Article
Engineering, Electrical & Electronic
Tingxu Hu, Mo Huang, Yan Lu, Xiu Yin Zhang, Franco Maloberti, Rui Martins
Summary: This article presents a 2.4-GHz differential class-DE synchronous rectifier with near-optimum ZVS, ZCS, and impedance matching achieved through a differential topology. An adaptive bias circuit is used to adjust gate bias voltages with input power for ZVS/ZCS operation within a wide power range. The chip fabricated in a 65-nm CMOS process achieves peak power conversion efficiency of 68.5% at 9-dBm input power with 250-ohm load resistance, with a measured input power range of 16 dB when PCE > 40%.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Shan Gao, Le Chang, Anxue Zhang, Yue Li, Zhijun Zhang
Summary: This article addresses the issue of exact coverage problem of unbalanced Wi-Fi 6 bands by engineering the TM0.5,0 and TM0.5,1 modes of the half-mode patch while maintaining small volume. The design guideline includes selecting proper patch size, optimizing feeding positions, and using lumped components. The proposed half-mode patch with the smallest volume among reported Wi-Fi 6 dual-band patch antennas fully covers the Wi-Fi 6 bands and suits the optimal Wi-Fi 6 RF front-end architecture.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Nanoscience & Nanotechnology
Qi Hu, Ke Chen, Yilin Zheng, Zhiyuan Xu, Jianmin Zhao, Jian Wang, Yijun Feng
Summary: Reconfigurable metasurfaces have emerged as a promising alternative to conventional wireless communication systems. However, most of them are limited to narrow bandwidth. In this paper, a broadband metasurface-based wireless communication system is proposed to adapt to multiple users through joint modulation of digital signals in the time and space domains. Experiments show that the system can provide stable wireless communication service within a broad band and successfully recover transmitted color pictures at user terminals. The proposed system has potential applications in next-generation communications and radar systems.
Article
Engineering, Electrical & Electronic
Hansraj Bhamra, Yu-Wen Huang, Quan Yuan, Pedro Irazoqui
Summary: The article presents a 2.4GHz ultra-low power energy-harvested narrowband transmitter for wireless sensing and biomedical devices. It features high power transfer efficiency and biocompatibility, supporting different data modes of transmission.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2021)
Article
Chemistry, Multidisciplinary
Suthasinee Lamultree, Wutthipong Thanamalapong, Sitthichai Dentri, Chuwong Phongcharoenpanich
Summary: A compact, lightweight, and low-profile tri-band antenna is proposed for WLAN and Ku-band applications, offering excellent performance and supporting wireless communication for self-navigated vehicles.
APPLIED SCIENCES-BASEL
(2022)
Article
Crystallography
Z. Viskadourakis, E. Tamiolakis, O. Tsilipakos, A. C. Tasolamprou, E. N. Economou, G. Kenanakis
Summary: This paper investigates the capability of three-dimensional printed cut-wire metasurfaces to harvest energy in frequencies around 2.4 GHz. The experimental results demonstrate that these metasurfaces exhibit good energy harvesting behavior in the mentioned frequency band.
Article
Chemistry, Multidisciplinary
Yilin Zheng, Ke Chen, Zhiyuan Xu, Na Zhang, Jian Wang, Junming Zhao, Yijun Feng
Summary: This article introduces a dual-band metasurface-assisted wireless communication scheme that enhances information security by providing additional physical channels for transmission. Experimental results confirm that the transmitted picture can be successfully retrieved by synthesizing received signals.
Article
Engineering, Electrical & Electronic
Weiquan Zhang, Yue Li, Kunpeng Wei, Zhijun Zhang
Summary: This article presents a compact multiple-input-multiple-output (MIMO) microstrip antenna system that covers the 2.4 and 5 GHz wireless local area network (WLAN) bands. The dual-band characteristics are achieved by exciting the TM01 and TM03 modes of a microstrip antenna, using a rectangular slot to improve the radiation capability of the TM03 mode, and utilizing two probes to tune the resonant frequency of the TM01 mode. High interport isolation at the two WLAN bands is achieved through isolation enhancement at the lower and upper-frequency bands, introducing split loops to reduce mutual coupling at the 2.4 GHz band, and adding dipole elements in the rectangular slot for high isolation at the 5 GHz band. The proposed antenna system operates at 2.25-2.63 and at 5.14-6.06 GHz, with measured maximum mutual coupling of less than -15.3 dB at both operating frequency bands.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Chemistry, Analytical
Christopher Walsh, Saad G. Muttlak, Mohammadreza Sadeghi, Mohamed Missous
Summary: This work introduces a fully integrated miniature rectenna design that utilizes the unique ASPAT tunnel diode. The ASPAT provides temperature independence, zero bias, and high dynamic range for the rectifier. By integrating the antenna and rectifier on a single chip, impedance matching is achieved, eliminating the need for a matching network and saving space on the GaAs substrate. The miniaturization enabled by the GaAs material allows for economical fabrication and potential applications in medical implants. The design features a die size of 4 x 1.2 mm², achieving a maximum measured output voltage of 0.97 V and successful transmission of a 20 dBm single-tone 2.35 GHz signal at a distance of 5 cm from the rectenna.
Article
Engineering, Electrical & Electronic
Dongmin Kim, Dongmyeong Kim, Ignacio Llamas-Garro, Donggu Im
Summary: A sub-GHz/2.4 GHz highly selective reconfigurable RF front-end with a complementary balun-LNA and a linearized RF-to-BB current-reuse mixer is proposed for internet-of-things (IoT) devices. It achieves short and long-range wireless connectivity and improves gain, noise figure, and linearity with low power consumption.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS
(2023)
Article
Engineering, Electrical & Electronic
Guo-Ping Gao, Ben-Kai Zhang, Jing-Hang Dong, Zhi-Heng Dou, Zhuo-Qi Yu, Bin Hu
Summary: A novel reconfigurable antenna that operates in both ON- and OFF-body modes is proposed in this study. The antenna achieves omnidirectional and unidirectional radiation by using the TM00 and TM10 mode of a rectangular patch. By cutting a rectangular slot on the patch, the resonance frequency of the unidirectional mode is shifted to a lower frequency, resulting in a smaller antenna size and overlapping impedance bandwidths. Four p-i-n diodes are used for arbitrary switching of the operating mode. The measured results show that the antenna covers the 2.4-GHz ISM band with an overlapped bandwidth of 3.8%, and it maintains stable performance when placed on different parts of the human body. The calculated specific absorption rate (SAR) values meet the standards of the United States and Europe, making the proposed antenna suitable for wearable systems.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Materials Science, Multidisciplinary
Yilin Zheng, Zhiyuan Xu, Na Zhang, Jian Wang, Tian Jiang, Ke Chen, Yijun Feng
Summary: With the rapid development of electromagnetic wave manipulation technique, programmable metasurfaces have emerged as a new type of wireless communication transmitter, offering the advantages of simple architecture and low cost. This study proposes a design strategy for a dual-band wireless communication system based on a spatial-division-assisted multi-level amplitude-programmable metasurface. The system allows for independent design of carrier frequency and modulation scheme for each physical channel, achieved by adjusting external bias voltages and applying spatial-coding sequences onto the metasurface. Experimental results demonstrate the feasibility of the system in the sub 6G communication band, successfully transmitting two pictures using different modulation schemes.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Computer Science, Information Systems
Junyang Shi, Xingjian Chen, Mo Sha
Summary: IEEE 802.15.4-based wireless sensor-actuator networks play a significant role in improving industrial efficiency, but managing large and complex networks is difficult. This article presents a solution for enabling cross-technology communication from LoRa to ZigBee, providing reliable communication with high throughput and low bit error rate.
ACM TRANSACTIONS ON SENSOR NETWORKS
(2022)
Article
Engineering, Electrical & Electronic
Guolong Shi, Xinyi Shen, Yigang He, Huan Ren
Summary: In this study, a passive wireless sensor for NH3 detection based on carbon nanotube-loaded chipless radio frequency identification (CRFID) was proposed, which has the advantages of low cost, passive wireless ability, miniaturization, universality, and long life. The HFSS simulation and fabrication for RFID-inspired sensors based on metal ink material printing operating at the central frequency of 2.4 GHz were conducted. The resistance value changes when the NH3 concentration is 0-200 mg/L, showing a negative growth coefficient after absorbing NH3. The experimental results provide a reliable basis for passive wireless NH3 detection and are of great significance for environmental quality assessment and food safety traceability information disclosure.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Computer Science, Information Systems
Xizhou Deng, Ping Yang, Shengtao Chen, Wang Ren
Summary: This paper introduces a novel dual-band circularly polarized rectifier antenna for collecting environmental electromagnetic energy at 2.4 and 5.8 GHz. The antenna achieves circular polarization in these two frequency bands and exhibits wide impedance bandwidths. It also has high gains and can potentially self-power low-power devices in the Internet of Things.
Article
Chemistry, Multidisciplinary
Hiroki Wakatsuchi, Jiang Long, Daniel F. Sievenpiper
ADVANCED FUNCTIONAL MATERIALS
(2019)
Article
Engineering, Electrical & Electronic
H. Wakatsuchi
ELECTRONICS LETTERS
(2019)
Article
Physics, Applied
Kosei Asano, Tomoyuki Nakasha, Hiroki Wakatsuchi
APPLIED PHYSICS LETTERS
(2020)
Article
Multidisciplinary Sciences
Ryoya Aihara, Hiroki Wakatsuchi
SCIENTIFIC REPORTS
(2020)
Article
Multidisciplinary Sciences
Mizuki Tanikawa, Daiju Ushikoshi, Kosei Asano, Kenichiro Sanji, Masakazu Ikeda, Daisuke Anzai, Hiroki Wakatsuchi
SCIENTIFIC REPORTS
(2020)
Article
Multidisciplinary Sciences
Tomoyuki Nakasha, Sendy Phang, Hiroki Wakatsuchi
Summary: Linear metasurfaces have been shown to exhibit waveform-selective responses, while nonlinear metasurfaces offer more flexibility in addressing electromagnetic challenges involving waves at the same frequency. The waveform-selective responses in linear structures are derived from dispersion behaviors, referred to as pseudo-waveform-selective metasurfaces.
ADVANCED THEORY AND SIMULATIONS
(2021)
Article
Nanoscience & Nanotechnology
Haruki Homma, Muhammad Rizwan Akram, Ashif Aminulloh Fathnan, Jiyeon Lee, Christos Christopoulos, Hiroki Wakatsuchi
Summary: By embedding controllable transient circuits, tunable anisotropic impedance surfaces can be achieved to control surface wave propagation based on the incident waveform.
Article
Physics, Applied
Ashif Aminulloh Fathnan, Haruki Homma, Shinya Sugiura, Hiroki Wakatsuchi
Summary: By modeling a metasurface as time-varying admittance sheets, an analytical calculation method is provided to predict the metasurface time-domain responses, allowing the derivation of design specifications in the form of equivalent sheet admittance. Using this method, a waveform-selective Fresnel zone plate with variable focal length depending on the incoming pulse width is synthesized. The proposed synthesis method can be extended to design metasurfaces with more complex spatiotemporal wave manipulation, benefiting applications such as sensing, wireless communications, and signal processing.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Masaya Tashiro, Ashif Aminulloh Fathnan, Yuta Sugiura, Akira Uchiyama, Hiroki Wakatsuchi
Summary: The authors present metasurface-inspired maintenance-free IoT tags that can be characterized by both frequency-domain and time-domain profiles. The waveform-selective mechanisms of circuit-based metasurfaces allow the tags to behave differently at the same frequency based on the pulse duration of the incident wave. The proposed designs are validated numerically and experimentally, and potentially contribute to increasing the capacity of IoT tags within a single wireless network while reducing maintenance effort.
ELECTRONICS LETTERS
(2022)
Article
Multidisciplinary Sciences
Daiju Ushikoshi, Riku Higashiura, Kaito Tachi, Ashif Aminulloh Fathnan, Suhair Mahmood, Hiroki Takeshita, Haruki Homma, Muhammad Rizwan Akram, Stefano Vellucci, Jiyeon Lee, Alessandro Toscano, Filiberto Bilotti, Christos Christopoulos, Hiroki Wakatsuchi
Summary: Metasurface-based antennas can adjust antenna performances according to the time width of electromagnetic pulses, which advances the design of antennas and wireless communication environments. The proposed concept goes beyond conventional performance and can be applied for sensing, selective reception, and mutual communications based on pulse width, thus expanding existing frequency resources.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Shiori Imai, Haruki Homma, Kairi Takimoto, Mizuki Tanikawa, Jin Nakamura, Masaya Kaneko, Yuya Osaki, Kiichi Niitsu, Yongzhi Cheng, Ashif Aminulloh Fathnan, Hiroki Wakatsuchi
Summary: This study demonstrates numerically that the response of circuit-based metasurfaces can be characterized by their circuit parameters. The metasurfaces, consisting of a four-diode full wave rectifier, can sense different waves based on the incident waveform, specifically the pulse width. The study reveals the relationship between the electromagnetic response of waveform-selective metasurfaces and the SPICE parameters of the diodes used, providing design guidelines for optimal diodes selection and enhancing performance in various applications.
SCIENTIFIC REPORTS
(2023)
Article
Engineering, Electrical & Electronic
Yongzhi Cheng, Yingjie Qian, Haruki Homma, Ashif Aminulloh Fathnan, Hiroki Wakatsuchi
Summary: In this study, two types of waveform-selective microwave metasurface absorbers (MMAs) were numerically and experimentally demonstrated. By designing specific circuit and geometrical parameters, these absorbers can selectively absorb signals of specific waveforms at the same frequencies, including higher-order modes. These waveform-selective MMAs have a wide range of applications in electromagnetic shielding, detection, sensing, and wireless communications.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Nanoscience & Nanotechnology
Kairi Takimoto, Hiroki Takeshita, Ashif Aminulloh Fathnan, Daisuke Anzai, Shinya Sugiura, Hiroki Wakatsuchi
Summary: We propose a novel concept of metasurface filters that can selectively extract pulsed waveforms at a constant frequency from complex superimposed input signals. Our filters overcome the challenge of eliminating unnecessary pulses under simultaneous incidence without relying on commonly used modulation schemes. By integrating waveform-selective metasurface unit cells with delay lines and interference cancellation processes, our concept allows for simultaneous filtering and can be extended to incorporate broadband signals and other modulation scheme variables. This study opens up new possibilities for controlling electromagnetic waves and has potential applications in wireless power transfer and communications.
Article
Physics, Applied
Hiroki Takeshita, Daisuke Nita, Yongzhi Cheng, Ashif Aminulloh Fathnan, Hiroki Wakatsuchi
Summary: In this study, a design method for waveform-selective metasurface absorbers operating in multiple frequency bands is presented and validated through numerical and experimental verification. The method allows the absorbers to preferentially absorb target electromagnetic waves of the same frequency based on the incident waveform, specifically the pulse width. By adjusting the spatial ratio of unit cells assigned to different frequencies, the performance of the dual-band approach is enhanced. This study opens up possibilities for the utilization of waveform-selective metasurfaces in diverse frequency bands, providing a valuable and versatile solution for various applications.
APPLIED PHYSICS LETTERS
(2023)
