Equivalent circuit model for arrays of square loops

Arrays of square loops are of interest as frequency-selective surfaces for dichroic reflector antennas. A description is provided of a lumped-element equivalent circuit model for the square-loop array, taking into account a comparison of the transmission characteristics predicted by the model with those obtained experimentally. The modeling technique is based on equations given by Marcuvitz (1951) for the impedance of periodic arrays of thin continuous conducting strips. The model can be used where the element geometry may be recognized as consisting of inductive and capacitive components. In the proposed model, the array is represented by a single series LC circuit shunted across a transmission line.