Single-Glass Layer Optically Transparent Transmitarray With High Aperture Efficiency And Low Profile At 5G Millimeter-Wave Band

This communication presents a single-glass layer optically transparent transmitarray (TTA) with high aperture efficiency at millimeter-wave (mmWave) 5G band. When designing a transmitarray (TA), the more metal and dielectric layers used, the easier it is to increase the aperture efficiency. However, if the TTA is designed, the fewer metal and dielectric layers, the more advantageous it is in terms of optical transparency (OT). Therefore, only single glass layer was chosen to design a TTA with high OT. The novel analysis technique was applied to obtain theoretical transmission response of the single substrate unit cell and to obtain impedance information to quickly design unit cells by combining circuit analysis. Then, the aperture efficiency was increased using two methods: (1) two types of double resonance unit cells were combined, (2) oblique incidence on the unit cells on the edge of TA aperture was considered. The designed TA was converted into the TTA, which satisfies advanced OT guidelines proposed in this communication. The fabricated TTA has a focal length (F) to dimension (D) ratio of 1.2, exhibiting simulated and measured aperture efficiencies of 51.1% and 45.3%.