Equivalent Circuit Model of Unbalanced Fed Tightly Coupled Dipole Array For Analyzing Even and Odd Modes

In this paper, an equivalent circuit model of an unbalanced fed tightly coupled dipole array (TCDA) is proposed. Unbalanced excitation can be decomposed by even and odd modes excitation. Antenna input impedances of each mode are expressed and their relation to that of unbalanced mode is determined. Herein, determining an even mode circuit is focused on to construct an equivalent circuit of unbalanced mode. Additionally, the unbalanced fed TCDA with shorting vias is proposed, and its bandwidth is compared with that of the balanced fed TCDA.