New High Directivity Coupler Design Using Feed-forward Compensation Technique

Abstract

In this paper, an original high directivity directional coupler is presented. The proposed structure consists of a dual-directional coupler connected at its coupled terminations to a feed-forward compensation circuit. The compensation circuit is used to increase the coupler isolation factor of the obtained directional coupler. The directivity of a commercial dual-directional coupler has been improved by 40 dB using the proposed method.