Synthesis of Highly Directive Endfire Arrays Using Modified Chebyshev Polynomials

Abstract

In this paper an additional parameter in the Chebyshev polynomial is introduced so as to design an endfire array by controlling two factors of the radiation characteristics- namely the Half Power Beam Width(HPBW) and the side lobe level(SLL) simultaneously. It has been shown that for a given SLL improved HPBW and First Null Beam Width (FNBW) can be achieved. Individual elements in the array are assumed to be isotropic. Simulations were carried out to find bounds on the choice of HPBW and SLL. Simulation results also shows that the directivity can be improved over the Dolph-Chebyshev array. Improvement in the roll off characteristics are also shown. Implementation of the array using the coefficients obtained by this synthesized procedure can result in a highly directive array.