Radio Science Bulletin 313 - June 2005 - URSI

Radar / CommunicationsBand TypeElectromagnetic InterferenceFractional BandwidthBF=f − ff + f2 h lhlBand Ratio 1fhbr=flNarrowband (NB) Hypoband (NB) 0.00 < B F ≤ 0.01 0.00 < b r ≤ 1.01Wideband (WB) Mesoband (MB) 0.01 < B F ≤ 0.25 1.01 < b r ≤ 1.29Ultra-Wideband (UWB)Sub-Hyperband (SHB) 0.25 < B F ≤ 1.50 1.29 < b r ≤ 7.00Hyperband (HB) 1.50 < B F < 2.00 7.00 < b r < ∞Table 1: Modified Classification Scheme for Devices/Signals based on Bandwidthconventional systems and UWB systems is more a smoothtransition than a hard limit. Since this transition cannot bequantified with mathematical exactitude or by a frequencydependenttechnological step for most applications, everydemarcation threshold has to be chosen somewhat arbitrarilyrelative to existing heuristic knowledge of pertinentstandardization committees or scientific communities. Forexample, under the following three-band classificationscheme, the OSD/DARPA Review Panel [1] stated thatsignals having fractional bandwidths greater than 0.25 areUWB:Narrowband, if 0.00 < B F < 0.01;Wideband, if 0.01 < B F ≤ 0.25 ;Ultra-wideband, if 0.25 < B F < 2.00 .Since the basic principle of the above categorization criteriameets the needs of the communications community, theFCC adopted most of it. However, in the most recentversion of the FCC Part 15 rules, the demarcation betweenwideband and UWB was decreased to 0.20.Because practical waveforms of impulse-basedsystems (like impulse-radiating antennas) have fractionalbandwidths exceeding 1.9, the IEC Technical Committee77C, in their most recent draft of electromagneticcompatibilitystandards, suggests a four-band classificationscheme:Narrowband, 0.00 < B F < 0.01,0.00 < ≤ 1.01 ;Mesoband, 0.01 < B F ≤1.001.01 < b r ≤ 3.00 ;Sub-Hyperband, 1.00 < B F ≤ 1.63 ,3.00 < ≤ 10.00 ;b rb rHyperband, 1.63 < B F < 2.00 ,10.00 < br