Metallic waveguide transmitarrays for dual-band terahertz antennas with high gain and low sidelobe levels

The antenna is an indispensable device in terahertz (THz) wireless communication systems. Owing to the high propagation attenuation of THz waves in atmospheric, THz antennas with high gain and low sidelobe levels (SLLs) are in an urgent need. Here, a metal waveguide transmitarry antenna (MWTA) is proposed to realize high gain and low SLLs at dual THz bands simultaneously. At the frequencies of 0.14 and 0.0972 THz, the peak gains are 32 and 28 dBi, the SLLs are both 21 dB lower than the main lobe, and the 3 dB beamwidths are 4.4° and 5.7°, respectively. As a proof of concept, a prototype with a diameter of 48 mm is fabricated and the measured results are in good agreement with the simulations. The proposed MWTA with high gain and low SLLs at dual THz bands holds great application potential in 6G wireless communication, non-destructive testing, and biomedicine.