Symmetrical metal-rimmed mobile antenna with decoupling network for penta-band

Abstract

A symmetrical metal-rimmed mobile antenna, which is designed to be separated into two antennas covering different bands, is proposed for penta-band in this letter. The proposed antenna consists of a gap-coupled quarter wavelength loop antenna to reduce the length of an antenna and a decoupling network of 90 degrees delay line to improve an isolation in the low band. Its resonant frequencies in low and high band can be controlled by the length of a feed line and a lumped series inductor, respectively. Since the slit of the metal rim is located at the center of the phone, the designed metal-rimmed antenna could be less affected by the hand compared to the case where the slit is located on the side of the phone. To verify the performance, we have simulated and measured the characteristics of the proposed antenna without and with the decoupling network such as reflection coefficients, far-field radiation patterns, and total efficiencies. Good agreement between the simulated and measured results is obtained.