LAUSR

This paper proposes a miniaturized monopole ultra-wideband antenna with single-frequency rejection. The recommended antenna size is reduced from 58 × 54 mm2 to 32 × 54 mm2 by the half-cut method. The bandgap design is achieved by placing a dual mushroom type electromagnetic bandgap (EBG) structure on the side of a coplanar waveguide feeding line. The equivalent circuit and surface current distribution were used to analyze and explain the effects of mushroom-like EBG cells and the principle of the half-cut method. Both the prototype antenna and the proposed antenna have been fabricated and tested. From the measurement results, the proposed antenna exhibits good band-stop characteristics and can reject the wireless LAN interference band (5.2 and 5.8 GHz bands). Furthermore, the proposed antenna has considerable gain over the entire operating frequency band except for the notch band.