Patent ID: 6037546
Filing Date: 2000-03-14
Classification: H01B

Abstract:
A communications cable for use in plenum applications, said cable comprising:a plurality of conductors, each being individually enclosed by a substantially pure high density polyethylene (HDPE) insulation material, said plurality of conductors being configured as a plurality of twisted pairs arranged in a conductor core, each of said twisted pairs having a different twist length associated therewith;a polyvinylidene fluoride (PVDF) outer jacket surrounding said plurality of conductors;wherein said plurality of twisted pairs, said insulation material, and said outer jacket are cooperatively configured such that said communications cable passes the UL-910 plenum burn test, said cable meets the physical requirements set forth in the UL-444 communications cable standard, and the near end crosstalk (NEXT) loss for the worst-case combination of two of said twisted pairs, measured in decibels at 100 MHZ, is greater than or equal to:74-15 log (100/0.772)=42.3 dB;said plurality of twisted pairs are arranged in said conductor core such that a first twisted pair generally opposes a second twisted pair and such that a third twisted pair generally opposes a fourth twisted pair;said first twisted pair has a twist length in the range of 0.59 to 0.63 inches;said second twisted pair has a twist length in the range of 0.53 to 0.57 inches;said third twisted pair has a twist length in the range of 0.67 to 0.71 inches; andsaid fourth twisted pair has a twist length in the range of 0.76 to 0.80 inches.