Compact and wide-band Quasi Yagi-Uda antenna based on periodic grating ground and coupling method in terahertz regime

• Published in: Optik (Stuttgart) 2020-02, Vol.203, p.163990, Article 163990
• Main Authors: Poorgholam-Khanjari, Shima, Zarrabi, Ferdows B., Jarchi, Saughar
• Format: Article
• Language: English
• Subjects: Bandwidth enhancement; Compact antenna; Grating layer; Quasi Yagi-Uda antenna; THz antenna
• ISSN: 0030-4026; 1618-1336
• DOI: 10.1016/j.ijleo.2019.163990

We are supposed to design a compact antenna and improve the bandwidth of a planar Quasi Yagi-Uda Antenna in the Terahertz band by the periodic ground layer and parasitic metamaterial elements. For these goals, we suggest the grating structure for the ground plane to dispense the current of the antenna to attain higher impedance matching and two concentric rectangular parasitic loops are used to improve it. The ground plane is altered to improve bandwidth enhancement and provide size reduction. In this structure, a dipole driver is exploited on both sides of a transparent glass with refractive index of 1.95 and thickness of 1 μm as the substrate, and a microstrip-line is utilized for feeding the dipole element. The structure is optimized by parametric studies and parameters for the best performance are presented for achieving higher bandwidth. We compact this antenna size more than 42.2 % in comparison normal antenna while the bandwidth is achieved more than 27 % at 1.84–2.42 THz. Thus, this antenna can be used for various applications in the THz spectrum such as the medical imaging and THz communication systems for early skin cancer.