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Article List
2026, 24(2):107-127.
DOI: 10.11805/TKYDA2025302
Abstract:
The terahertz(THz) frequency band(0.1~10 THz), situated between millimeter waves and infrared light, possesses unique physical characteristics and has become a critical technology in modern communication, imaging, sensing, and security detection. This article summarizes the research progress in terahertz solid-state devices, with a particular focus on the technological development of key circuits such as terahertz solid-state Power Amplifiers(PA), Low-Noise Amplifiers(LNA), frequency multipliers, and mixers. With continuous breakthroughs in materials and processes, terahertz devices have gradually achieved high integration, miniaturization, and low cost, especially with remarkable progress in the application of GaN, InP, and silicon-based technologies. This article also discusses the challenges and future development directions of terahertz solid-state devices, including innovations in material systems, integrated design of devices and circuits, and system optimization.
The terahertz(THz) frequency band(0.1~10 THz), situated between millimeter waves and infrared light, possesses unique physical characteristics and has become a critical technology in modern communication, imaging, sensing, and security detection. This article summarizes the research progress in terahertz solid-state devices, with a particular focus on the technological development of key circuits such as terahertz solid-state Power Amplifiers(PA), Low-Noise Amplifiers(LNA), frequency multipliers, and mixers. With continuous breakthroughs in materials and processes, terahertz devices have gradually achieved high integration, miniaturization, and low cost, especially with remarkable progress in the application of GaN, InP, and silicon-based technologies. This article also discusses the challenges and future development directions of terahertz solid-state devices, including innovations in material systems, integrated design of devices and circuits, and system optimization.
2026, 24(2):128-150.
DOI: 10.11805/TKYDA2025377
Abstract:
Terahertz (THz) antennas feature compact size, wide bandwidth, and strong anti-interference capabilities, serving vital functions in transmitting and receiving THz waves within THz systems. However, the THz frequency band suffers from high free-space path loss, and the gain of single THz antennas is typically limited. Consequently, the development of THz array antenna technology has emerged as one of the core research directions in the THz antenna field. This paper systematically reviews the latest research progress and primary innovative approaches of four mainstream THz array antenna technologies:THz planar array antennas on dielectric substrates, THz packaged array antennas, THz on-chip array antennas, and THz waveguide slot array antennas. It compares the similarities, differences, and respective advantages of various studies, and identifies suitable application scenarios for each type of THz array antenna technology (such as vehicular/airborne communications and radar systems). Finally, it summarizes and prospects the future challenges faced by THz array antenna technology and their potential solutions.
Terahertz (THz) antennas feature compact size, wide bandwidth, and strong anti-interference capabilities, serving vital functions in transmitting and receiving THz waves within THz systems. However, the THz frequency band suffers from high free-space path loss, and the gain of single THz antennas is typically limited. Consequently, the development of THz array antenna technology has emerged as one of the core research directions in the THz antenna field. This paper systematically reviews the latest research progress and primary innovative approaches of four mainstream THz array antenna technologies:THz planar array antennas on dielectric substrates, THz packaged array antennas, THz on-chip array antennas, and THz waveguide slot array antennas. It compares the similarities, differences, and respective advantages of various studies, and identifies suitable application scenarios for each type of THz array antenna technology (such as vehicular/airborne communications and radar systems). Finally, it summarizes and prospects the future challenges faced by THz array antenna technology and their potential solutions.
2026, 24(2):151-165.
DOI: 10.11805/TKYDA2025264
Abstract:
Terahertz(THz) waves, situated between the infrared and microwave bands, possess unique properties such as high transmissivity, low photon energy, coherence, fingerprint spectra, and transient characteristics. Compared with microwaves, X-rays, and other technologies, they have greater advantages in imaging and can compensate for the shortcomings of traditional imaging technologies. With advancements in photonic and microelectronic technologies, terahertz imaging has been widely applied and has achieved significant results in fields such as non-destructive testing, biochemical sensing, and material analysis. This paper systematically reviews the research progress in terahertz(THz) imaging technologies, focusing on raster-scanning imaging, Focal-Plane Array(FPA) imaging, Synthetic Aperture Radar(SAR) imaging, and near-field imaging techniques, while analyzing the resolution, speed, and suitable application scenarios of each technology. It also highlights the critical role of terahertz imaging in materials science, cultural heritage inspection, and biomedical applications, discusses its current limitations, and outlines future development directions.
Terahertz(THz) waves, situated between the infrared and microwave bands, possess unique properties such as high transmissivity, low photon energy, coherence, fingerprint spectra, and transient characteristics. Compared with microwaves, X-rays, and other technologies, they have greater advantages in imaging and can compensate for the shortcomings of traditional imaging technologies. With advancements in photonic and microelectronic technologies, terahertz imaging has been widely applied and has achieved significant results in fields such as non-destructive testing, biochemical sensing, and material analysis. This paper systematically reviews the research progress in terahertz(THz) imaging technologies, focusing on raster-scanning imaging, Focal-Plane Array(FPA) imaging, Synthetic Aperture Radar(SAR) imaging, and near-field imaging techniques, while analyzing the resolution, speed, and suitable application scenarios of each technology. It also highlights the critical role of terahertz imaging in materials science, cultural heritage inspection, and biomedical applications, discusses its current limitations, and outlines future development directions.
2026, 24(2):166-178.
DOI: 10.11805/TKYDA2025297
Abstract:
In the context of global terrorism and violent crime, concealed firearms pose a serious threat to public safety. However, traditional security screening methods suffer from shortcomings such as ineffective non-metal detection, ionizing radiation risks, and low efficiency. Active terahertz imaging technology, with its non-ionizing radiation, strong penetration capability, and high resolution, has emerged as an effective solution for concealed firearm detection. This paper reviews the current status of active terahertz imaging technology in firearm detection. Firstly, it elaborates on the physical characteristics of terahertz waves and the principles of active terahertz imaging, analyzes the technical features of key modules including transmitters, scanning systems, and core algorithms, and categorizes terahertz radar imaging modalities. Secondly, it summarizes research progress in active terahertz imaging for firearm detection both domestically and internationally. Finally, it analyzes technical bottlenecks such as high equipment costs, high-humidity attenuation, undersampling-induced image blurring, insufficient real-time performance in complex environments, and limited portability, while outlining future development directions including multimodal fusion, intelligent algorithm optimization, and standardized system construction. In conclusion, active terahertz imaging has enabled efficient detection of concealed firearms in airports, subways, and other scenarios; future breakthroughs in commercialization will require domestic production of core components and algorithmic innovation.
In the context of global terrorism and violent crime, concealed firearms pose a serious threat to public safety. However, traditional security screening methods suffer from shortcomings such as ineffective non-metal detection, ionizing radiation risks, and low efficiency. Active terahertz imaging technology, with its non-ionizing radiation, strong penetration capability, and high resolution, has emerged as an effective solution for concealed firearm detection. This paper reviews the current status of active terahertz imaging technology in firearm detection. Firstly, it elaborates on the physical characteristics of terahertz waves and the principles of active terahertz imaging, analyzes the technical features of key modules including transmitters, scanning systems, and core algorithms, and categorizes terahertz radar imaging modalities. Secondly, it summarizes research progress in active terahertz imaging for firearm detection both domestically and internationally. Finally, it analyzes technical bottlenecks such as high equipment costs, high-humidity attenuation, undersampling-induced image blurring, insufficient real-time performance in complex environments, and limited portability, while outlining future development directions including multimodal fusion, intelligent algorithm optimization, and standardized system construction. In conclusion, active terahertz imaging has enabled efficient detection of concealed firearms in airports, subways, and other scenarios; future breakthroughs in commercialization will require domestic production of core components and algorithmic innovation.
2026, 24(2):179-184.
DOI: 10.11805/TKYDA2025281
Abstract:
Terahertz radiation imaging enables passive target detection. To accurately obtain terahertz radiation images of targets and the background environment, a terahertz radiation imaging system is designed. The system performs spatial sampling of the field-of-view through two-dimensional scanning, employs a 0.5 m reflector antenna to collect radiation signals into a radiometer with a center frequency of 0.15 THz, and then reconstructs the radiation image of the field-of-view by combining the voltage signal output from the radiometer with spatial sampling parameters. To investigate ground target detectability, visible light, 0.15 THz, and infrared images of the field-of view are measured under day/night and rainy/foggy conditions. Experimental results demonstrate that the 0.15 THz radiation imaging system can capture radiation energy from the cosmic microwave background, enabling accurate detection of high-reflectivity targets during both day and night, as well as in rainy conditions.
Terahertz radiation imaging enables passive target detection. To accurately obtain terahertz radiation images of targets and the background environment, a terahertz radiation imaging system is designed. The system performs spatial sampling of the field-of-view through two-dimensional scanning, employs a 0.5 m reflector antenna to collect radiation signals into a radiometer with a center frequency of 0.15 THz, and then reconstructs the radiation image of the field-of-view by combining the voltage signal output from the radiometer with spatial sampling parameters. To investigate ground target detectability, visible light, 0.15 THz, and infrared images of the field-of view are measured under day/night and rainy/foggy conditions. Experimental results demonstrate that the 0.15 THz radiation imaging system can capture radiation energy from the cosmic microwave background, enabling accurate detection of high-reflectivity targets during both day and night, as well as in rainy conditions.
2026, 24(2):185-195.
DOI: 10.11805/TKYDA2025285
Abstract:
To improve the imaging quality of terahertz Inverse Synthetic Aperture Radar(ISAR) and address the limitations of existing adaptive aperture scaling transform algorithms, this paper proposes a maximum Carrier-to-Noise Ratio(CNR) scaling transform algorithm based on scatterer clustering. The method is founded on the analysis of regional statistical characteristics of the image: image patches are first classified according to background clutter statistics, followed by target scatterer segmentation. Hierarchical Density-Based Spatial Clustering of Applications with Noise(HDBSCAN) is then employed to cluster the scatterers. Finally, an optimization problem is solved to maximize the CNR of target scatterer clusters within each sub-aperture. Experimental results validate the effectiveness of the proposed approach, demonstrating significant CNR improvement in the imaging results, clearer target contours, and enhanced weak scatterers. Compared with existing algorithms, this method innovatively introduces a maximum CNR scaling transform algorithm that segments targets and clusters scatterers to partition scatterer clusters for each sub-aperture. The algorithm maximizes the CNR of the fused image target without altering the energy distribution of scatterers within clusters, thereby enhancing weak scatterer contours while preserving target details, and alleviating the blocking artifacts problem arising from insufficient enhancement of weak scattering regions in conventional methods.
To improve the imaging quality of terahertz Inverse Synthetic Aperture Radar(ISAR) and address the limitations of existing adaptive aperture scaling transform algorithms, this paper proposes a maximum Carrier-to-Noise Ratio(CNR) scaling transform algorithm based on scatterer clustering. The method is founded on the analysis of regional statistical characteristics of the image: image patches are first classified according to background clutter statistics, followed by target scatterer segmentation. Hierarchical Density-Based Spatial Clustering of Applications with Noise(HDBSCAN) is then employed to cluster the scatterers. Finally, an optimization problem is solved to maximize the CNR of target scatterer clusters within each sub-aperture. Experimental results validate the effectiveness of the proposed approach, demonstrating significant CNR improvement in the imaging results, clearer target contours, and enhanced weak scatterers. Compared with existing algorithms, this method innovatively introduces a maximum CNR scaling transform algorithm that segments targets and clusters scatterers to partition scatterer clusters for each sub-aperture. The algorithm maximizes the CNR of the fused image target without altering the energy distribution of scatterers within clusters, thereby enhancing weak scatterer contours while preserving target details, and alleviating the blocking artifacts problem arising from insufficient enhancement of weak scattering regions in conventional methods.
2026, 24(2):196-205.
DOI: 10.11805/TKYDA2025246
Abstract:
Limited by the diffraction limit, the theoretical limit of spatial imaging resolution for far-field terahertz imaging technology is half the wavelength, which fails to meet the testing requirements for the characterization of microscale information in materials. To address the application needs of micro-nano defect detection in new materials such as semiconductor materials and ordered structural materials, this paper designs a wide-bandwidth frequency-swept continuous-wave terahertz near-field imaging system. The system adopts an all-electronic integrated terahertz transceiver module, and through terahertz beam spatial synthesis, it achieves seamless coverage of the test frequency range from 0.11 to 1.10 THz with a frequency resolution of 1 Hz. Via multi-frequency point information fusion, micro-nano defect detection and identification in materials are realized, with a spatial imaging resolution of ≤100 nm, the imaging field of view reaches 100 μm×100 μm. Tests and characterizations on semiconductor materials and ordered structural materials verify that the system in this paper can obtain high-quality near-field images by selecting terahertz frequency points at which the test materials exhibit strong responses to the high-resolution frequency-swept continuous wave.
Limited by the diffraction limit, the theoretical limit of spatial imaging resolution for far-field terahertz imaging technology is half the wavelength, which fails to meet the testing requirements for the characterization of microscale information in materials. To address the application needs of micro-nano defect detection in new materials such as semiconductor materials and ordered structural materials, this paper designs a wide-bandwidth frequency-swept continuous-wave terahertz near-field imaging system. The system adopts an all-electronic integrated terahertz transceiver module, and through terahertz beam spatial synthesis, it achieves seamless coverage of the test frequency range from 0.11 to 1.10 THz with a frequency resolution of 1 Hz. Via multi-frequency point information fusion, micro-nano defect detection and identification in materials are realized, with a spatial imaging resolution of ≤100 nm, the imaging field of view reaches 100 μm×100 μm. Tests and characterizations on semiconductor materials and ordered structural materials verify that the system in this paper can obtain high-quality near-field images by selecting terahertz frequency points at which the test materials exhibit strong responses to the high-resolution frequency-swept continuous wave.
2026, 24(2):206-212.
DOI: 10.11805/TKYDA2025306
Abstract:
Terahertz radar, with its high-resolution imaging capability, renders shadows in Synthetic Aperture Radar(SAR) images with high clarity and rich detail, offering a new dimension for target structure inference. This paper systematically explores the shadow characteristics of terahertz radar and their application value in structure inversion. Through imaging experiments on typical targets such as tall towers, moving tanks, trees, and sundials, three major advantages are validated: shadow imaging effectively eliminates the layover effect in tall buildings, providing unambiguous geometric contours; shadows of moving targets present stable, optically similar outlines, offering a new approach for judging the structure of moving objects; and shadows reliably reveal extended fine structures such as tank barrels and gnomon. The research demonstrates that the shadow characteristics of terahertz radar can effectively compensate for the shortcomings of traditional scattering intensity-based methods, providing a highly reliable technical approach for target structure inference.
Terahertz radar, with its high-resolution imaging capability, renders shadows in Synthetic Aperture Radar(SAR) images with high clarity and rich detail, offering a new dimension for target structure inference. This paper systematically explores the shadow characteristics of terahertz radar and their application value in structure inversion. Through imaging experiments on typical targets such as tall towers, moving tanks, trees, and sundials, three major advantages are validated: shadow imaging effectively eliminates the layover effect in tall buildings, providing unambiguous geometric contours; shadows of moving targets present stable, optically similar outlines, offering a new approach for judging the structure of moving objects; and shadows reliably reveal extended fine structures such as tank barrels and gnomon. The research demonstrates that the shadow characteristics of terahertz radar can effectively compensate for the shortcomings of traditional scattering intensity-based methods, providing a highly reliable technical approach for target structure inference.
2026, 24(2):213-226.
DOI: 10.11805/TKYDA2025323
Abstract:
Behavior analysis and cognition of space targets are crucial for the in-orbit safety maintenance and status monitoring of space assets. Terahertz(THz) radar, with its short wavelength, large bandwidth, and significant Doppler effect, offers unique advantages in the inversion and identification of anomalies in space targets. Previous studies primarily focuses on known full-process anomalies, while studies on unknown behaviors, particularly those involving the moment of anomaly occurrence, remain limited. This paper first establishes an anomaly model for typical space objects and simulates their echoes. Subsequently, a multidimensional feature analysis framework integrating time-domain signals, one-dimensional range images, micro-Doppler data, and two-dimensional imaging is constructed. The effectiveness of this method is validated using actual measurement data. Results indicate that phase discontinuities indicate the onset of anomaly events; shifts and distortions in the one-dimensional range image correlate with orbital anomalies; micro-Doppler features and local distortions in the two-dimensional image are closely associated with attitude and shape anomalies. Signal characteristics derived from terahertz radar enable precise localization of anomaly onset and classification of anomaly types, providing a systematic technical approach for real-time recognition of space object anomaly behavior.
Behavior analysis and cognition of space targets are crucial for the in-orbit safety maintenance and status monitoring of space assets. Terahertz(THz) radar, with its short wavelength, large bandwidth, and significant Doppler effect, offers unique advantages in the inversion and identification of anomalies in space targets. Previous studies primarily focuses on known full-process anomalies, while studies on unknown behaviors, particularly those involving the moment of anomaly occurrence, remain limited. This paper first establishes an anomaly model for typical space objects and simulates their echoes. Subsequently, a multidimensional feature analysis framework integrating time-domain signals, one-dimensional range images, micro-Doppler data, and two-dimensional imaging is constructed. The effectiveness of this method is validated using actual measurement data. Results indicate that phase discontinuities indicate the onset of anomaly events; shifts and distortions in the one-dimensional range image correlate with orbital anomalies; micro-Doppler features and local distortions in the two-dimensional image are closely associated with attitude and shape anomalies. Signal characteristics derived from terahertz radar enable precise localization of anomaly onset and classification of anomaly types, providing a systematic technical approach for real-time recognition of space object anomaly behavior.
2026, 24(2):227-235.
DOI: 10.11805/TKYDA2025312
Abstract:
In response to the limitations of the radiation source power and the difficulty in controlling the measurement beam in high-frequency terahertz Radar Cross Section(RCS) measurements, a large-quiet-zone RCS measurement system based on the ultra-widely tunable high-power terahertz parametric source and quasi-optical reflective beam expansion is demonstrated. The system can achieve high-sampling-rate, high-sensitivity and high-frequency terahertz RCS measurements. A two-stage terahertz beam expansion and collimation optical path based on off-axis parabolic mirrors is designed by using Zemax software, which can uniformly expand terahertz beams at different frequencies to over 100 mm. Using the smooth aluminum spheres as the standard calibration targets, the reliability of the measurement system is verified at 3.2 THz and 5.7 THz. On this basis, RCS measurements of smooth aluminum plates, aluminum columns and missile models are completed, and the variation trends with terahertz frequencies are discussed. The measurement results show that the dynamic range of the measurement system can reach up to 68 dB, and the measurement accuracy is better than 3 dBsm. The RCS measurement system and measurement results can support the design of high-frequency terahertz radar systems and the scale-model measurements of large-sized targets.
In response to the limitations of the radiation source power and the difficulty in controlling the measurement beam in high-frequency terahertz Radar Cross Section(RCS) measurements, a large-quiet-zone RCS measurement system based on the ultra-widely tunable high-power terahertz parametric source and quasi-optical reflective beam expansion is demonstrated. The system can achieve high-sampling-rate, high-sensitivity and high-frequency terahertz RCS measurements. A two-stage terahertz beam expansion and collimation optical path based on off-axis parabolic mirrors is designed by using Zemax software, which can uniformly expand terahertz beams at different frequencies to over 100 mm. Using the smooth aluminum spheres as the standard calibration targets, the reliability of the measurement system is verified at 3.2 THz and 5.7 THz. On this basis, RCS measurements of smooth aluminum plates, aluminum columns and missile models are completed, and the variation trends with terahertz frequencies are discussed. The measurement results show that the dynamic range of the measurement system can reach up to 68 dB, and the measurement accuracy is better than 3 dBsm. The RCS measurement system and measurement results can support the design of high-frequency terahertz radar systems and the scale-model measurements of large-sized targets.
11 Analysis of Radar Cross Sections for aluminum targets in terahertz band at different temperatures
2026, 24(2):236-241.
DOI: 10.11805/TKYDA2025345
Abstract:
The temperature-dependent variation of metal material reflectivity in the terahertz band is of great significance for research on active-passive fusion detection of terahertz targets. This paper focuses on metallic aluminum, and by comparing with literature and measured results, verifies that the extended Hagen-Rubens theoretical formula is applicable for studying the reflection performance of metals in the terahertz band. Five typical terahertz frequency points of 0.1, 0.2, 0.5, 1.0 and 10 THz are selected to calculate the reflectivity of metallic aluminum within the temperature range of 273~933 K. It is found that as temperature increases, the reflectivity of metallic aluminum in the terahertz band gradually decreases, with the reflectivity variation not exceeding 0.02. The temperature-dependent variation of terahertz Radar Cross Section(RCS) is analyzed for typical metallic aluminum spheres, square aluminum thin plates, and cylinders at different temperatures. The results indicate that the target RCS slowly decreases within the 273~933 K range, with the variation not exceeding 0.05 dB.
The temperature-dependent variation of metal material reflectivity in the terahertz band is of great significance for research on active-passive fusion detection of terahertz targets. This paper focuses on metallic aluminum, and by comparing with literature and measured results, verifies that the extended Hagen-Rubens theoretical formula is applicable for studying the reflection performance of metals in the terahertz band. Five typical terahertz frequency points of 0.1, 0.2, 0.5, 1.0 and 10 THz are selected to calculate the reflectivity of metallic aluminum within the temperature range of 273~933 K. It is found that as temperature increases, the reflectivity of metallic aluminum in the terahertz band gradually decreases, with the reflectivity variation not exceeding 0.02. The temperature-dependent variation of terahertz Radar Cross Section(RCS) is analyzed for typical metallic aluminum spheres, square aluminum thin plates, and cylinders at different temperatures. The results indicate that the target RCS slowly decreases within the 273~933 K range, with the variation not exceeding 0.05 dB.
2026, 24(2):242-250.
DOI: 10.11805/TKYDA2025261
Abstract:
Parabolic antennas enable long-distance, high-precision signal transmission and reception, making them widely used in the field of communications. In recent years, parabolic antennas have gained significant attention in space situational awareness applications due to advances in extraction techniques for geometric parameters(such as antenna pointing direction) from Inverse Synthetic Aperture Radar(ISAR) images. However, accurately and efficiently estimating the attitude of parabolic antennas remains a major challenge. Addressing the insufficient extraction of parabolic characteristics in current approaches, this paper proposes ISARAngleNet, a network that integrates scattering point enhancement with Transformer architecture. The method incorporates specialized scattering point enhancement modules within ResNet(Residual Network) residual blocks to extract robust antenna features, while introducing a Transformer model to overcome ResNet's limitations in global feature modeling. Additionally, we develop a loss function that combines dual-path attitude regression with scattering point smoothness constraints, enabling the network to better capture complex relationships between angular and scattering features. The anechoic chamber experiments demonstrate that, compared to the standard ResNet network, the proposed method achieves improvements of 32.85% and 24.5% in RMSE(Root Mean Square Error) and MAE(Mean Absolute Error), respectively, on the parabolic antenna datasets, thereby validating its superiority.
Parabolic antennas enable long-distance, high-precision signal transmission and reception, making them widely used in the field of communications. In recent years, parabolic antennas have gained significant attention in space situational awareness applications due to advances in extraction techniques for geometric parameters(such as antenna pointing direction) from Inverse Synthetic Aperture Radar(ISAR) images. However, accurately and efficiently estimating the attitude of parabolic antennas remains a major challenge. Addressing the insufficient extraction of parabolic characteristics in current approaches, this paper proposes ISARAngleNet, a network that integrates scattering point enhancement with Transformer architecture. The method incorporates specialized scattering point enhancement modules within ResNet(Residual Network) residual blocks to extract robust antenna features, while introducing a Transformer model to overcome ResNet's limitations in global feature modeling. Additionally, we develop a loss function that combines dual-path attitude regression with scattering point smoothness constraints, enabling the network to better capture complex relationships between angular and scattering features. The anechoic chamber experiments demonstrate that, compared to the standard ResNet network, the proposed method achieves improvements of 32.85% and 24.5% in RMSE(Root Mean Square Error) and MAE(Mean Absolute Error), respectively, on the parabolic antenna datasets, thereby validating its superiority.
2026, 24(2):251-257.
DOI: 10.11805/TKYTDA2025197
Abstract:
Based on a spintronic terahertz source employing a heterostructure of ferromagnetic metal Ni80Fe20 and non-magneticmetal Pt, the amplitude of terahertz waves can be modulated by applying currents with different current densities. The spintronic terahertz source is connected to a Printed Circuit Board(PCB) via wire bonding. By applying various magnitudes of current through a current source, the electromagnetic signals radiated from the spintronic terahertz source are collected within a Terahertz Time-Domain Spectroscopy(THz-TDS) system. Since current application generates Joule heating in the spintronic terahertz source, heat accumulation leads to temperature rise, which reduces the saturation magnetization of the ferromagnetic material. The terahertz amplitude, influenced by the saturation magnetization of the ferromagnetic layer, decreases with increasing applied current, thereby achieving both signal generation and electrical modulation of the spintronic terahertz source. A modulation depth of approximately 59% is realized across the frequency range of 0.1~2.8 THz. Theoretical derivation reveals that the terahertz emission amplitude is linearly proportional to the cube of the applied current density, which is confirmed by curve fitting of experimental data. This electrical modulation method facilitates the integrated development of spintronic terahertz sources, enriches existing control approaches, and provides a novel pathway for understanding the operational mechanism of spintronic terahertz sources.
Based on a spintronic terahertz source employing a heterostructure of ferromagnetic metal Ni80Fe20 and non-magneticmetal Pt, the amplitude of terahertz waves can be modulated by applying currents with different current densities. The spintronic terahertz source is connected to a Printed Circuit Board(PCB) via wire bonding. By applying various magnitudes of current through a current source, the electromagnetic signals radiated from the spintronic terahertz source are collected within a Terahertz Time-Domain Spectroscopy(THz-TDS) system. Since current application generates Joule heating in the spintronic terahertz source, heat accumulation leads to temperature rise, which reduces the saturation magnetization of the ferromagnetic material. The terahertz amplitude, influenced by the saturation magnetization of the ferromagnetic layer, decreases with increasing applied current, thereby achieving both signal generation and electrical modulation of the spintronic terahertz source. A modulation depth of approximately 59% is realized across the frequency range of 0.1~2.8 THz. Theoretical derivation reveals that the terahertz emission amplitude is linearly proportional to the cube of the applied current density, which is confirmed by curve fitting of experimental data. This electrical modulation method facilitates the integrated development of spintronic terahertz sources, enriches existing control approaches, and provides a novel pathway for understanding the operational mechanism of spintronic terahertz sources.
2026, 24(2):258-263.
DOI: 10.11805/TKYDA2025193
Abstract:
Terahertz chip packaging systems impose stringent requirements on waveguide cavities in terms of miniaturization, high performance, and precision manufacturing. These demands pose significant challenges for the circuit design of the packaging cavity. Traditional design methods rely on manual modeling and parameter tuning, which are time-consuming and inefficient, and struggle to meet the needs of complex structures and multi-objective optimization. This paper proposes an efficient intelligent algorithm based on scripting interfaces of electromagnetic simulation software. The framework enables rapid modeling, performance simulation, and automated optimization of terahertz waveguide cavities. The effectiveness and feasibility of the proposed method are demonstrated through the design and optimization of a Y-band power amplifier cavity. The approach enables efficient and intelligent design of complex waveguide cavities for terahertz chip packaging and holds great promise for applications in high-speed communications, radar systems, and advanced packaging technologies.
Terahertz chip packaging systems impose stringent requirements on waveguide cavities in terms of miniaturization, high performance, and precision manufacturing. These demands pose significant challenges for the circuit design of the packaging cavity. Traditional design methods rely on manual modeling and parameter tuning, which are time-consuming and inefficient, and struggle to meet the needs of complex structures and multi-objective optimization. This paper proposes an efficient intelligent algorithm based on scripting interfaces of electromagnetic simulation software. The framework enables rapid modeling, performance simulation, and automated optimization of terahertz waveguide cavities. The effectiveness and feasibility of the proposed method are demonstrated through the design and optimization of a Y-band power amplifier cavity. The approach enables efficient and intelligent design of complex waveguide cavities for terahertz chip packaging and holds great promise for applications in high-speed communications, radar systems, and advanced packaging technologies.
