Linear connected arrays [coupled dipole arrays

Abstract

The concept of connected (or coupled) dipoles in a linear array, which improves wideband performance, is examined. A long wire with multiple feeds is the model, using rigorous moment method analysis. The edge waves of the current appear not to be attenuated; around half-wave dipole length, the current peaks are one wavelength apart, with deep nulls. For dipole lengths around quarter-wave the current peaks and dips are modest. This trend continues to shorter dipoles; for lengths of 0.1 wavelength or less, the current is nearly constant along the array. This approximates the current sheet of Wheeler; the impedance mismatch is much less severe than for an array of unconnected dipoles of the same dimensions.