Resonant antennas on semi-infinite and lens substrates at terahertz frequency

Abstract

This part is concerned with four different types of resonant antennas on semi-infinite and lens substrates made of high-permittivity dielectric materials at terahertz frequency. Full-wavelength single-dipole, full-wavelength dual-dipole, half-wavelength single-slot, and full-wavelength four-leaf-clover-shaped dipole antennas are studied at a frequency of around 1.0 THz. The resonance characteristics of the four antennas are first investigated on a semi-infinite substrate, using the method of moments simulator FEKO. Based on these characteristics, the antennas are placed on an extended hemispherical lens to examine and compare the radiation effects of a substrate lens on each antenna, using the finite-integration time-domain simulator CST Microwave Studio. The shape of an extended hemispherical lens with optimum thickness and quarter-wavelength matching layer plays an important role in maximizing the directivity, while the radiation efficiency is generally affected by the antenna structure.