A Dual-Band Terahertz Leaky-Wave Meta-Antenna

A leaky-wave meta-antenna (LWMA) is first proposed for high-gain co-aperture control of dual-band terahertz (THz) waves, where the meta-slots enable independent full-phase manipulation of two orthogonal waves at distinct frequencies. When used as a transmitting antenna, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</i>- and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i>-polarized guided waves at the frequencies of 0.14 THz and 0.0972 THz, respectively, are coupled into the parallel-plate metal waveguide via two separate waveguide input ports. The two guided waves are manipulated simultaneously and independently by the meta-slots, enabling directional radiation through a shared aperture. The far-field gains are 35.1 dBi at 0.14 THz and 32 dBi at 0.0972 THz, with aperture efficiencies of 43.8% and 44.6%, respectively. The corresponding cross-polarization levels are –42.8 dB and –31.2 dB below the main lobes, and the isolation levels are as low as –31.3 dB and –31.1 dB. When operated in reverse as a receiving antenna, it converts the two orthogonally polarized incident beams into two-dimensional guided waves, which are then focused onto two distinct receiving ports. The gains at the focal points are 27 dB at 0.14 THz and 26.3 dB at 0.0972 THz. Both the measured far-field radiation patterns and intensity distributions on the focal planes agree well with the simulation results. The dual-band THz LWMA is promising for applications in sixth-generation mobile communications, radar detection, and imaging.