Reconfigurable Annular Ring Slot Antenna with Circular Polarization Diversity

In this paper, the reconfigurable annular ring slot antenna with circular polarization diversity is proposed for SDMB(satellite digital multimedia broadcasting) system. The proposed antenna consists of a ring slot with tuning stubs. Four PIN diodes are attached to achieve circular polarization diversity. By switching the diodes on or off, the proposed antenna can be operated either RHCP(right hand circular polarization) mode or LHCP(left hand circular polarization) mode. The experimental result shows that the proposed antenna has an impedance bandwidth( VSWR les 2 ) of 2.47~3.04 GHz(570 MHz) at LHCP mode, an impedance bandwidth( VSWR les 2 ) of 2.45~3.01GHz(560 MHz) at RHCP mode, a maximum gain of 3.1dBi at RHCP mode, 4.76dBi at LHCP mode. The 3dB CP bandwidth of about 100 MHz at both RHCP and LHCP mode is achieved at the center frequency 2.63 GHz. The proposed antenna is suitable for application such as mobile satellite communications, WLAN(wireless local area networks), and broadband wireless communication systems.