Three-section asymmetric differentially-fed broadband coupled-line directional coupler

A design of a differentially exited directional coupler with the utilization of balanced lines is shown. An edge-coupled stripline technology is proposed for its physical realization. Such a realization technique is for the first time proposed for the design of multisection asymmetric couplers. For experimental verification a coupler operating between 0.29 and 1.7 GHz has been manufactured and measured.