Design of a Cylindrical Long-Slot Array Antenna Integrated With Hybrid EBG/Ferrite Ground Plane

Two wideband cylindrical long-slot antenna arrays (CLSAs) integrated with hybrid electromagnetic band-gap (EBG)/ferrite ground planes are designed for communication applications in 150-600-MHz (lower) and 0.7-6.5-GHz (upper) bands. The CLSA designs are compact, the lower and upper bands designs´ dimensions being 78 × 63 cm² (height × diameter and 29 × 48 cm², respectively. The hybrid EBG/ferrite ground plane, previously developed and experimentally verified by the authors for planar arrays, was used to both eliminate the slot radiation toward the center of the cylinder and was found to be also important in enhancing the wideband properties of the array. Simulation results show that, under normal operation mode (all array elements have equal phases), the CLSA produces omnidirectional coverage over a wide bandwidth. In challenging environments, the CLSA can also be used in the phased array mode to produce directive and steerable beam patterns. In phased array mode, the beam can be steered 360 ^° field of view (FOV) in azimuth without any distortion in the beam pattern and with more than 10 dB gain increase over the normal operation mode.