A LOW-PROFILE MONOPOLE ANTENNA EMBEDDED WITH A RESONANT SLOT

A low profile dual-band mobile phone antenna with a very small volume of 0.768 cm(3) (40 x 4 x 4.8 mm(3)) is presented. The antenna is formed by a monopole and an open-end slot embedded therein. The impedance bandwidths for the lower and upper bands with a definition of 3 : 1 VSWR (6 dB return loss) reach 215 MHz (815-1030 MHz) and 515 MHz (1660-2175 MHz) respectively. Furthermore, small excited surface current distributions on the ground plane of the antenna are achieved, and the ground plane length has smaller effect on the achievable bandwidths of the antenna compared with the conventional internal patch antennas for mobile phones, which make the antenna very attractive to be applied to the mobile phones with various possible ground plane lengths. Good radiation characteristics over the operating bands are obtained.