Publications de Mingxiang Gao | EPFL Graph Search

A 49.8-mm 2 IR-UWB Transmitter With Co-Designed Power Amplifier and Antenna for Neural Implants With Extended Transmission Range

Anja Skrivervik, Mahsa Shoaran, Mingxiang Gao, Cong Ding

This work presents an implantable impulse-radio ultrawideband transmitter (IR-UWB TX) optimized for high-density neural recording. To address the tradeoffs between data rate, transmission range, implant size, and power consumption, we propose a novel co-de ...

Institute of Electrical and Electronics Engineers (IEEE)2025

Closed-Form Approximations for RF Radiation from Implantable Medical Devices

Anja Skrivervik, Mingxiang Gao

The radio frequency (RF) performance of implantable antennas is significantly affected by the lossy biological tissues surrounding the implant. This paper introduces an an-alytical method for assessing the gain and radiation patterns of implantable antenna ...

IEEE2025

A Hybrid Method for Optimizing Radiation of Implantable Antennas in Diverse Scenarios

Anja Skrivervik, Mingxiang Gao

This paper presents a combination of three computational methods in a hybrid approach designed to model the radiation of antennas within arbitrarily shaped capsules implanted in a host body. A surface method of moments is employed to represent the radiatio ...

IEEE2025

Cylindrical Phantom Model for Characterization of Implantable Antennas

Anja Skrivervik, Mingxiang Gao

Fundamental radiation limitations for in-body or implantable antennas provide valuable insights into the feasibility of certain systems. Previous work has shown that near-field effects and the distance from the body-to-freespace boundary are critical facto ...

IEEE2025

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

Spherical Human Phantoms for Characterization of Implanted Antennas

Anja Skrivervik, Mingxiang Gao

Implantable antennas cannot be characterized by methods suitable for standard antennas because they are embedded in lossy human tissue, which affects the antenna parameters. In this paper, we consider a canonical spherical human phantom which allows us to ...

Institute of Electrical and Electronics Engineers Inc.2024

Link Budget Estimation for Implantable Antennas: From In-Body Coupling to Free-Space Radiation

Anja Skrivervik, Mingxiang Gao, Sujith Raman

In wireless communication systems, the Friis transmission equation is commonly used to quickly estimate wireless transmission efficiency between the transmitter and the receiver. In the case of wireless implantable bioelectronic systems, the gain of the im ...

Institute of Electrical and Electronics Engineers Inc.2024

Maximum Radiation Efficiency of Arbitrarily Shaped Implantable Antennas

Anja Skrivervik, Mingxiang Gao

Performance limitations for implanted antennas, taking radiation efficiency as the metric, are presented. The performance limitations use a convex optimization procedure with the current density inside the implant acting as its degree of freedom. The knowl ...

2024

Electromagnetic Radiation of Implantable Antennas

Mingxiang Gao

In the development of implantable bioelectronics, the establishment of efficient wireless RF links between implants and external nodes is crucial, providing substantial contributions to the advancement of medical diagnosis, therapies, and basic science. Im ...

EPFL2024

Analytic Approximation of Free-Space Path Loss for Implanted Antennas

Anja Skrivervik, Mingxiang Gao, Sujith Raman

Implantable wireless bioelectronic devices enable communication and/or power transfer through RF wireless connections with external nodes. These devices encounter notable design challenges due to the lossy nature of the host body, which significantly dimin ...

2024

Wireless, battery-free, and real-time monitoring of water permeation across thinfilm encapsulation

Yves Leterrier, Anja Skrivervik, Stéphanie Lacour, James Daniel Rosenthal, Mingxiang Gao, Massimo Mariello

Long-term bioelectronic implants require stable, hermetic encapsulation. Water and ion ingress are challenging to quantify, especially in miniaturized microsystems and over time. We propose a wireless and battery-free flexible platform leveraging backscatt ...

Springer Science and Business Media LLC2024

A 3 mm2, Energy-Efficient, Multi-Data-Rate, FDMA Transmitter with On-Chip Antenna for Next-Generation Neural Implants

Anja Skrivervik, Mahsa Shoaran, Mingxiang Gao, Cong Ding

This paper presents a versatile energy-efficient wireless transmitter (TX) for neural implants with high/ultrahigh channel counts. The TX supports a wide range of data transmission rates, from 50Mb/s to 1.2 Gb/s, through a novel dual-modulation approach. O ...

IEEE2024

Analytical Model for Calculating Gain Pattern of Antennas Implanted in Large Host Bodies

Anja Skrivervik, Mingxiang Gao, Sujith Raman

This communication presents a method for the fast and accurate estimation of the gain pattern and maximum gain of an implanted antenna including the effect of the host body, under the assumption that the latter is electrically large. The estimation procedu ...

2024

A 49.8mm2 Fully Integrated, 1.5m Transmission-Range, High-Data-Rate IR-UWB Transmitter for Brain Implants

Anja Skrivervik, Mahsa Shoaran, Mingxiang Gao, Cong Ding

Implantable neural interfaces hold great potential to restore function in individuals impaired by paralysis, limb amputations, or various neurological conditions. The need for precise mapping of neuronal activity across various brain regions and enhancing ...

IEEE2024

Maximum Radiation Efficiency of an Implantable Antenna: The Role of High-Order Modes

Anja Skrivervik, Mingxiang Gao, Jakub Liska

A combination of two numerical techniques of computational electromagnetics, namely, method of moments and vector spherical wave expansion, is used to show performance limitations on the radiation efficiency of implantable antennas and to efficiently resol ...

IEEE2023

Radiation Performance of Antennas Implanted in Small Animals for Neuroengineering

Anja Skrivervik, Stéphanie Lacour, James Daniel Rosenthal, Mingxiang Gao, Kangling Wu, Zvonimir Sipus

Wireless data communication could improve the performance and reliability of biomedical implants used in fundamental neuroscience research by removing infection-prone transcutaneous cabling. The small size of common research animals like mice and rodents, ...

IEEE2023

Radiation Patterns of RF Wireless Devices Implanted in Small Animals: Unexpected Deformations Due to Body Resonance

Anja Skrivervik, Stéphanie Lacour, James Daniel Rosenthal, Mingxiang Gao, Kangling Wu, Zvonimir Sipus, German Augusto Ramirez Arroyave

One challenge in designing RF wireless bioelectronic devices is the impact of the interaction between electromagnetic waves and host body tissues on far-field wireless performance. In this paper, we investigate a peculiar phenomenon of implantable RF wirel ...

2023

Characterization of a Miniature Broadband Antenna for Implantable Neuromodulation Devices

Anja Skrivervik, Mingxiang Gao

Fully implantable wireless telemetry systems improve the performance and reliability of neural interfaces by eliminating infection-prone percutaneous cables. Meanwhile, wireless links with high data rates are required to meet the growing demand for high-de ...

Institute of Electrical and Electronics Engineers Inc.2023

Analytic Approximation of In-Body Path Loss for Implanted Antennas

Anja Skrivervik, Mingxiang Gao, Zvonimir Sipus

Implantable bioelectronic devices predominantly use wireless links for communication and/or power transfer. When considering transmitting implanted antennas, electromagnetic radiation through biological media is highly attenuated, and previous work has sho ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2023

On the Maximum Power Density of Implanted Antennas within Simplified Body Phantoms

Anja Skrivervik, Mingxiang Gao, Zvonimir Sipus

With the application requirements of wireless technology in implantable bioelectronics, knowledge of the fundamental limits for implanted antennas becomes critical. In this work, we investigated the variation of maximum power density within simplified body ...

IEEE2022