The design and performance of low-profile, multiple-feed metasurface antennas with different numbers of patch cells and different substrate thicknesses at a terahertz frequency are presented in this paper. The utilized antenna designs consist of a periodic array (N × M) metallic square-patch metasurface and a planar feeding structure, which are both patterned on an electrically thin, high-permittivity GaAs substrate. The antenna gain increased in a linear fashion with an increasing number of patch cells, which were directly fed by the slit feedline. A 3-dB gain increment was observed irrespective of the substrate thickness when the number of patch cells was doubled. However, the 3-dB gain bandwidth as well as the radiation efficiency changed significantly with varying substrate thicknesses. The described antenna structure offers useful characteristics by means of a combination of different substrate thicknesses and patch numbers. In addition, the proposed antenna design features a number of benefits, including a low profile, mechanical robustness, easy integration into circuit boards, and excellent suitability for low-cost mass production.
This work was supported in part by Institute for Information & Communications Technology Promotion (IITP) grant funded by the Korea government (MSIP) (No. 2017-0-00959, University ICT Basic Research Lab), in part by \u201cHuman Resources Program in Energy Technology\u201d of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20164030201380), and in part by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (2016R1A2B100932).