Discussion of ultra wideband electromagnetic phenomena, applications and measurement has been an active and sometimes controversial subject for 20 years [1-4]. Even definition of "ultra wideband" has often been argued. Specific controversy surrounds claims of UWB advantages for radar target identification and discrimination, measurement of material properties and electromagnetic response of appliqués. In the last 10 years, UWB communication, receivers and transmitter configurations, thin antennas and high power sources, UWB antenna and High Power Electromagnetic Fields, have achieved quantum leaps in capability. Electromagnetic material and structure performance has been extended by MetaMaterials and new phenomena in negative index-left handed materials and other electromagnetic structures that have resonant responses to incident electromagnetic waves. Power-aperture products and power densities in current and future systems must include consideration of nonlinearity in electromagnetic interaction with materials, structures and microwave devices. Appropriate study at high powers requires extension of existing codes, improved measurement facilities, antennas, sources, etc. In summary it is necessary that the electromagnetic modeling, demonstration and implementation cycle be restarted.

1. Ultra-Wideband Radar: Proceedings of the First Los Alamos Symposium, Ed. Bruce Noel, CRC Press, 1990
2. Ultra-Wideband, Short Pulse Electromagnetics, 4, Editor Heyman et.al, Plenum Publishers, 1999.
3. Jasons Report, JSR-04-210, Feb. 3, 2005, Mitre Corporation
4. Dvorak S., IEEE Trans. EMC, V 37, No 2, p. 192, May 1995.