High performance antenna-on-chip inspired by SIW and metasurface technologies for THz band operation

In this paper, a high-performance antenna-on-chip (AoC) is implemented on gallium arsenide (GaAs) wafer based on the substrate integrated waveguide (SIW) and metasurface (MTS) technologies for terahertz band applications. The proposed antenna is constructed using five stacked layers comprising metal-GaAs-metal-GaAs-metal. The conductive electromagnetic radiators are implemented on the upper side of the top GaAs layer, which has a metallic ground-plane at its underside. The metallic feedline is implemented at the underside of the bottom GaAs layer. Dual wrench-shaped radiators are framed by metallic vias connected to the ground-plane to create SIW cavity. This technique mitigates the surface waves and the substrate losses, thereby improving the antenna’s radiation characteristics. The antenna is excited by a T-shaped feedline implemented on the underside of the bottom GaAs substrate layer. Electromagnetic (EM) energy from the feedline is coupled to the radiating elements through the circular and linear slots etched in the middle ground-plane layer. To mitigate the surface-wave interactions and the substrate losses in the bottom GaAs layer, the feedline is contained inside a SIW cavity. To enhance the antenna’s performance, the radiators are transformed into a metamaterial-inspired surface (i.e., metasurface), by engraving periodic arrangement of circular slots of sub-wavelength diameter and periodicity. Essentially, the slots act as resonant scatterers, which control the EM response of the surface. The antenna of dimensions of 400 × 400 × 8 μm3 is demonstrated to operate over a wide frequency range from 0.445 to 0.470 THz having a bandwidth of 25 GHz with an average return-loss of − 27 dB. The measured average gain and radiation efficiency are 4.6 dBi and 74%, respectively. These results make the proposed antenna suitable for AoC terahertz applications

High performance antenna‑on‑chip inspired by SIW and metasurface technologies for THz band operation

In this paper, a high-performance antenna-on-chip (AoC) is implemented on gallium arsenide (GaAs) wafer based on the substrate integrated waveguide (SIW) and metasurface (MTS) technologies for terahertz band applications. The proposed antenna is constructed using five stacked layers comprising metal-GaAs-metal-GaAs-metal. The conductive electromagnetic radiators are implemented on the upper side of the top GaAs layer, which has a metallic ground-plane at its underside. The metallic feedline is implemented at the underside of the bottom GaAs layer. Dual wrench-shaped radiators are framed by metallic vias connected to the ground-plane to create SIW cavity. This technique mitigates the surface waves and the substrate losses, thereby improving the antenna’s radiation characteristics. The antenna is excited by a T-shaped feedline implemented on the underside of the bottom GaAs substrate layer. Electromagnetic (EM) energy from the feedline is coupled to the radiating elements through the circular and linear slots etched in the middle ground-plane layer. To mitigate the surface wave interactions and the substrate losses in the bottom GaAs layer, the feedline is contained inside a SIW cavity. To enhance the antenna’s performance, the radiators are transformed into a metamaterial inspired surface (i.e., metasurface), by engraving periodic arrangement of circular slots of subwavelength diameter and periodicity. Essentially, the slots act as resonant scatterers, which control the EM response of the surface. The antenna of dimensions of 400 × 400 × 8 μm3 is demonstrated to operate over a wide frequency range from 0.445 to 0.470 THz having a bandwidth of 25 GHz with an average return-loss of − 27 dB. The measured average gain and radiation efficiency are 4.6 dBi and 74%, respectively. These results make the proposed antenna suitable for AoC terahertz applications

A dipole with reflector-backed active metasurface for linear-to-circular polarization reconfigurability

DATA AVAILABILITY STATEMENT : The data presented in this study are on request from the main author.In recent years, significant advances have been made in diversifying the capabilities of communication systems by using reconfigurable antennas. There are many types of reconfigurable antennas—to achieve pattern, frequency, or polarization reconfigurability. These antennas are reconfigured either by the mechanical rotation of surfaces or by enabling or disabling specific sections of the structure using electrical switches. This paper focuses on the concept of a polarization reconfigurable antenna based on an active reflector-backed metasurface. An antenna system based on an active reflector-backed metasurface combined with a planar dipole is designed to achieve reconfigurable polarization. The polarization of the designed antenna can be switched between linear and circular polarization states using positive-intrinsic-negative diodes located in the unit cell elements of the metasurface. The measured results correlate well with the simulated results. The antenna has a physical size of 308 × 162 × 35 mm3 with an impedance bandwidth of 4.5% in the linear state and 7% in the circular state, as well as an axial ratio bandwidth larger than 8.3%.http://www.mdpi.com/journal/materialshj2023Electrical, Electronic and Computer Engineerin

A dipole with active metasurface reflector for polarization reconfigurability

Dissertation (MEng (Electronic Engineering))--University of Pretoria, 2022.In recent years reconfigurable antennas have gained a lot of attention for the advantages they present for diversifying the capabilities of communication systems. Many types of reconfigurable antennas exist that have pattern, frequency, and polarization diversity. These antennas are reconfigured either by mechanical rotating surfaces or by enabling specific sections of a structure with electrical switches. The use of an active reflective metasurface to design an antenna system with reconfigurable polarization was particularly interesting as little research have been done on the topic and presented an interesting concept to expand upon. This study focusses on the concept of a reconfigurable antenna based on an active reflective metasurface with reconfigurable polarization. Subsequently, an antenna system based on an active reflective metasurface combined with a planar dipole is proposed to achieve reconfigurable polarization. The aim of this antenna is achieve reconfigurable polarization through electrical switches positioned on the reflective metasurface. The polarization of the designed antenna can be switched between linear and circular polarization states through the use of positive-intrinsic-negative (PIN) diodes on the reflective metasurface. The designed antenna was manufactured and tested and functioned as expected. The measured results correlated well with the simulated results. The antenna has a physical size of 308 x 162 x 35 mm3 with an impedance bandwidth of 4.5% in the linear state, and 7% in the circular state, as well as an axial ratio bandwidth of 8.3%. This gives the antenna an effective bandwidth of 4.5% in the linear state and 7% in the circular state. The final measured results were degraded due to unexpected interference from the biasing network used to control the PIN diodes. However, even with the interference, the concept of a reconfigurable antenna based on an active reflective metasurface was proven. This research contributed to the field of antenna engineering with the focus on expanding the field of reconfigurable antennas.Electrical, Electronic and Computer EngineeringMEng (Electronic Engineering)Unrestricte

Applications of Antenna Technology in Sensors

During the past few decades, information technologies have been evolving at a tremendous rate, causing profound changes to our world and to our ways of living. Emerging applications have opened u[ new routes and set new trends for antenna sensors. With the advent of the Internet of Things (IoT), the adaptation of antenna technologies for sensor and sensing applications has become more important. Now, the antennas must be reconfigurable, flexible, low profile, and low-cost, for applications from airborne and vehicles, to machine-to-machine, IoT, 5G, etc. This reprint aims to introduce and treat a series of advanced and emerging topics in the field of antenna sensors