Design of a planar monopole multiband antenna with U- and L-shaped slots

A novel planar monopole antenna for multiband operation is presented. The proposed antenna consists of an E-shaped patch and a 50 Ω coplanar waveguide (CPW) transmission line. There are two L-shaped slots cut out of the ground and one U-shaped slot out of the E-shaped patch. By etching the slots, band-rejected filtering properties in the PCS/WiMax bands are achieved. Analysis of the current distribution on the antenna reveals that the addition of the slots creates two stop bands, which is responsible for the multiband properties. This technique is suitable for creating ultra-wideband((UWB) antenna with narrow frequency notches or for creating multiband antennas. This paper presents the design and experimental results of the proposed antenna. Moreover, the study also investigates the tuning effects of the geometry parameters on impedance matching.