BANDWIDTH-ENHANCED INTERNAL PIFA WITH A COUPLING FEED FOR QUAD-BAND OPERATION IN THE MOBILE PHONE

摘要

A novel bandwidth-enhanced internal planar inverted-F antenna (PIFA) for quad-band operation in the mobile phone is presented. The proposed PIFA is capacitively excited using a coupling feed, which leads to a dual-resonance excitation in the antenna's lower band at about 900 MHz and a wide-band resonant mode excitation at about 1800 MHz. This makes the operating bandwidths of both the antenna's lower and upper bands larger than 20% (3:1 VSWR), thus easily covering GSM850/900 and DCS/PCS operation. In addition, with quad-band operation obtained, the proposed PIFA occupies a small volume of 5×6×60 mm{sup}3 or 1.8 cm{sup}3 only. Details of the proposed PIFA are described, and results of fabricated prototypes are presented and discussed.