Coupled-line 180° hybrid coupler

Abstract

A new 180° hybrid-coupler structure based on coupled lines is proposed. It consists of two quarter-wave coupled-line sections and one half-wave transmission-line section. The coupled outputs are always in phase with the input signal for all ports, and the through or direct outputs are either in phase or out of phase from the input signal, depending on the input ports. It has a simple structure and wide bandwidth, and can be implemented over a wide range of coupling values. © 2005 Wiley Periodicals, Inc.