A rectangular loop, antenna is proposed for DCS-1800 and IMT-2000 mobile phone handsets. By introducing a small gap in the wire loop, an impedance bandwidth of 24% can be achieved. The antenna mounted on a metal box is simulated using the FDTD method. It is found that the introduction of a small gap also results in a radiation pattern with desirable polarization independence and a reduced gain in the direction of the user's head. The simulated and measured results are presented.
Li, R. L., Tentzeris, E. M., Laskar, J., Fusco, V., & Cahill, R. (2002). Broadband loop antenna for DCS-1800/IMT-2000 mobile phone handsets. IEEE Microwave and Wireless Components Letters, 12, 305-307. https://doi.org/10.1109/LMWC.2002.802031