Broadband UHF Directional Coupler with High Directivity

A novel microstrip directional coupler operating at UHF band from 1 to 3 GHz is presented. The coupler was designed using 3D electromagnetic simulations. FR4-type dielectric substrate has been used due to its low cost. The proposed directional coupler provides a directivity of at least 22 dB and has an almost flat coupled power of −15 dB at the coupled port.