Numerical analysis of a dual-spiral printed antenna

A dual-spiral antenna has the advantage that the two spiral elements are simultaneously fed from one source. The radiation characteristics of this antenna have been calculated using the current distribution. The calculations show that the dual spiral can radiate a circularly polarised wave. So far, the radiation efficiency of this antenna has not been described. Therefore, the authors reveal the radiation efficiency, together with the other radiation characteristics. The effects of the dielectric substrate thickness and dielectric constant (relative permittivity) on the radiation efficiency are presented and discussed