Design of a Modified Monopole Antenna for the Quadband Communication

A modified monopole antenna is proposed for multi-band personal wireless communication handsets with triple-resonant operation. This antenna consists of a main radiator, a bent tuning stub, an U-shaped slit, a shorting strip line, and a narrow resonant slit, and occupies a total volume of 36 x 15.8 x 6 mm(3). The first resonant frequency is decided by the main radiator of the antenna, and the second one is controlled by the length of a bent tuning stub. The third resonant frequency is generated by inserting a narrow resonant slit in a perimeter of the main radiator. Three resonant frequencies of the designed antenna can be independently controlled by tuning the length of individual element of the proposed antenna. The bands of the implemented antenna are GSM900, DCS1800, US-PCS, and S-DMB.