Improvement of radiation performance of mobile phone antenna using parasitic element

In this paper, we propose a method of using a parasitic element to improve the radio frequency performance of PIFA (Planar Inverted F Antenna) which is built in mobile phone for EGSM, DCS, PCS, and WCDMA bands. The proposed methodology based on external parasitic element in the handset case is validated for extremely thin mobile phone model, which has limited space for any additional parasitic element inside antenna design space. The proposed parasitic element exhibits TRP (Total Radiated Power) and TIS (Total Isotropic Sensitivity) improvement of 0.4 dB to1.1 dB and 0.2 dB to 0.6 dB, respectively, under the free space measurement condition, while 0.6 dB to 0.7 dB and 0.4 dB to 1.1 dB for the hand phantom environment.