Development of an electrically small one-sided directional antenna with matching circuit

We designed an electrically small antenna (ESA) with coplanar waveguide (CPW) matching circuit. Matching circuit is realized by using interdigital gap and transmission line. Our ESA has one-sided directivity for IMS band application. By using and controlling the length of floating metal layer on the bottom side, we can realize the one-sided radiation on the thinner substrate than that of the standard patch antenna. We also made experiments on the ESA with CPW matching circuit using patterned circuit board.