Marco Letizia

OBLIQUE INCIDENCE DESIGN OF MEANDER-LINE POLARIZERS FOR DIELECTRIC LENS ANTENNAS

A method to design planar multilayer meander-line polarizers is given. The proposed procedure is based on transmission line circuit theory and on full-wave unit cell analysis in frequency domain. The hybrid combination of those two techniques paves the way for the polarizer design process and avoids heavy full-wave optimizations. This procedure is originally aimed for polarizers acting on lens antennas and is suitable for plane waves impinging with arbitrary angles on the polarizer. To validate the proposed method, two polarizers have been manufactured in Ka-band, one for normal and one for oblique incidence. Designs, prototypes and measurements made on a complete Ka-band lens antenna subsystem are shown in this paper.

Design of an Ultra Wideband Universal Serial Bus device mounted antenna

The present paper reports on the simulation, construction and measurement of a planar Ultra Wideband (UWB) monopole antenna designed to operate inside a Universal Serial Bus (USB) dongle, aiming at usage in industrial applications. Inexpensive FR4 substrate with εr = 4.4 and 0.8 mm thickness was used and the antenna shape and dimensions fit in a common case. The built antenna prototype was tested inside a USB device case in free space and in a realistic antenna deployment scenario, with the dongle connected to a laptop computer. It was found that the designed antenna exhibits acceptable |S11| matching in the frequency range [2.5; 12] GHz, allowing its usage in UWB and other wireless services such as Bluetooth, LTE and IEEE 802.11.

Prolate ellipsoidal lens for antenna systems providing multiple asymmetric beams

A 3-D shaped prolate ellipsoidal dielectric lens is designed to produce multiple asymmetric beams in Ka-band. Such radiation characteristics are useful in applications where the antenna system is mounted on platforms ∞ying above Earth and the shape of the footprints have to be carefully controlled for difierent elevation angles. A set of design rules is introduced and the flnal designs are optimized using full-wave time-domain methods. A fully operational Ka-band antenna subsystem has been prototyped and measured. The flnal antenna lens has axes lengths of 62.3mm and 57.8mm and provides a maximum gain of 21dB. When mounted on a stabilized platform at the altitude of 21km (a typical HAPS scenario), this antenna provides 19 circular ground footprints of 5km diameter each. Radiation pattern measurements show that such a lens reduces the natural beam footprint elongation unavoidable with traditional spherical lenses and conflrm the validity of the proposed system.