Very low-profile "Bull's Eye" feeder antenna

Abstract

In this letter, a very low-profile planar horn antenna is proposed. It consists of a subwavelength aperture placed into a "Bull's Eye" concentric periodic corrugated conducting plate that produces good return losses and a narrow radiated beam. The antenna is excited by means of a waveguide whose flange has been properly mechanized in the rear part of the structure. The mechanism explaining this phenomenon is similar to the enhanced transmission observed at optical wavelengths in similar structures. In this work, the circularly corrugated structure has been scaled into the microwave frequency range and, moreover, the plane wave excitation has been replaced by a subwavelength aperture excited by a conventional closed metallic waveguide. This transforms the original focusing structure into a new concept of a very low-profile feeder with potential applications.Index Terms-Bull eye, concentric periodic corrugated plate, metamaterials, subwavelength aperture, very low-profile feeder.

3-D-Printed 96 GHz Bull’s-Eye Antenna With Off-Axis Beaming

“…Thus, as observed in [23], at a sufficiently large number of periods, the increase of the gain for consecutive number of grooves will be negligible. This was also reported in [26] and very recently in [31]. P=3 P=4 P=5 P=6 P=7 P=8 P=0 P=1 P=2 P=3 P=4 P=5 P=6 P=7 P=8 P=0 P=1 P=2 P=3 P=4 P=5 P=6 P=7 P=8 P=0 P=1 P=2 P=3 P=4 P=5 P=6 P=7 P=8 P=0 P=1 P=2 P=3 P=4 P=5 P=6 P=7 P=8 P=0 P=1 P=2 P=3 P=4 P=5 P=6 P=7 P=8 P=0 P=1 P=2 P=3 P=4 P=5 P=6 P=7 P=8 P=0 Fig.…”

“…These antennas consist of a radiating slot surrounded by straight parallel [23]- [25] or annular concentric [26] corrugations. In the latter case, the structure is usually called Bull's-Eye (BE) antenna.…”

Additive manufactured millimeter wave off-axis bull's-eye antenna

“…It was chosen to include only P = 7 rings, as it was found to be a good tradeoff between size and gain. A higher gain is not necessarily obtained with an increasing number of periods, as reported in [7], [8], [14].…”

“…The metallization of the antenna was modelled as bulk Copper (σ = 5.8×10 7 S/m). The antenna follows a design process similar to previous antennas [7], [8] where a metallic slab is perforated by a central aperture, whose dimensions (s x × s y × s z ) fix the frequency at which the power, fed by a waveguide attached to the rear part, will be coupled to a TM surface wave. In this case, the slot's width (1.627 mm) and the height (0.470 mm) fix the operating transversal resonance and its Q-factor, whereas the slot's depth (0.77 mm) locates the longitudinal resonance at higher frequencies.…”

“…Nevertheless, most of the metalbased structures antennas [7]- [10] present a weight which might be a handicap for applications where light-weight is an issue is directly linked to the cost, as satellite or drones deployment. 3D printing is already proving useful in several everyday areas like prosthesis, in the automotive sector or even in the toy industry.…”