Full-wavelength dipole antenna on a membrane covered with a lens for a high gain terahertz photomixer

This paper presents a full-wavelength dipole antenna on a membrane covered with a lens to improve the efficiency and directivity of a terahertz photomixer. A full-wavelength dipole antenna supported by a membrane structure has low directivity. An extended hemispherical lens introduced in front of the antenna can achieve high directivity. The optimized antenna had a 3818-Ω input resistance and a 71.2% radiation efficiency at the 1.07-THz resonance frequency. The total efficiency of this structure is approximately 6.8 times that of a full-wavelength dipole antenna with almost the same directivity.