Compact Planar Inverted-F Antenna Built in Gap for Modular phone with Metal Housing

A novel design of planar inverted-F antenna (PIFA) built in gap is presented for modular phone with metal housing. The proposed antenna is designed as a module built in a gap with a thickness of only 7 mm. Two resonant frequencies are yielded by the resonant mode of the PIFA and the slot mode of the metal housing. With the definition of 3:1 VSWR, the antenna achieves a bandwidth covering the operating bands of GSM850 (824~894 MHz), GSM900 (880~960 MHz), GSM1800 (1710~1880 MHz), GSM1900 (1850~1990 MHz), and UMTS (1920~2170 MHz). Good omnidirectional radiation characteristics are obtained within the bandwidth. The proposed antenna can be integrated into a compact volume for modular phone applications.