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Article List
2025, 23(3):189-196.
DOI: 10.11805/TKYDA2024335
Abstract:
To address the issues of complex structure and high fabrication difficulty associated with compact multi-beam antennas in the terahertz frequency band, a terahertz Luneburg lens antenna and a partial Maxwell Fisheye(PMFE) lens antenna operating in the 355 GHz band are proposed. Both antennas use a periodic metallic bed-of-nails structure to realize a gradient refractive index surface wave lens with a minimum structural dimension of 60 μm. To regulate the beam direction in the non-scanning plane, corrugated rings are loaded on the edges of the surface wave lenses. In addition, the waveguide feeding array and the surface wave lens are designed as one piece to ensure structural integrity. High-precision 3D printing(10 μm precision) combined with magnetron sputtering are employed to realize the metallization of two surface wave lenses and low-cost realization of terahertz antenna prototype. The simulated results show the beam scanning capability of ±60° and ±72° for the Luneburg lens antenna and PMFE lens from 350 GHz to 360 GHz, respectively. The Luneburg lens antenna is verified by prototype fabrication and testing, which demonstrates good impedance matching and multibeam scanning performance from 350 GHz to 360 GHz, with a beam scanning range of ±60°, a gain higher than 16 dBi, and a beam-scanning loss better than 1.2 dB. The agreement between the measured and simulated results demonstrates the feasibility of this scheme and provides a new design idea and technology choice for the realization of terahertz multibeam antenna design.
To address the issues of complex structure and high fabrication difficulty associated with compact multi-beam antennas in the terahertz frequency band, a terahertz Luneburg lens antenna and a partial Maxwell Fisheye(PMFE) lens antenna operating in the 355 GHz band are proposed. Both antennas use a periodic metallic bed-of-nails structure to realize a gradient refractive index surface wave lens with a minimum structural dimension of 60 μm. To regulate the beam direction in the non-scanning plane, corrugated rings are loaded on the edges of the surface wave lenses. In addition, the waveguide feeding array and the surface wave lens are designed as one piece to ensure structural integrity. High-precision 3D printing(10 μm precision) combined with magnetron sputtering are employed to realize the metallization of two surface wave lenses and low-cost realization of terahertz antenna prototype. The simulated results show the beam scanning capability of ±60° and ±72° for the Luneburg lens antenna and PMFE lens from 350 GHz to 360 GHz, respectively. The Luneburg lens antenna is verified by prototype fabrication and testing, which demonstrates good impedance matching and multibeam scanning performance from 350 GHz to 360 GHz, with a beam scanning range of ±60°, a gain higher than 16 dBi, and a beam-scanning loss better than 1.2 dB. The agreement between the measured and simulated results demonstrates the feasibility of this scheme and provides a new design idea and technology choice for the realization of terahertz multibeam antenna design.
2025, 23(3):214-224.
DOI: 10.11805/TKYDA2024523
Abstract:
With the development of 6G networks, in-depth research on the propagation characteristics of terahertz(THz) channels in urban environments is crucial for designing efficient, reliable, and secure communication systems. The impact of different types of building corners (including acute, right, obtuse, and curved angles) on the transmission of THz channels and their physical layer security are systematically investigated through a combination of theoretical analysis, numerical simulation, and experimental measurement. The experiments are conducted by using a THz channel measurement system at three frequencies: 140 GHz, 225 GHz, and 320 GHz. Theoretical analysis is performed by using numerical simulations and knife-edge diffraction models. The research findings reveal the effects of corner structures on the propagation of THz waves, including diffraction and reflection phenomena, as well as the impact of frequency variations on these phenomena. This work provides theoretical guidance for the deployment of THz communication systems in urban environments.
With the development of 6G networks, in-depth research on the propagation characteristics of terahertz(THz) channels in urban environments is crucial for designing efficient, reliable, and secure communication systems. The impact of different types of building corners (including acute, right, obtuse, and curved angles) on the transmission of THz channels and their physical layer security are systematically investigated through a combination of theoretical analysis, numerical simulation, and experimental measurement. The experiments are conducted by using a THz channel measurement system at three frequencies: 140 GHz, 225 GHz, and 320 GHz. Theoretical analysis is performed by using numerical simulations and knife-edge diffraction models. The research findings reveal the effects of corner structures on the propagation of THz waves, including diffraction and reflection phenomena, as well as the impact of frequency variations on these phenomena. This work provides theoretical guidance for the deployment of THz communication systems in urban environments.
2025, 23(3):197-201.
DOI: 10.11805/TKYDA2024337
Abstract:
Facing the growing performance requirements of future mobile network application scenarios, Terahertz(THz) Integrated Sensing and Communication(ISAC) technology, with its advantages of high-speed communication and high-precision sensing, has become a current research hotspot.Existing research has largely focused on the performance analysis, waveform design, and system architecture of THz ISAC, with a lack of studies on the channel propagation characteristics of THz ISAC. To address this, a typical indoor laboratory scenario is selected, and a time-domain measurement system based on pseudo-random sequences is established to measure the indoor THz ISAC channel at 140 GHz band. Channel parameters such as path loss are analyzed based on the measurement data. The analysis results indicate that in the indoor scenario, the abundant scatterers are shared by both the communication and sensing channels. They not only appear in the results of sensing echoes but also contribute to the emergence of potential communication multipath components.
Facing the growing performance requirements of future mobile network application scenarios, Terahertz(THz) Integrated Sensing and Communication(ISAC) technology, with its advantages of high-speed communication and high-precision sensing, has become a current research hotspot.Existing research has largely focused on the performance analysis, waveform design, and system architecture of THz ISAC, with a lack of studies on the channel propagation characteristics of THz ISAC. To address this, a typical indoor laboratory scenario is selected, and a time-domain measurement system based on pseudo-random sequences is established to measure the indoor THz ISAC channel at 140 GHz band. Channel parameters such as path loss are analyzed based on the measurement data. The analysis results indicate that in the indoor scenario, the abundant scatterers are shared by both the communication and sensing channels. They not only appear in the results of sensing echoes but also contribute to the emergence of potential communication multipath components.
2025, 23(3):202-213.
DOI: 10.11805/TKYDA2024406
Abstract:
Multiple Input Multiple Output Synthetic Aperture Radar(MIMO SAR) imaging systems use multiple channels to obtain multi-directional information about humans, which is suitable for human security scenarios. However, in THz MIMO SAR imaging systems, due to the large number of antenna elements, how to balance the accuracy and computational efficiency of the echo signal model becomes a key challenge. A cylindrical synthetic aperture is employed to irradiate the human to obtain the echo signals, and these echo signals are processed by using the Polar Format Algorithm(PFA) to achieve THz 3D human imaging. The computational efficiency and imaging results of two different echo signal models, the Physical Optics(PO) algorithm and the Ray Tracing(RT) method, are compared by simulation for computing a Perfect Electric Conductor(PEC) material-human body. The results show that the PO algorithm using Graphics Processing Unit(GPU) acceleration performs well in terms of computational efficiency and imaging quality, with less than one hour of computation time to compute the entire cylindrical synthetic aperture echo signal, and the imaging results clearly reproduce the shape of the hazardous object. In addition, the PO algorithm also performs well in calculating echo signals that match the actual material of the human body. The effect of directional antennas with different lobe widths on the imaging results is also explored. This provides a more accurate and efficient echo signal model for future validation and optimization of imaging algorithms.
Multiple Input Multiple Output Synthetic Aperture Radar(MIMO SAR) imaging systems use multiple channels to obtain multi-directional information about humans, which is suitable for human security scenarios. However, in THz MIMO SAR imaging systems, due to the large number of antenna elements, how to balance the accuracy and computational efficiency of the echo signal model becomes a key challenge. A cylindrical synthetic aperture is employed to irradiate the human to obtain the echo signals, and these echo signals are processed by using the Polar Format Algorithm(PFA) to achieve THz 3D human imaging. The computational efficiency and imaging results of two different echo signal models, the Physical Optics(PO) algorithm and the Ray Tracing(RT) method, are compared by simulation for computing a Perfect Electric Conductor(PEC) material-human body. The results show that the PO algorithm using Graphics Processing Unit(GPU) acceleration performs well in terms of computational efficiency and imaging quality, with less than one hour of computation time to compute the entire cylindrical synthetic aperture echo signal, and the imaging results clearly reproduce the shape of the hazardous object. In addition, the PO algorithm also performs well in calculating echo signals that match the actual material of the human body. The effect of directional antennas with different lobe widths on the imaging results is also explored. This provides a more accurate and efficient echo signal model for future validation and optimization of imaging algorithms.
2025, 23(3):225-230.
DOI: 10.11805/TKYDA2024531
Abstract:
With the continuous development of 6G technology, terahertz radar and integrated sensing and communication are gradually becoming important research directions in the field of electronics and information. Programmable metasurfaces, with their advantages of being lightweight, conformable, and dynamically tunable,exhibit a high degree of freedom in terahertz beam manipulation, and thus hold significant application potential in communication, imaging, and radar. Starting from the design theory of programmable metasurfaces loaded with semiconductor components, a GaAs varactor suitable for high-frequency applications is selected, a 1 bit digital coding metasurface is constructed, and its sub-terahertz electromagnetic response and beam manipulation performance are characterized. The results show that the metasurface array has wide-angle dynamic beamforming and beam scanning capabilities in the W-band, with experimental results matching well with simulations.
With the continuous development of 6G technology, terahertz radar and integrated sensing and communication are gradually becoming important research directions in the field of electronics and information. Programmable metasurfaces, with their advantages of being lightweight, conformable, and dynamically tunable,exhibit a high degree of freedom in terahertz beam manipulation, and thus hold significant application potential in communication, imaging, and radar. Starting from the design theory of programmable metasurfaces loaded with semiconductor components, a GaAs varactor suitable for high-frequency applications is selected, a 1 bit digital coding metasurface is constructed, and its sub-terahertz electromagnetic response and beam manipulation performance are characterized. The results show that the metasurface array has wide-angle dynamic beamforming and beam scanning capabilities in the W-band, with experimental results matching well with simulations.
