Efficient, Semi-Analytical Characterization of a Double -Loop Antenna Array

Circular, double-loop arrays are analyzed via a semi- analytical technique, based on a Moment Method formulation. A Pocklington-type integral equation for the current is cast and discretized through step pulse basis functions. The resulting linear system has a block-circulant form, and is therefore solved analytically, circumventing any possible complications related to numerical inversion of large, ill-conditioned matrices. Using a delta gap source as an excitation, the current and input admittance computation becomes an easy task with minimum mathematical cost. The algorithm utilizes mainly elementary functions and yields results in terms of a rapidly convergent series, applicable to extremely large loops. Data for such loops are presented for the first time in literature.