Publications by Denys Nikolayev

Novel 2-D Beamsteerable Rectenna with Improved Power Receptivity for mm-Wave RF-WPT Applications

Anja Skrivervik, Denys Nikolayev, German Augusto Ramirez Arroyave, Amir Mohsen Ahmadi Najafabadi

This paper introduces a novel 2-D beam-steerable rectenna designed for mm-wave RF wireless power transfer (RF-WPT) applications. The 2-D beamsteering capability of the proposed rectenna is achieved by integrating an on-chip 4 × 4 Butler matrix, which is co ...

2025

Physical insights and design principles for efficient wireless implantable bioelectronics

Anja Skrivervik, Denys Nikolayev, Mingxiang Gao

Implantable bioelectronics require highly efficient wireless connectivity for autonomous operation and closed-loop control, yet power constraints, safety regulations, and data transmission limitations continue to hinder advancements in medical device innov ...

2025

Analysis of Non-Canonical Body-Conformal Arrays with Polarization Decomposition

Anja Skrivervik, Denys Nikolayev

Conformal phased arrays can be found in many applications due to their ability to fit tridimensional surfaces and, thanks to their scanning performance, can excel planar arrays. However, most of the previously proposed analysis methods can be applied only ...

IEEE2023

Theoretical Efficiency and Dosimetry of Buffered On-body Transmitter Antennas for Wireless Powering of In-body Devices

Anja Skrivervik, Denys Nikolayev

The viable and safe application of wireless power transfer for powering bioelectronic implants requires understanding the wave propagation in heterogeneous and dispersive media, the electromagnetic exposure assessment, and the optimum design of the system ...

IEEE2022

Reconfigurable Dual-Band Capsule-Conformal Antenna Array for In-Body Bioelectronics

Anja Skrivervik, Denys Nikolayev

Wireless in-body bioelectronics offer powerful biosensing and therapeutic capabilities. Efficient and robust in-body antenna designs are required to ensure a reliable through-body link, increase data rates, and reduce power budgets. This study proposes and ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Wireless Powering Efficiency of Deep-Body Implantable Devices

Anja Skrivervik, Denys Nikolayev, Zvonimir Sipus, Mingxiang Gao, Erdem Cil

The wireless power transfer (WPT) efficiency to implanted bioelectronic devices is constrained by several frequency-dependent physical mechanisms. Recent works have developed several mathematical formulations to understand these mechanisms and predict the ...

Institute of Electrical and Electronics Engineers2022

Physical Bounds on Implant Powering Efficiency Using Body-Conformal WPT Systems

Anja Skrivervik, Denys Nikolayev, Zvonimir Sipus, Mingxiang Gao

The efficiency of an on-body wireless power transfer system for implant powering is defined by how the electromagnetic energy interacts with the lossy, heterogeneous, and dispersive body tissues. The objective of this study is to discuss the methodology an ...

IEEE2021

Rules of Thumb to Assess Losses of Implanted Antennas

Anja Skrivervik, Denys Nikolayev, Zvonimir Sipus, Mingxiang Gao

Fundamental limits for implanted antennas should be able to evaluate the bounds on losses with the knowledge of physical limitations from antenna and tissue parameters. In this work, rules of thumb to assess losses of deeply implanted antennas are presente ...

IEEE2021

Propagation-Loss Characterization for Livestock Implantables at (433,868,1400) MHz

Denys Nikolayev

Automated systems based on wearable sensors for livestock monitoring are becoming increasingly popular. Specifically, wireless in-body sensors could yield relevant data, such as ruminal temperature. The collection of such data requires an accurate characte ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2021

Application of Fundamental In-Body Radiation Limitations to Practical Design of Antennas for Implantable Bioelectronics

Anja Skrivervik, Denys Nikolayev

Fundamental in-body limitations on achievable radiation efficiency could provide decision-making assistance to engineers working on antennas for implantable bioelectronics. In this study, proof-of-concept conformal microstrip antennas are proposed based on ...

IEEE2020