Complementary Phase Power Divider Feed for Dipole Antenna Specific to GSM 900 Base Station Applications

Power Divider (PD) design intended for feeding dipole antenna meant for Global System for Mobile Communications (GSM) 900 applications with an antenna height of 22 mm, operating in the frequency range of 880~960 MHz is presented herein. The PD provides 3 dB power division along with complementary phase at its output. The out of phase division of power divider is obtained by utilizing the concept of defected ground structures. A slot line accompanied by T-junction makes up the defected ground region, while coupled microstrip lines form the feed positions. The simulated and the measured results are in good coherence. PD shows good return loss and low insertion loss. It is observed that the dual polarized base station antenna has VSWR below 2 in the required frequency range, 10 dB gain and port to port isolation is less than 22 dB. The antenna is dual polarized and a + or - 45 degrees polarization is maintained.