MULTIPLE ANTENNA SYSTEM FOR MOBILE HANDSET APPLICATION

Abstract

In this thesis, a multiple antenna system for mobile handset application is proposed and implemented. The overall dimensions of the substrate are 48 mm × 108 mm × 0.8 mm, which are suitable for simulating a practical mobile handset. The proposed multiband antenna consists of a PIFA for mobile operation and a MIMO antenna with a decoupling network for WLAN operation. Additional resonance is generated in the 2-GHz band by adding a λ/4 open stub to the PIFA, thus improving the impedance matching characteristics of the antenna. In order to improve the isolation between the PIFA and MIMO antenna elements, each element is placed at the corner of the ground plane. In addition, a decoupling network is added to the feeding line of a shorted monopole antenna element. The measured results show that the proposed antenna can cover GSM/DCS/PCS/UMTS and WLAN bands, simultaneously. The fabricated antenna has the isolations of about 15 dB at 2 GHz and 5.8 GHz band while over 18 dB at 5.2 GHz band. The peak gains of the two antennas are 5.31 dBi and 4.44 dBi at 2.44 GHz band, 5.55 dBi and 4.92 dBi at the 5.25 GHz band, respectively. The ECC of the two antennas is maintained below 0.05 over the entire frequency bands of interest. Experimental results show that the proposed antenna can be used in future wireless applications such as mobile handsets and smartphones.