Skew adjusted data cable
AssigneeBelden CDT Networking, Inc.
InventorWilliam T. Clark
Life of this patent
Estimating the term…
Abstract
A twisted pair cable wherein characteristics of the twisted pairs, such as twist lay, insulation thickness, characteristic impedance, etc. are selected so as to achieve minimal skew between the twisted pairs. In some examples, insulation materials may be varied among the twisted pairs and composite insulations may be used for one or more pairs in a cable.
Claims6
A cable having a specified characteristic impedance comprising:
- a plurality of twisted pairs of insulated conductors designated into a first group of twisted pairs and a second group of twisted pairs;
- wherein each twisted pair designated into the first group of twisted pairs has a first twist lay, a first insulation thickness and a first nominal impedance;
- wherein each twisted pair designated into the second group of twisted pairs has a second twist lay, a second insulation thickness and a second nominal impedance;
- and
- wherein a first combination of the first twist lay and the first insulation thickness, and a second combination of the second twist lay and the second insulation thickness are selected such that a difference between the first nominal impedance and the second nominal impedance is greater than about 2 Ohms and less than about 15 Ohms, and the cable has a skew of less than approximately 25 ns per 100 m.
A method of manufacturing a cable comprising a plurality of twisted pairs of insulated conductors that are designated into two groups wherein each twisted pair designated into the first group of twisted pairs has a first twist lay, a first insulation material and a first insulation thickness and wherein each twisted pair designated into the second group of twisted pairs has a second twist lay, a second insulation material and a second insulation thickness, the method comprising:
- selecting a combination of the first twist lay, the first insulation material and the first insulation thickness such that the twisted pairs designated into the first group have a first nominal impedance;
- and
- selecting a combination of the second twist lay, the second insulation material and the second insulation thickness such that the twisted pairs designated into the second group have a second nominal impedance that is at least 2 Ohms greater than the first nominal impedance and such that a skew between the twisted pairs of the first group and the twisted pairs of the second group is less than about 25 ns per 100 m.
A cable comprising:
- a plurality of twisted pairs of insulated conductors designated into a first group of twisted pairs and a second group of twisted pairs;
- wherein each twisted pair designated into the first group of twisted pairs has a first insulation material having a first dielectric constant, a first twist lay, a first insulation thickness and a first nominal impedance;
- wherein each twisted pair designated into the second group of twisted pairs has a second insulation material having a second dielectric constant, a second twist lay, a second insulation thickness and a second nominal impedance;
- wherein the second insulation material comprises a first layer having a third dielectric constant and a second layer having a fourth dielectric constant such that the second dielectric constant is an effective dielectric constant of a combination of the first and second layers;
- and
- wherein a first combination of the first twist lay and the first insulation thickness, and a second combination of the second twist lay and the second insulation thickness are selected such that a difference between the first nominal impedance and the second nominal impedance is greater than about 2 Ohms.
Dependencies are inferred from the claim text.