An evolved S-band helical antenna with 1.8G bandwidth

Differential evolution (DE) is applied to optimize S-band helical antenna in this paper. The helical antenna spires on a paraboloid which is formed by revolving a parabola curve, not as usual as on the surface of a cylinder. And the spaces between two turns are changeable, not usually constant. In this way, the search space for the helical antenna is increased. This helical antenna design is then formulated into a constrained optimization problem (COP). The coefficients of the parabola curve and the spaces between turns are search variables. The design requirements are modeled into objective and constraints. An evolved antenna meets the requirements. It has a wider frequency band and higher gains than the referred one in this paper.

I. Introduction

Compared with the traditional manual design of antenna, evolutionary method can automatically search the design space and find new antennas which is more effective and practical. Antenna has begun to be designed by using evolutionary algorithms in about 1990, [1] [2]. Evolvable antenna research has been improved rapidly along with the development of evolutionary algorithms and electromagnetic simulators [1] evolved thinned antenna. [2]. automatically designed wire antenna. [3] evolved quadrifilar helical antenna [4] [5]. successfully evolved twisted helical antennas for NASA's satellite communication mission [6]. employed multiobjective genetic algorithm to design antennas Recently [7], used evolutionary algorithm driven by machine learning techniques to evolve antennas.