Broadband composite dipole antenna arrays for optical wave mixing

Abstract

A broadband composite dipole array (CDA) includes an array of macro dipoles on a non-conducting substrate adapted to receive radiation at two frequencies. Each macro dipole is an array of micro dipoles adapted to receive radiation at substantially the mean of the two frequencies. The micro-dipoles are coupled to each other by a parallel resonant circuit including a nonlinear element, wherein the minimum impedance of the circuit is a substantially short circuit at the difference frequency f−f, and the circuit has a substantially open circuit impedance in the range of frequencies from fto f. The micro dipoles resonate efficiently at both frequencies fand fwith low-loss. The nonlinear element in the resonant circuit generates a signal at the difference frequency which is the resonant frequency of the macro dipole antenna. A composite of macro dipole antennas couple electromagnetically via a cluster of micro-dipole elements to broaden the bandwidth over a range of frequencies from fto fat which the macro dipole antenna resonates.