Abstract This work reports the development of a simple, low-profile and ultra-wideband printed antenna. The proposed antenna is based on a truncated ground plane and an impedance matching structure formed by a round junction and two chamfers; these modifications significantly increase the antenna frequency bandwidth compared to conventional microstrip antennas and ultra-wideband printed monopoles published in literature. An antenna prototype was fabricated using an Arlon DiClad 880 substrate with an electrical permittivity of 2.2. A bandwidth of 176% was attained at a central frequency of 14.9 GHz (ranging from 1.79 to 28.02 GHz). Numerical simulations and experimental results of the antenna's radiation pattern are also reported and exhibit good agreement. To the best of our knowledge, this is the widest bandwidth from a printed antenna that has been published in the literature.

The work investigates the electromagnetic performance of omnidirectional dual-reflector antennas designed to operate with a frequency bandwidth larger than 45% (25-40 GHz). We consider two antenna configurations, distinguished from each other by two different optical ray mappings. A conventional coaxial horn is designed to ensure vertical polarization and stable primary radiation pattern along the operating bandwidth. By employing a geometrical optics synthesis technique, the omnidirectional reflectors are shaped to maximize the directivity of the broadside secondary radiation patterns. For the synthesis, we employ different aperture power distributions and investigate their effect on the antenna gain and return loss when operating over the 40% frequency bandwidth. To access the antenna performance, a full-wave electromagnetic analysis based on the combination of mode matching and method of moments is employed.