Compound Fresnel Zone Lens Conformal to Truncated Cone: Antenna Application |
| |
Authors: | H D Hristov L P Kamburov R Feick and J R Urumov |
| |
Institution: | (1) Departamento de Electrónica, Universidad Técnica Federico Santa María, Av Espa?±a 1680, Valparaíso, V Region, 110-V, Chile;(2) Department of Radiotechnics, Technical University, Varna, 9010, Bulgaria |
| |
Abstract: | A millimeter wave antenna consisting of two Fresnel zone plate lenses, plane and conical, is examined numerically by use of
the vector diffraction theory. The lenses are of Wood-Wiltse (double-dielectric) or Soret (half-open) type, and are designed
for the frequency of 117 GHz. The lenses are made conformal to a truncated circular cone with a base diameter of 500 mm and
a plateau diameter of 250 mm. Designs for two opening semi-angles, 45° and 75° each of them with a particular lens thickness
are presented. For the angle of 90° the cone lens becomes a plane ring lens, which in combination with the plateau zone lens
forms a plane lens of size equal to the cone base diameter. Illuminated by directive feeds set at a focal distance of 525 mm
from the cone apex, the double-dielectric and half-open compound and plane lenses, form three pairs of Fresnel zone lens antennas,
the co-polar and cross-polar radiation characteristics of which have been compared numerically. The double-dielectric lens
antennas examined are about 5 dB superior in gain to the half-open lens antennas, which has a gain of approximately 45 dBi.
Because all lenses are of equal transverse aperture, the corresponding lens antennas exhibit the same −3 dB beamwidth of about
0.33 degrees. The plane zone lens antenna is very thin and simple. Instead, the antenna comprising a 3-D compound Fresnel
zone lens is thicker but can be made conformal to a specific surface shape and possesses more levels of design and optimization
freedom. |
| |
Keywords: | Wave focusing Electromagnetic lenses Fresnel zone plate lenses Fresnel zone antennas |
本文献已被 SpringerLink 等数据库收录! |
|