Broadband design of a low-profile reflector antenna

This work presents the design and analysis of a modified Fresnel zone plate reflector for broadband operation. A new technology based on slight deformations on a flat metallic surface is applied to obtain the geometrical model of the proposed flat reflector antenna. In comparison with reflectarrays, Fresnel zone reflectors are lossless, low cost, easy to fabricate and broadband. According to the specifications of a previously published reflectarray, a centre-fed prototype whose dimensions are 28 x 21 cm has been designed and analysed showing a maximum gain of 28.06 dBi at 12.5 GHz and a 32.8% 3 dB gain bandwidth in the range between 10.4 and 14.5 GHz. A second prototype has been designed and analysed to evaluate the performance of the proposed design method compared with a previous design of a Fresnel zone reflector. Better results in terms of gain and antenna efficiency have been obtained.