Small Antenna With a Coupling Feed and Parasitic Elements for Multiband Mobile Applications

A small antenna with coupling feed and parasitic elements for multiband application is proposed. The proposed antenna is small, low-profile, and suitable for multiband mobile applications. The coupling feed structure provides wideband characteristic to a planar inverted-F antenna (PIFA). There are two resonance modes at 0.8 GHz, and their current distributions are observed. Four resonance modes from high-order resonance modes and parasitic elements are designed to be at 1.7 GHz. The proposed antenna is able to support the GSM850/GSM900/DCS/PCS frequency band in 3:1 VSWR standard. The radiation efficiency and radiation patterns are presented to verify compatibility in mobile handset applications.