Article
Computer Science, Information Systems
Sarmad Nozad Mahmood, Asnor Juraiza Ishak, Ali Jalal, Tale Saeidi, Suhaidi Shafie, Azura Che Soh, Muhammad Ali Imran, Qammer H. Abbasi
Summary: This paper introduces a miniaturized, dual-polarized, multiple input-multiple output (MIMO) wearable antenna, which uses leaf-shaped and tree-shaped antennas, and improves antenna performance by loading stubs, parasitic spiral, and shorting pins. Through near-field microwave imaging experiments, the antenna's high fidelity and accurate localization in breast imaging were verified.
Article
Computer Science, Hardware & Architecture
Swathiga Guruswamy, Ramya Chinniah, Kesavamurthy Thangavelu
Summary: The proposed Compact Ultra-Wideband Circularly Tapered Vivaldi Antenna with Director (CTVAD) for microwave-based breast tumour detection system shows improved performance with narrow beam width and high gain, significantly enhanced return loss in the frequency band (3.1 GHz-10.6 GHz).
ANALOG INTEGRATED CIRCUITS AND SIGNAL PROCESSING
(2021)
Article
Chemistry, Analytical
Xiaodong Shi, Jiaoyang Li, Saptarshi Mukherjee, Srijan Datta, Vivek Rathod, Xinyu Wang, Wei Lu, Lalita Udpa, Yiming Deng
Summary: This article proposes a method for in situ, non-destructive root phenotyping using ultra-wideband microwave scanning. Through simulation and experiments, the method has been proven capable of accurately measuring and imaging the size and number of roots.
Article
Chemistry, Multidisciplinary
Jianchun Xu, Zhao Li, Xuchao Pan, Xi Wen, Jinqing Cao, Wen Gong, Shaolong Yang, Ming Lei, Fangzhou Yao, Ke Bi
Summary: Mechanical antennas based on piezoelectric materials can significantly reduce the size of long wave antennas and improve communication capacity. However, their narrow bandwidth and weak field intensity limit their practical applications. A mechanical antenna based on PMN-PT is proposed to address these limitations and exhibits ultra-wideband characteristics and excellent communication properties.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Chengwei Zhao, Yanping Bai, Qiang Wei
Summary: This paper presents a novel all-metal Vivaldi antenna design with a simple structure and convenient machining, achieving wide impedance bandwidth, stable gain, and symmetric radiation pattern over the frequency range 2-50 GHz.
AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS
(2022)
Article
Computer Science, Information Systems
Muhammad Abbas Khan, Umair Rafique, Huseyin Serif Savci, Anis Nurashikin Nordin, Saad Hassan Kiani, Syed Muzahir Abbas
Summary: This article presents a design for an ultra-wideband (UWB) fractal antenna for microwave imaging applications. The antenna offers a wide bandwidth and constant radiation characteristics, making it suitable for microwave imaging applications.
Article
Food Science & Technology
Joe Garvin, Feras Abushakra, Zachary Choffin, Bayley Shiver, Yu Gan, Lingyan Kong, Nathan Jeong
Summary: This paper proposes a novel microwave imaging system for detecting the ripeness of watermelon as a proof of concept. The design utilizes a circular array with 10 Coplanar Vivaldi antennas offering wide bandwidth, high gain, and high efficiency. S-parameters between antennas are quickly collected via automated channel switching for fast image generation. Comparisons with sample cross-sections show distinct differences in image characteristics based on watermelon maturity. Sugar concentration of unripe and ripe watermelon is also measured and plotted for further validation of the imaging technique.
CURRENT RESEARCH IN FOOD SCIENCE
(2023)
Article
Computer Science, Information Systems
Farhana Parveen, Parveen Wahid
Summary: This study proposes two miniaturized Vivaldi antennas and presents several techniques for reducing the antenna size. By using half-cut superstrates, low-frequency operation is achieved, and a comparison with other Vivaldi antennas demonstrates the feasibility of achieving desired performance with small dimensions.
Article
Chemistry, Multidisciplinary
Ayman M. Qashlan, Rabah W. Aldhaheri, Khalid H. Alharbi
Summary: In this paper, a compact and flexible Vivaldi antenna is designed and utilized in a microwave breast imaging experiment using a nine-antenna array. By collecting backscattered signals, the image of the breast phantom can be reconstructed to identify and locate tumors accurately, regardless of their size.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Electrical & Electronic
Jingjing Wang, Jianwei Liu, Kangming Hou, Yongcheng Li
Summary: A novel antipodal Vivaldi antenna with enhanced gain and directivity is proposed in this paper. The substrate of the antenna is innovated to a combination of circular-shaped and rectangular-shaped. To enhance the gain, a fan-shaped expansion structure is loaded along the opening of the patch, and several directors are loaded in the vertical direction of the substrate to enhance the directivity. The results show that the proposed antenna has a reflection coefficient below -12 dB in the frequency range of 3 to 10 GHz, and the peak gain is higher than 8 dBi after 6 GHz.
AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS
(2023)
Article
Chemistry, Analytical
Ruiyue Hu, Feng Zhang, Shengbo Ye, Guangyou Fang
Summary: In this paper, an ultra-wideband and high-gain Vivaldi antenna with artificial electromagnetic material is proposed for ground-penetrating radar systems. The antenna utilizes directors loaded inside the antenna gradient slot and an artificial electromagnetic material composed of H-shaped units to improve gain and radiation directivity. Experimental results show that the antenna has good impedance matching and a maximum realized gain of 15.2 dBi.
Article
Computer Science, Information Systems
Mohamad Yafik Ihtisyam Yazid, Mohd Hafiz Baharuddin, Mohammad Shahidul Islam, Mohammad Tariqul Islam, Ali F. Almutairi
Summary: This paper presents the development of an antipodal Vivaldi antenna with a fractal slot, which has potential applications in multisensory systems for head stroke imaging. The fractal slot is utilized to enhance the antenna's directivity, bandwidth, and gain. The research aims to design and optimize a compact Vivaldi antenna with the fractal slot for detecting stroke in the human head. The proposed antenna achieves a wide bandwidth of 1.44 GHz (2.35 GHz to 3.79 GHz) and a maximum gain of 7.35 dBi, and it meets the requirements for microwave imaging procedures.
Review
Chemistry, Analytical
Umair Rafique, Stefano Pisa, Renato Cicchetti, Orlandino Testa, Marta Cavagnaro
Summary: This paper presents a comprehensive review of different ultra-wideband (UWB) antenna designs for near-field microwave imaging, discussing their manufacturing technology, radiative performances, radiation mechanisms, as well as techniques used to reduce the size and improve the bandwidth.
Article
Engineering, Electrical & Electronic
Shaopeng Pan, Wanting Shen, Yang Feng, Zhu Liu, Pei Xiao, Gaosheng Li
Summary: In this study, the operating bandwidth of the Vivaldi antenna was enhanced by designing gradient elliptical slots and integrating an ultra-wideband metasurface lens. The proposed design successfully achieved both a wider bandwidth and improved performance of the antenna, while also achieving miniaturization.
AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS
(2021)
Article
Engineering, Biomedical
Timo Lauteslager, Mathias Tommer, Tor S. Lande, Timothy G. Constandinou
Summary: This study focused on utilizing radar-on-chip technology for dynamic microwave imaging in the body, successfully locating the femoral artery and imaging the beating heart. Through beamforming, cardiac activity was detected in the body, representing the initial steps towards biomedical dynamic microwave imaging.
IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING
(2022)
Article
Chemistry, Analytical
Antonio Lazaro, Marti Boada, Ramon Villarino, David Girbau
Article
Engineering, Electrical & Electronic
Antonio Lazaro, Marti Boada, Ramon Villarino, David Girbau
IEEE SENSORS JOURNAL
(2019)
Article
Engineering, Electrical & Electronic
Antonio Lazaro, Marc Lazaro, Ramon Villarino, Pedro de Paco
Summary: This study proposes a method to improve the detection of pedestrians, workers or cyclists using rotating backscatter with automotive radar, addressing the issue of these elements being masked due to their low radar cross-section. By introducing a different micro-Doppler signature, the detection of these elements is enhanced.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Jordi Verdu, Eloi Guerrero, Josep Parron, Antonio Lazaro, Pedro de Paco
Summary: This study investigates the use of deliberate geometries for rotating targets to improve detectability and classification based on their micro-Doppler signature. Different star-shaped wheels with specific geometries were designed to demonstrate unique modulation waveforms and reflection characteristics. The signatures of these rotating star-shaped wheels were measured in an anechoic chamber using a 24 GHz FMCW radar platform, and a detection algorithm based on the derivative of cross-correlation was proposed to validate the approach.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Benito Gonzalez, Jose M. Cabrera, Antonio Lazaro
Summary: Thermal impedance is essential for describing the thermal behavior in SOI devices. An empirical physical model based on gate length was proposed in this study to calculate the thermal impedance of multi-finger PD SOI MOSFETs. The parameters of the model were obtained from measurements, and it correctly predicted the thermal time constants for various gate lengths.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Chemistry, Analytical
Marc Lazaro, Antonio Lazaro, Ramon Villarino, David Girbau
Summary: The smart mask presented in this paper allows monitoring of body temperature and breathing rate, while communicating through LoRa technology to reduce power consumption. It measures breathing rate by detecting temperature changes within the mask and ensures accuracy akin to traditional methods. Additionally, it can assist in checking the correct placement of the mask and detecting cough episodes.
Article
Engineering, Electrical & Electronic
Benito Gonzalez, Antonio Lazaro, Raul Rodriguez
Summary: This article successfully extracts the thermal resistance of GaN-based high-electron-mobility transistors (HEMTs) on silicon using an ac conductance method. The obtained thermal resistances are comparable to those obtained with pulsed measurements, and the gate geometry dependence of the thermal resistance has been successfully modeled for circuit-design purposes.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Chemistry, Analytical
Antonio Lazaro, Arnau Porcel, Marc Lazaro, Ramon Villarino, David Girbau
Summary: This study investigates the feasibility of introducing false information into a signal received by a FMCW radar using backscatter-modulated tags. A spoofing device was designed and tested, successfully generating a pair of false targets, and countermeasures to detect spoofing attacks were proposed.
Article
Chemistry, Analytical
Antonio Lazaro, Ramon Villarino, Marc Lazaro, Nicolau Canellas, Beatriz Prieto-Simon, David Girbau
Summary: This study investigates the feasibility of using a battery-less NFC potentiostat for the next generation of electrochemical point-of-care sensors, presenting a design based on an NFC microchip and a custom potentiostat. The prototype shows excellent agreement with measurements obtained from a commercial glucometer.
Article
Chemistry, Analytical
Marc Lazaro, Antonio Lazaro, Benito Gonzalez, Ramon Villarino, David Girbau
Summary: This study presents an economical and easy-to-use system for assessing heat transfer in building envelopes. The proposed system aims to reduce measurement time and cost by incorporating a low-cost 3D-printed heat flux sensor, a LoRa transceiver, and two temperature sensors.
Article
Engineering, Electrical & Electronic
Nil Munte, Antonio Lazaro, Ramon Villarino, David Girbau
Summary: This paper introduces a framework of vehicle occupancy detectors based on mm-Wave radar technology. By measuring small movements of the body on the seats, the system can accurately detect whether there are people occupying the seats.
IEEE SENSORS JOURNAL
(2022)
Article
Chemistry, Analytical
Antonio Lazaro, Marc Lazaro, Ramon Villarino, David Girbau
Summary: This paper studies the feasibility of enhancing the detection of vulnerable road users using continuous wave (CW) radars. It proposes a method based on spread spectrum radio communication between these users and automotive radars, which does not require hardware modifications. Experimental results with a scooter using a low-power Doppler radar at a 24 GHz band are provided.
Article
Computer Science, Information Systems
Antonio Lazaro, Marc Lazaro, Ramon Villarino
Summary: This paper introduces a novel room-level localization approach for LoRa backscatter devices, which determines device position by comparing received signal strength and utilizes different machine learning classifiers to enhance system accuracy. In real-life tests, linear discriminant analysis achieved up to 89.7% accuracy.
Article
Chemistry, Analytical
Marc Lazaro, Antonio Lazaro, Ramon Villarino
Article
Computer Science, Information Systems
Marti Boada, Antonio Lazaro, Ramon Villarino, David Girbau
