Dependence of the output phase difference on the asymmetry of 3-dB directional couplers

Abstract

The coupling characteristics of parallel coupled waveguides are examined, with emphasis on the dependence of the output phase difference, by means of a simplified model. The phase relationship among the output waves for a 3-dB coupler is discussed. It is concluded that a magic-T can be realized by employing asymmetric coupled waveguides with a specific degree of asymmetry.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>