Small Internal Antenna Using Multi- and Wide-band and High-Isolation MIMO Techniques

Abstract

In this thesis, a small internal antenna for a mobile handset is presented using multi- and wide-band and high-isolation multiple input multiple output (MIMO) techniques. The proposed antenna consists of three planar inverted-F antennas (PIFAs) which operate for GSM (0.88 � 0.96 GHz), DCS (1.71 � 1.87 GHz), PCS (1.85 � 1.99 GHz), UMTS (1.92 � 2.17 GHz), and WLAN (2.40 � 2.48 GHz) bands with the size of 40 x 10 x 10 mm3. A resonator attached to the folded PIFA creates dual resonances for wide bandwidth about 460 MHz covering DCS / PCS / UMTS bands, and a meander shorting line is used for improving impedance matching. Additionally, a modified neutralization line is embedded between diversity antennas to enhance isolation, which results in 5 to 6 dB improvement of isolation. Simulation and measurement results for S-parameters and radiation patterns are agreed very well. The peak gains show 3.73, 3.77, 3.28, 2.22, and 5.86 dBi at GSM, DCS, PCS, UMTS, and WLAN, respectively.