Article
Instruments & Instrumentation
Hao Deng, Yiqing Wei, Huihui Jing, Rui Zhang, Qinwen Chen, Jiayun Wang, Zeng Qu, Junping Duan, Binzhen Zhang
Summary: This paper presents a flexible ultra-wideband (UWB) and deformation-insensitive antenna. The antenna is based on a Mickey-shaped patch, a coplanar waveguide fed, and a flexible composite substrate. The dielectric properties of the substrate are modified and controlled using different fillers, and the PDMS-based composites are characterized. The proposed antenna is fabricated and measured, demonstrating stable performance and safety in proximity to the human body.
SMART MATERIALS AND STRUCTURES
(2022)
Article
Engineering, Electrical & Electronic
Takuya Kaji, Hiroyasu Sato, Qiang Chen, Shimpei Nagae, Akira Kumagai, Osamu Kagaya
Summary: This article proposes a leaky wave antenna with a dielectric superstrate (LWADS) on a perforated dielectric spacer. The LWADS has an asymmetric structure with a half-filled dielectric spacer and a non-filled spacer, creating a quasi-cutoff region. The beam direction of the leaky wave is controlled by changing the hole radius of the periodically perforated, half-filled dielectric spacer. Measurements at X-band confirm the effectiveness of the design, demonstrating a high gain tilted beam pattern with peak gains of 14 dBi at theta = 20 degrees, 40 degrees, and even at a wide-angle of theta = 60 degrees. The ability to control the effective permittivity through the hole radius allows for the realization of an array of LWADS with different beam angles and a multibeam antenna with switched feeding.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Chemistry, Physical
Magdalena Niziol, Piotr Jankowski-Mihulowicz, Mariusz Weglarski
Summary: Antennas dedicated to RFID systems on textile substrates need to maintain specific parameters. Washing can cause mechanical and chemical degradation of the antenna materials, leading to changes in antenna parameters. Experimental dipole antennas were created and washed to measure the impedance parameters, finding that these parameters change during washing due to factors such as fabric shrinkage.
Article
Chemistry, Multidisciplinary
Muhammad Usman Ali Khan, Raad Raad, Faisel Tubbal, Panagiotis Ioannis Theoharis
Summary: This study practically analyzed the bending capabilities of flexible antennas on polymer substrates by fabricating antennas operating at different frequencies on PET, PTFE, and PVC substrates. The study focused on investigating the flexibility and bending ability of polymer materials, and their tendency to withstand deformation.
APPLIED SCIENCES-BASEL
(2021)
Article
Physics, Multidisciplinary
Meng Wang, Zhifu Liu, Jian Dong
Summary: This article proposes a dual-band slot IFA antenna using a combined technique of liquid metal filling and polydimethylsiloxane substrate. The antenna can work at 2.4 and 5.8 GHz and is suitable for flexible, conformal, and wearable applications.
FRONTIERS IN PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Mucahit Alcep, Fikret Tokan
Summary: This paper proposes an innovative method to eliminate internal reflections at the lens/air boundary of radar sensors using dielectric lenses made of dense materials. Instead of traditional broadband matching techniques, an alternative matching technique compatible with today's 3D printing technology is introduced. This simple, cost-effective matching technique involves using the material of the lens itself, and has been successfully confirmed through simulations and experiments.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Lingnan Song, Botian Zhang, Daisong Zhang, Yahya Rahmat-Samii
Summary: This article presents systematic modeling and optimization strategies for designing embroidery electrotextile patch antennas, aiming to improve both accuracy and efficiency. Material characterization, detailed modeling, stitch density study, and surrogate-based optimization are implemented to achieve the desired outcomes.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
Ma Boyuan, Jin Pan, Deqiang Yang, Yong-Xin Guo
Summary: The homogenization theory for stacked dielectric resonator antennas (DRAs) on planar and curved ground planes is investigated in this study. The commonly used static capacitance models are reevaluated to reveal and analyze their deficiencies. To improve these models, the effective medium theory is introduced to provide better empirical equations. Moreover, a resonance-based homogenization methodology with explicit physical intention is developed. The performance of each method is discussed based on error analysis using a set of DRA samples.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
Jen-Hahn Low, Pei-Song Chee, Eng-Hock Lim
Summary: For the first time, a wearable antenna incorporating liquid metal and an elastomer platform has been designed. The liquid metal is injected into a flexible substrate to create a fluidic slot antenna and a liquid EBG structure, which mitigates the effects of the human body and improves antenna performance. The antenna has a high gain and low specific absorption rate, and its impedance bandwidth is stable even in humid environments.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Computer Science, Information Systems
Tu Tuan Le, Yong-Deok Kim, Tae-Yeoul Yun
Summary: This paper presents a triple-band open-ring high-gain high-efficiency antenna for 2.45/3.0/3.45 GHz wearable applications, with features such as directional radiation pattern, high gain, high efficiency, low SAR, and comfortability for wearers. Through a complex structure design, the antenna achieves excellent performance.
Article
Computer Science, Information Systems
Hamza A. Mashagba, Hasliza A. Rahim, Ismahayati Adam, Mohd Haizal Jamaluddin, Mohd Najib Mohd Yasin, Muzammil Jusoh, Thennarasan Sabapathy, Mohamedfareq Abdulmalek, Azremi Abdullah Al-Hadi, Arif Mawardi Ismail, Ping Jack Soh
Summary: This paper introduces a hybrid mutual coupling reduction technique applied to a dual-band textile MIMO antenna, resulting in significant suppression of mutual coupling and maintenance of wideband impedance bandwidth through the introduction of a line patch and patch rotation technique. The proposed antenna exhibits robust performance under various bending configurations, achieving good agreements between simulated and measured results in both planar and bending conditions. With a low mutual coupling, high diversity gain, and maintained gain even under bending conditions, the antenna shows promise for wireless body area network and 5G applications.
Article
Computer Science, Information Systems
Umar Musa, Shaharil Mohd Shah, Huda A. Majid, Ismail Ahmad Mahadi, Mohamad Kamal A. Rahim, Muhammad Sani Yahya, Zuhairiah Zainal Abidin
Summary: This paper presents the design and analysis of a compact dual-band wearable antenna for WBAN applications. The antenna is prototyped on a semi-flexible Rogers Duroid RO3003 with compact dimensions of 41x44 mm^2. It resonates at 5.8 GHz and an inverted U-shaped slot is added to create resonance at 2.4 GHz. Additional slots and partial ground help enhance bandwidth and gain. The antenna meets FCC and ICNIRP standards and is suitable for WBAN applications.
Proceedings Paper
Engineering, Electrical & Electronic
Shengjian Jammy Chen, Zhihan Xu, Christophe Fumeaux
Summary: This paper presents a wearable wideband textile patch antenna with two parasitic shorted strips for off-body communications. The antenna exhibits excellent mechanical resilience and a wide bandwidth, covering part of the 5GHz WLAN bands and the 5.8GHz ISM bands.
2022 16TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)
(2022)
Article
Engineering, Electrical & Electronic
Payal Bhardwaj, Ritesh Kumar Badhai
Summary: A wearable microstrip UWB antenna using jeans textile material as a substrate is introduced and examined. The antenna design incorporates copper tape and copper wire as conducting materials for the patch and ground respectively. The optimized annular ring structure with connecting feed achieves an impedance bandwidth of 24.13 GHz and a peak gain of 10.93 dB at 14.80 GHz. The antenna design is validated for wearable telemetry applications with low Specific Absorption Rates (SAR) of 1.23W/kg, 1.26W/kg, and 0.64W/kg averaged over 1-g of tissue for arm, leg, and head respectively at 2.45 GHz. Additionally, the proposed design is analyzed for different bent radii suitable for wearable applications, and the measured results align well with the simulated results.
IETE JOURNAL OF RESEARCH
(2023)
Article
Engineering, Electrical & Electronic
Ankur Utsav, Ritesh Kumar Badhai
Summary: This paper proposes the design and analysis of an electrically small eight-shaped wearable antenna for on- and off-body communication. The antenna has a compact size and resonates at 2.4 GHz. It exhibits good gain, omnidirectional radiation pattern, and low specific absorption rate (SAR). The bending analysis and size limitations are also discussed, confirming its practical use.
Article
Multidisciplinary Sciences
Mohamad J. Hajiahmadi, Reza Faraji-Dana, Anja K. Skrivervik
Summary: The use of metamaterial structure and time-reversal technique enables superlensing with lambda /10 resolution inside biological tissues. An imaging scheme is proposed with an entropy criterion to reduce the number of required optical transducers for reconstructing the diffusion pattern of a diffusive material inside tissues, resulting in super-resolution images.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Electrical & Electronic
Zvonimir Sipus, Anna Susnjara, Anja K. Skrivervik, Dragan Poljak, Marko Bosiljevac
Summary: The design of medical sensor implants and prediction of communication link efficiency in the human body are studied, showing that the uncertainty of body tissues' constitutive parameters affects radiation efficiency prediction and some tissue parameters have dominant influence on uncertainty.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Mohsen Koohestani, Anja K. Skrivervik, Mohamed Ramdani
Summary: A new technique involving a suspended metal loop to reduce far-field emission and susceptibility of PCBs has been proposed, with analytical predictions of electromagnetic field distribution at very large distances. The methodology showed good approximation of far-field EMFs with low RMSE values and significantly reduced computational time compared to full-wave numerical analysis. It was effective for various radiator sizes and frequencies, and achieved good precision for emitting ICs regardless of size and frequency.
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
(2021)
Article
Engineering, Electrical & Electronic
Denys Nikolayev, Anja K. Skrivervik, John S. Ho, Maxim Zhadobov, Ronan Sauleau
Summary: Efficient and robust in-body antenna designs are crucial for the development of wireless in-body bioelectronics. This study proposes a pattern- and frequency-reconfigurable capsule-conformal antenna array that addresses the challenges of next-generation in-body bioelectronics, and experimental results validate its effectiveness.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Computer Science, Information Systems
Mohsen Koohestani, Nima Azadi-Tinat, Anja K. Skrivervik
Summary: In this paper, a compact asymmetric coplanar strip (ACS)-fed monopole antenna is proposed for simultaneous operation within the Bluetooth and UWB frequency bands while rejecting the lower WLAN interfering band. The antenna achieves this by incorporating inverted right triangle patch monopole and open-ended L-shaped slits. The prototype of the antenna demonstrates excellent performance with a small size and stable omni-directional radiation patterns.
Article
Engineering, Electrical & Electronic
Ben A. P. Nel, Anja K. Skrivervik, Mats Gustafsson
Summary: Antenna bounds are useful for assessing antenna design feasibility and performance. This article presents tight lower bounds on microstrip patch antennas with infinite dielectric substrate, which are significantly tighter than the Chu limit and introduce a new scaling rule. The bounds consider all possible geometries and show that well-known patch antennas have near-optimal bandwidth. The computation of the bounds is done using a method of moments (MoM) formulation, and an approximation using commonly available simulation tools is provided.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Engineering, Electrical & Electronic
Icaro V. Soares, Mingxiang Gao, Erdem Cil, Zvonimir Sipus, Anja K. Skrivervik, John S. Ho, Denys Nikolayev
Summary: This article proposes an approach to analyzing efficiency in anatomical models, which is validated using a theoretical spherical wave expansion analysis. The results show that a magnetic receiver outperforms an electric one in the near-field operation, while both sources are equally effective in the far-field range. The maximum efficiency is achieved in the mid-field with an optimum frequency between 1 and 5 GHz depending on the implantation depth. Receiver orientation also significantly affects the efficiency. The proposed approach is applied to a case of a deep-implanted pacemaker powered wirelessly by an on-body transmitter and subjected to stochastic misalignments. Design guidelines for optimal implantable WPT systems are established based on the results obtained.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Engineering, Electrical & Electronic
Yuanyan Su, Christoph Affolderbach, Matthieu Pellaton, Gaetano Mileti, Anja K. Skrivervik
Summary: A new type of micro-loop-gap microwave resonator (mu-LGR) is proposed to miniaturize the double-resonance (DR) rubidium vapor-cell atomic clocks, providing more design degrees of freedom and a wider tuning range of the resonances. An equivalent circuit model and different tuning schemes are discussed to demonstrate the wide tuning mechanism. The proposed compact tunable mu-LGR achieves a 40% volume reduction, comparable magnetic field quality, and an enlarged frequency tuning range.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Engineering, Electrical & Electronic
Mingxiang Gao, Zvonimir Sipus, Anja K. Skrivervik
Summary: Implantable bioelectronic devices often use wireless links for communication and power transfer. This study focuses on the near-field losses of implanted antennas, which are significant due to the attenuation of electromagnetic radiation through biological media. A simplified model is presented, providing closed-form approximate expressions to estimate EM radiation from the implant, taking into account the implantation depth. The proposed method is verified by comparing the results with full-wave simulations and practical examples found in the literature.
IEEE OPEN JOURNAL OF ANTENNAS AND PROPAGATION
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Icaro Soares, Anja K. Skrivervik, Denys Nikolayev
Summary: The study focuses on the viable and safe application of wireless power transfer for bioelectronic implants. It analyzes the wave propagation in heterogeneous and dispersive media, electromagnetic exposure assessment, and optimum design of system parameters to achieve a trade-off between efficiency and specific absorption rate levels. Through a case study of a wirelessly charged deep-implanted pacemaker, the optimal configuration of transmitter dimensions and electromagnetic properties is determined. The study also compares this configuration to a magnetic counterpart to investigate suboptimal performance.
2022 16TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Ismael Vico Trivino, Anja K. Skrivervik
Summary: In this paper, we propose a technique to broaden the beamwidth of conventional patch microstrip antennas by using parasitic elements. This technique allows maintaining the main advantages of microstrip antennas while increasing their beamwidth. Guidelines on tuning key parameters to switch from directive patterns to broad beams are provided.
2022 16TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Mingxiang Gao, Zvonimir Sipus, Anja K. Skrivervik
Summary: This study investigated the fundamental limits of implanted antennas in the body and derived design rules that can be used as benchmarks for most implanted antenna designs, especially for shallow implants.
2022 16TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Tingyong Jiang, Anja K. Skrivervik
Summary: This paper proposes a novel approach based on the Monte-Carlo method to assess the distribution of electromagnetic field exposure in a specific deployment scenario. By considering the non-uniform user distribution, the realistic assessment of EMF exposure in a particular coverage area of a 5G base station is achieved. The simulated results demonstrate that considering the user distribution significantly reduces the exposure distribution and provides a reliable basis for exposure evaluation and service quality control.
2022 16TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)
(2022)
Proceedings Paper
Automation & Control Systems
E. Batori, C. Affolderbach, M. Pellaton, F. Grnet, G. Mileti, Y. Su, M. Violetti, A. K. Skrivervik
Summary: The study presents experimental results on double-resonance Ramsey spectroscopy in a micro fabricated Rb vapor cell, showing high stability performance and potential support for future improved miniature atomic clocks.
2021 JOINT CONFERENCE OF THE EUROPEAN FREQUENCY AND TIME FORUM AND IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM (IEEE EFTF-IFCS 2021)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Mingxiang Gao, Denys Nikolayev, Marko Bosiljevac, Zvonimir Sipus, Anja K. Skrivervik
Summary: This study presents rules of thumb to assess losses of deeply implanted antennas and calculates radiation efficiency of an elementary antenna within a spherical phantom. It highlights the key role of losses from different contributions in specific situations.
2021 15TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)
(2021)