Miniaturized quadrature coupler using low-cost instant inkjet printing technology

Abstract

This article presents the design and implementation of a Miniaturized 3 dB hybrid coupler with low-cost instant inkjet printing technology. The coupler has a promising potential advantage in applications in antenna beam forming network and feeding networks for phased antenna array. Explicit design equations were derived and used in the design of the coupler. To validate the design procedure, a prototype of the 3-dB coupler was implemented using the low-cost instant inkjet silver-nano printing technology. The responses of the hybrid show that the return loss and isolation are both below −20 dB at the designed frequency. The size reduction of this coupler is 73.7%. However, there is little drop in the bandwidth from that of the conventional coupler. This bandwidth reduction is a payback for the significant size reduction.