Research Information System
7. BİLSEL INTERNATIONAL GORDİON SCIENCE RESEARCHES CONGRESS, Ankara, Turkey, 25 - 26 October 2025, pp.88-95, (Full Text)
This work presents a three-layer frequency-selective-surface (M-FSS)–based transmitarray antenna unit cell operating at a 0.29 THz center frequency, together with its array implementation that produces a fixed beam at 0°. The proposed cell achieves full 360° transmission-phase coverage by varying only a single geometric dimension within a specified range; all design steps and validations are carried out in CST using full-wave simulations. For cell–array integration, the classical lens phase law is employed; via a “target-phase to cellparameter” mapping, the phase distribution is assigned to a square aperture with 11×11 elements, a period of 0.322λ₀ (333 µm), and F/D = 0.6. The array is fed by a horn antenna, and array-level phase maps and far-field patterns are generated. Simulation results indicate a peak realized gain of 16.96 dBi at 0.29 THz, while the highest sidelobe level is - 18.96 dB. Under the same setup, the aperture efficiency—computed from the physical aperture area and the peak realized gain—is 31.5%. The presented workflow links a fabrication-friendly M-FSS unit cell that provides continuous phase coverage with a transparent phase-to-parameter mapping for array synthesis, demonstrating array-level performance for a fixed 0° beam via simulation. In conclusion, a compact horn-fed transmitarray achieves a stable, narrow beam in the 0° direction. The study outlines a low-profile, application-oriented design path in the terahertz regime.