetic algorithms to add a beam-steering ability to the arrays. Results of two different types of array configurations were presented to demonstrate their broadband and beam-steering properties