Design of an Internal Multiresonant Monopole Antenna for GSM900/DCS1800/US-PCS/S-DMB Operation

A design is proposed of a multiresonant monopole antenna for a personal wireless communication handset. Multiresonant operation is achieved through the use of a bent tuning stub, a shorting strip line, a U-shaped slit and the addition of a narrow resonant slit to the main radiator. The first resonant frequency is determined by the main radiator of the proposed antenna, and the second resonant frequency is controlled by the length of the bent tuning stub. The third resonant frequency is generated by adding a narrow resonant slit to the perimeter of the main radiator. The three resonant frequencies of the designed antenna can be independently controlled by tuning the length of the individual elements of the proposed antenna. The measurement shows the intended four wireless communication services: global system for mobile communication (GSM900), digital communication system (DCS1800), US-personal communication system (US-PCS), and satellite-digital multimedia broadcasting (S-DMB). The proposed antenna is small enough to be built into a practical wireless mobile handset. The parameters determining the antenna´s multiresonant characteristics are analyzed, and experimental results of the constructed prototype are presented and discussed.