Design of a 2-Bit Reconfigurable UWB Planar Antenna Array for Beam Scanning Application

Reconfigurable antennas have been widely employed for beam scanning in recent years. However, such antennas are usually limited by narrow bandwidth. To overcome this challenge, we present a linearly polarized 2-bit ultra-wideband (UWB) antenna array in C-band. The antenna array consists of 16 Vivaldi elements, 16 wideband phase shifters and a feeding network. The structural symmetry is employed to provide a couple of opposite phase states in the broad bandwidth. The measured results show that the antenna array can operate well in a broad bandwidth from 4.0 to 5.5 GHz (the relative bandwidth ~31.5%) with reflection loss lower than −10 dB. The scanning angle ranges from −45° to 45° with the sidelobe below −10dB, which agrees well with the theoretical predictions. The design features low cost, simple structure, easy fabrication and broad bandwidth.