Comparison of two flat reflector-type designs for dual-polarization, dual-band operation
July 8, 2001
The parabolic reflector remains an essential antenna for high-gain applications. This is a result of its desirable characteristics based on geometric optics. These include relative frequency independence for sufficiently large apertures and high aperture efficiency. However, the parabolic reflector occupies a large volume. This may be aesthetically unappealing on the sides of buildings and structures. Also, from a mobile user perspective, a desirable characteristic is having a large aperture during operation while having a small volume when packed away and not in use. The parabolic reflector is typically constructed of multiple petals for mobile uses, but it does not pack into as small a volume as a flat, thin antenna would due to the curvature of the paraboloid. Therefore, the primary goal of the antennas studied in this work is developing flat reflector antennas to utilize the advantages of large reflector apertures while remaining capable of packing into a small volume. In addition, system requiremenls dictated dual-band, dual-polarized operation. Two flat reflectors are compared: a reflectarray and a zoned reflector. While each design is inherently narrow-band, methods of achieving dual-band operation were employed.