Abstract
A near-field focused folded transmitarray antenna is proposed at 2.45 GHz for medical applications. The folded construction introduces compact design and low fabrication cost for the transmitarray. Also, the near-field focusing technique introduces the same far-field pattern in the transmitarray near-field which introduces more compactness in the design. The transmitarray consists of a feeding horn antenna embedded centrally in the transmitarray and a perfect electric conductor plate with the same size acts as a reflector. The radiation from the feeding horn is reflected by the plate toward the transmitarray. The unit cell of the transmitarray is a square dielectric box with four identical circular holes designed for 320A degrees transmission coefficient phase variation with nearly -3 dB coefficient magnitude. The radiation characteristics of the unfolded and folded transmitarray are analyzed using the finite integral technique. Near-field focused folded transmitarray is designed. The focal plane is very close to the near edge of the Fresnel region for medical applications. The normalized power density distribution on a part of the human leg placed in front of the transmitarray is investigated.