| Modern satellite and mobile communications systems continue to push the bandwidth capabilities of antenna subsystems. Printed microstrip architectures have been widely investigated and are attractive for their conformability, small size and cost effectiveness. While vigorous research activity over the past two decades has improved the bandwidth of microstrip elements to upwards of 30%, this is still not adequate for future system demands. An architecture, which can meet these difficult bandwidth requirements, is undergoing a resurgence in research interest, that being the double-sided printed-dipole.; Though not truly a microstrip device, due to its relatively large ground plane spacing and balanced feed line, it shares many similarities with the classic microstrip structure. Primarily, they are both printed devices. However, unlike the more common microstrip antenna element, which is severely limited by its bandwidth, the double-sided printed-dipole possesses a very wide operational bandwidth. Configurations using arrays of this type of structure were described in the literature, however, no detailed analysis or comprehensive measurements were provided. The starting point was therefore to consider and analyze a recently reported topology of double-sided printed-dipoles.; A 32-element wideband printed-dipole array was fabricated, analyzed and successfully optimized for improved bandwidth performance in excess of an octave. Various aspects of the architecture, which control the performance of the antenna, have been investigated including the wideband balun and launcher system. A balun test arrangement was devised which yielded valuable results. The array's height over the ground-plane was determined to have the greatest effect on maximum bandwidth, while mutual coupling was determined to be less significant. Excellent correlation between simulated and measured radiation patterns was observed. An improved wideband antenna element has been developed for future exploitation. |
