An inverted-L antenna based on finite ground plane with zigzag structure

A key focus of this paper is to investigate the influences of finite ground plane on the monopole inverted-L antenna in mobile phone. Based on this, a ground plane with a zigzag parasitic structure is originally proposed, combined with a typical inverted-L antenna, the overall novel structure overcomes the issues of low radiation efficiency and impedance mismatching caused by the finite ground plane in compact status. At GSM 900 band, the minimum value of Sn decreases to -27.5dB from -5dB, and the relative bandwidth of such new antenna reaches to 24% (VSWR<;2), which is about three times as wide as that of the conventional monopole inverted-L antenna, effectively expanding the monopole antenna's bandwidth, and making it a great potential in practical application.