Closed-Form Relation between the Scan Angle and Feed Position for Extended Hemispherical Lenses based on Ray-Tracing
2016 (English)In: IEEE Antennas and Wireless Propagation Letters, ISSN 1536-1225, E-ISSN 1548-5757Article in journal, Letter (Refereed) Published
This letter presents a closed-form relation between the scan angle and feed position for extended hemispherical lenses. This relation is derived using ray-tracing, and it is valid for both large and small scan angles, in excellent agreement with fullwave simulations. It is demonstrated that the relation is linear in the small-angle limit, and the effective focal length determining the scan angle is presented. It is also demonstrated that the scan angle only depends on the geometrical configuration, and that it is independent of the lens material. To demonstrate the applicability of this scan angle relation to the design of focal plane arrays (FPAs), we demonstrate that it can be used to determine the FPA spacing that results in -3 dB overlap between switched beams. A comparison with full-wave simulations of lenses with varying materials and FPA elements demonstrates a root mean square (rms) accuracy of 0.27 degrees for the scan angle estimation, and rms accuracy of 0.26 dB for the -3 dB overlap criterion between the central and adjacent beams. Finally, we present scaling rules which show that the scan resolution is inversely proportional to the lens diameter, whereas the FPA spacing is independent of the total lens size.
Place, publisher, year, edition, pages
IEEE Press, 2016.
Ray-Tracing, Extended Hemispherical Lens, Beam Steering, Focal Plane Array (FPA), antenna theory, lenses
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-197334DOI: 10.1109/LAWP.2016.2545858OAI: oai:DiVA.org:kth-197334DiVA: diva2:1051802
QC 201612122016-12-032016-12-032016-12-19Bibliographically approved