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This research article presents, a design of a graphene-based, octagonal shaped three element series feed terahertz (THz) linear array antenna is designed for very short-distance wireless communication applications. The antenna utilizes a four-layer structure comprising a gold ground plate and patch, with quartz (SiO4) serving as the substrate with a thickness of 140 µm deposited on the gold ground plate. On this substrate, an octagonal three-element linear array patch made of gold is applied, and finally, a fourth layer of elliptical-shaped graphene, with a thickness of 10 nm, is deposited onto the gold patch plate. The THz linear array antenna demonstrates good performance, with a reflection coefficient value of less than − 10 dB in the 0.285–0.535 THz range, resulting in a substantial 250 GHz bandwidth and the peak realized gain value is 5.25 dBi. Further, the designed antenna employs material switching via change in the chemical potential of graphene to attain pattern reconfigurability and facilitates beam steering capabilities for wireless applications. [ABSTRACT FROM AUTHOR]

This research paper presents, an octagonal shaped graphene based terahertz patch antenna is designed for indoor communications. For a unit cell, a single graphene layer with a thickness of 10 nm has been layered over a quartz (SiO4) substrate with a thickness of 100 µm to increase the effectiveness of the multiple-input and multiple-output (MIMO) antenna. The MIMO antenna is chosen to operate at a frequency of 0.3 THz. For a quad-port MIMO configuration, the element cells have been arranged orthogonally. The total cross-sectional area of the terahertz (THz) MIMO antenna is 1325 × 1325 µm2. The suggested MIMO antenna device achieves a bandwidth of 113 GHz over a frequency range of 0.257–0.370 THz. Moreover, the mutual coupling coefficient is less than − 15 dB. The designed THz MIMO antenna's diversity performance is analyzed and the obtained diversity matrices are the diversity gain (DG) (< 9.96 dB), envelope correlation coefficient (ECC) (< 0.01), channel capacity loss (CCL) (< 0.35 bps/Hz), and total active reflection coefficient (TARC) (< − 10 dB), respectively. [ABSTRACT FROM AUTHOR]

The recent resurgence of new-generation reconfigurable technologies delivers a plethora of various applications in all public, private and enterprise solutions over the globe. In this paper, a frequency reconfigurable polarization and pattern diverse Multiple-Input-Multiple-Output (MIMO) antenna is presented for indoor scenarios. The MIMO antenna is comprised of twelve radiating elements, and polarization and pattern diversity is obtained by arranging them in three different planes: Horizontal Plane (HP), Vertical Plane-I (VP-I), and Vertical Plane-II (VP-II). The proposed antenna operates in mode I (wideband) and mode II (multiband), by combining two different radiators using PIN diodes. The antenna dynamically switches between Mode I (wideband) and mode II (multiband). Mode, I cover the ultra-wideband (UWB) range from 2.3 to 12 GHz, while mode II covers GSM (1.85–1.9 GHz), Wi-Fi and LTE-7 (2.419–2.96 GHz), 5G (3.15–3.28 GHz and 3.45–3.57 GHz), public safety WLAN (4.817–4.94 GHz), and WLAN (5.11–5.4 GHz) frequency bands. The peak gain and efficiency of the MIMO antenna are 5.2 dBi and 80%, respectively. [ABSTRACT FROM AUTHOR]

Terahertz generation through photoconductive antenna (PCA) is quite popular mainly due to the advancement of nanotechnology and material research. An extensive investigation of the interdigitated photoconductive antenna (IPCA) in the terahertz (THz) frequency band has been carried out based on numerical modeling. An equivalent circuit model for IPCA based on its electrical perspective with corresponding expressions has been solved to understand the capacitive behavior of the gap between the interdigitated electrodes. This work explores the performance of IPCA with variation in structural parameters of their interdigitated electrode geometry in the active region. The interdigitated elemental periodicity, width and length of the IPCA are varied by keeping the interdigitated gap constant between the elements. The temporal behavior of generated electric field and its corresponding spectral response of the IPCAs with variation in the interdigitated electrode geometry has been compared. Moreover, the coupling behavior of the elements has been observed in the generated radiation. Finally, the results prove that the THz amplitude, frequency and efficiency can be enhanced by optimizing the structural parameters of the interdigitated electrode elements in the active region. This analysis is very useful while doing the practical experiments in spectroscopy, imaging and communication applications. [ABSTRACT FROM AUTHOR]

Terahertz generation through a photoconductive antenna is quite popular, mainly due to the advancement of nanotechnology and material research. Based on numerical modelling, a thorough study of the interdigitated photoconductive antenna (IPCA) in the terahertz (THz) frequency region has been conducted. To comprehend the capacitive behaviour of the gap between the interdigitated electrodes, an equivalent circuit model for IPCA based on its electrical perspective with matching expressions has been solved. This work explores the performance of IPCA with variations in structural parameters of their interdigitated electrode geometry in the active region. The interdigitated elemental periodicity, width and length of the IPCA are varied by keeping the interdigitated gap constant between the elements. The temporal behavior of the generated electric field and its corresponding spectral response of the IPCAs with variations in the interdigitated electrode geometry have been compared. Moreover, the coupling behavior of the elements has been observed in the generated radiation. Finally, the results prove that the THz amplitude, frequency and efficiency can be enhanced by optimizing the structural parameters of the interdigitated electrode elements in the active region. This analysis is very useful when doing practical experiments in spectroscopy, imaging and communication applications. [ABSTRACT FROM AUTHOR]