Planar, high-gain, substrate-integrated cavity antenna in the terahertz frequency range

In this paper, we propose a planar and highly directive cavity type of antenna in the terahertz frequency range. The antenna consists of a frequency selective surface (FSS) and an open-ended narrow slotline dipole, which are both lithographically patterned on a high-permittivity gallium-arsenide substrate. The FSS in conjunction with the ground plane of the slitline forms a Fabry-Perot resonator and results in significant directivity enhancement. The simulation results show that the substrate volume determines the effective permittivity of the cavity for the resonance operation. The optimized antenna, which has a size of about 3600 μm × 3600 μm × 175 μm, produced a maximum gain of 14.6 dBi, a radiation efficiency of 55%, and side lobe levels of -14.0 dB and -16.4 dB in the two principal planes at a resonance frequency of 317 GHz.