Analytical Description and Design of Printed Dipole Arrays for Wideband Wide-Scan Applications

Wideband arrays of printed dipoles with interelement loads are investigated. A closed-form expression for the active input impedance of the array element is derived with a spectral domain approach. The procedure is based on an extension of the Greens function formulation for arrays of connected dipoles to the case of dipoles coupled via loads. The accuracy of the formulation is investigated with the aid of parametric analyses. The model can be used in the preliminary design of wideband printed dipoles for the dimensioning of the radiating elements. The procedure remains accurate also for arrays of dipoles that are not tightly coupled, for which and the current along the element assumes a resonant-like sinusoidal distribution.