Robert Johnk

Robert (Bob) Johnk (M’91 – SM’07) received his Ph.D. in Electrical Engineering at the University of Colorado in 1990, where he specialized in electromagnetics and antennas. Bob recently retired as a research engineer from the Institute for Telecommunication Sciences (NTIA/ITS). He was engaged in advancing the state of the art in radio-channel propagation measurements/analysis and mentoring new engineers in the art of measurement science. 

EMC Challenges for Electric Vehicles

With electric vehicles gaining market share, their challenges with electromagnetic compatibility (EMC) are being magnified. Electromagnetic noise sources, such as high power switching operations, can cause regulatory compliance and self-compatibility issues. Understanding these potential issues early in the product lifecycle can inform EMC-friendly design choices. Power electronics, cable routing, cable shielding, simulation and modeling, and other disciplines all have a part to play in contributing to success or failure in this area. In this free-form panel discussion, experts Garth D’Abreu, Craig Fanning, and Karen Burnham sit down to discuss the regulatory environment, the main challenges in both the design and testing of EVs, and the best strategies for overall EMC success in the EV space.

Relevant Standards Discussed  >

EMI Standards for Mobility:

ADAS EMC Testing or Vehicle Antenna Measurement

Anechoic chambers in their various iterations have been around for several decades; the basic principles are fairly well understood and chambers are routinely designed to meet a wide range of test requirements.  In this talk, Mr. Garth D’Abreu discusses the main factors affecting EMC chamber designs for testing EVs with specific emphasis on the importance of RF absorber performance and chamber layout. He also looks at some of the compromises involved in optimizing a design for a specific application, and the guidance provided in current EMC test standards for compliant test sites.

EMI Standards for Mobility:

Noise Sources in EV

With Electric Vehicles (EVs) becoming more common, the electromagnetic noise they generate is an issue that more designers must face. Karen Burnham, Principal Scientist at Electro Magnetic Applications, brings lessons learned from years of troubleshooting hybrid and plug-in electric vehicles to discuss some of the most important EV noise factors.

EMC Design and Test Challenges in Telecom Equipment

The first webinar in this series reviews how the data transmission speeds of telecommunication/networking equipment, its copper and optical I/O interface densities, and its system power requirements continue to increase. Each attribute presents its own sets of Electromagnetic Compatibility (EMC) challenges in both design and testing for immunity and emissions. In this presentation, Dr. Alpesh U. Bhobe provides an overview of these challenges and how they are being mitigated. The talk covers design and verification methodologies at a component level (e.g., power supply, Integrated Connector Module (ICM), and/or Optical Module) and the system level.

EMC Wearable Devices 

This talk explores the primary EMI mechanism of external electromagnetic fields in wearable devices in healthcare applications. It introduces two innovative examples: a wearable electrocardiogram (ECG) and a wearable robotic hand. These devices integrate vital sensors and human body communication technology, enabling new applications and capabilities.

The presentation delves into the fundamental electromagnetic interference (EMI) mechanism that affects wearable devices, focusing on converting from common mode to differential mode. By understanding this mechanism, designers can identify potential issues and develop effective countermeasures at the design stage to enhance device performance. Furthermore, the talk showcases an immunity test system specifically designed for wearable devices. This system provides a comprehensive evaluation of the device's ability to withstand electromagnetic interference, ensuring its reliability and functionality in various environments.

In this talk, Professor Jianqing Wang provides valuable insights into wearable device technology, addressing EMI challenges and offering practical solutions for design optimization and robustness. It contributes to the advancement of wearable devices, fostering their integration into healthcare and robotics domains for improved quality of life and enhanced human-machine interactions.