Design of Terahertz Detection Antenna With Fractal Butterfly Structure

Terahertz (THz) technology can be widely used in radar, remote sensing, homeland security and counter-terrorism, high-secret data communication and transmission, atmospheric and environmental monitoring, real-time biological information extraction, and medical diagnosis. It is the frontier of current research. However, most of highly sensitive THz detectors work in a relatively narrow frequency range. It attracts great attention to design a high-gain terahertz antenna which operates in a wide spectrum range. In this paper we propose a new structure of fractal butterfly antenna with high gain which can be used for broadband THz detection. This fractal butterfly antenna is constructed by independent fractal unit groups on butterfly antenna, which simplifies the antenna manufacturing process and reduces the manufacturing cost. The antenna can operate in the 0.1-10 THz frequency band, with impedance bandwidth of 85% resonated at 4.9 THz, return loss of as small as −33.59 dB, and maximum gain of 16.95 dB. Among the antenna with 3 to 4 fractal unit groups, the best operation band of the antenna is 6.2-6.4 THz. The proposed fractal butterfly antenna can effectively improve the performance of terahertz detectors, and provide the possibility for detection research in higher frequency bands.