Shielding digital electronics

Electromagnetic sources and signals abound in today's world. They are a result of our security systems, our computers, our autos and our aircraft. Unfortunately, the exposure of electronic devices and systems to these signals can disrupt their operation. High power microwave signals can be particularly damaging and can lead to disastrous results.

There is an urgent need to better understand and model the effects of electromagnetic field interactions with electronic circuits and systems over a very wide range of frequencies. This need can arise from an interest in protecting a system from harmful electromagnetic signals, or from a desire to exploit knowledge gained for the purpose of disrupting the performance of an adversary's system.

The Applied Electromagnetics program at Clemson University, along with a consortium of other universities, has undertaken a research initiative administered by the Air Force Office of Scientific Research. Results of the research will be made available to a committee

charged with developing protection methods against deliberate exposure of civilian and defense systems to high power microwave sources.

"There is worry about what a person with a briefcase-size microwave generator near a runway or highway can do to an aircraft or to an automobile," says Professor Chalmers Butler.

"This subject is of interest to the Air Force for a number of reasons which have to do with the design of weapons based upon high power microwave sources and with protection against the effects of such weapons, but they want us to be cognizant of aspects which pertain to terrorism."

The goal is to understand how high power microwave signals can influence the operation of modern digital electronics deeply embedded within a system. Anything that depends upon digital electronics is within the purview.

Researchers will investigate general principles pertaining to how one might shield against high power microwave sources. Members of the multi-university team specialize in electromagnetic coupling, topology, reaction of solid state devices to spurious signals, and digital systems.

Clemson will participate in the development of appropriate specifications and international standards for testing and hardening procedures for systems against ultrawide-band and high power microwave sources.

The end product will include methods by which a user can understand the response of a typical system to an electromagnetic signal and can acquire the background needed to fashion a signal source, so that the operation of hostile systems can be disrupted.