Analysis and design of couplers using artificial transmission line

Compact Branch line and Rat-race coupler are analyzed and designed using Artificial Transmission Line (ATL). The couplers are designed to operate at center frequency of 2.5GHz using commercially available FR4 material. Properties are analyzed using IE3D simulation tool. Conventional couplers are also analyzed for comparison purpose. Couplers using ATL show 40% size reduction compared to conventional couplers. ATL Branch line and Rat-race coupler have similar frequency response as that of conventional couplers.