Analysis, design, and fabrication of a high-gain low-profile metasurface antenna using direct feeding of Sievenpiper’s HIS

Abstract

Abstract High Impedance Surfaces (HIS) have recently shown the ability to support leaky waves, and to excite plasmonic and HIS resonance frequency modes for use as an antenna. In this paper, we analyzed, designed, and fabricated a true metasurface antenna (TMA) by directly feeding edge-located HIS cells through a microstrip feeding network. In contrast to other metasurface antennas that necessitate an external antenna to excite metasurfaces, our approach is inspired by the TMA design methodology that directly feeds the HIS cells rather than using it as a reflector. We developed a circuit model for the proposed structure and compared the results with those obtained from full-wave simulations. In addition, our further objective was to simplify the structure based on the working principle of the proposed antenna. This objective was achieved by converting square patches into parallel strip lines, leading to an aperture efficiency of about 77%. This simplification also creates additional space to explore various resonant patterns on the top surface and the feeding network on the bottom surface of the TMA. Full-wave simulation results indicate that, despite the compact dimensions of the proposed array with 64 electrically small patch resonators ( $$1.84\lambda \times 1.84\lambda \times 0.032\lambda$$ , where $$\lambda$$ is the free space wavelength at 6.0 GHz), it achieves a realized gain, HPBW (3dB beamwidth) of about 15.1 dBi and $$28^\circ$$ respectively at 6.0 GHz. Finally, we constructed a prototype and conducted measurements to validate the design. Measured results demonstrate good agreement with simulation ones with a gain of about 13.5 (±0.5) dBi and a HPBW of $$27^\circ$$ at 6.0 GHz. The proposed TMA is scaled to fit within the required dimensions for smart handheld devices at higher frequencies (e.g., 54 GHz), while maintaining high gain capability. The design’s scalability, single-feed, and compact footprint make it optimal for diverse wireless communication systems, such as car-to-car (C2C) communications.