A circulator/isolator assembly is disclosed. The assembly includes a first magnetic substrate having first surface and a second surface and a first ground plane formed on the first surface. A dielectric layer is disposed adjacent first magnetic substrate. The dielectric layer includes a multi-port junction circuit coupled to transmission traces. One of the traces forms an input port and another forms an output port. A first magnet is disposed proximate the multi-port junction circuit of the dielectric layer. The first magnet excites a circular, unidirectional magnetic flux field in the first magnetic substrate that limits electromagnetic wave propagation to a single direction.