Wide Band Gain Enhancement of a mm Wave Conical Horn Antenna with a Metamaterial Lens

Abstract

In this work, a two-layer grid wire metamaterial structure is proposed for the gain enhancement of a conical horn antenna. It has smaller size and lower-cost compared to conventional horn solutions. Flat metamaterial structure is implanted to the aperture of the horn. It focuses electromagnetic energy and behaves like a circular flat lens. It consists of two regions with different electrical properties. At the outer region of the circular metamaterial lens, electrical permittivity is near zero, whereas at the inner region it is positive (free space). The phase distribution is controlled by the structure of meta material lens and energy if focused. The designed antenna is numerically investigated with a full-wave analysis tool. The results show gain increase up to 2.2 dB within 72–86 GHz frequency band compared to traditional conical horn with the same physical size (5λ0at 79 GHz). This antenna may be a good solution for the applications such as satellite, radar and remote sensing where directive antennas are required.