A wide variety of different types of cables are utilized to transmit power and/or communications signals. In certain types of cables, it is desirable to provide separation for internal cable components. For example, certain cables make use of multiple twisted pairs of conductors to communicate signals. In each pair, the wires are twisted together in a helical fashion to form a balanced transmission line. When twisted pairs are placed in close proximity, such as within the core of a cable, electrical energy may be transferred from one pair of the cable to another pair. Such energy transfer between pairs is undesirable and is referred to as crosstalk. Crosstalk causes interference to the information being transmitted through the twisted pairs and can reduce the data transmission rate and cause an increase in bit rate error. Interlinking typically occurs when two adjacent twisted pairs are pressed together, and interlinking can lead to an increase in crosstalk among the wires of adjacent twisted pairs.
In order to improve crosstalk performance, separators (also referred to as separation fillers, fillers, interior supports, or splines) have been inserted into many conventional cables. Each twisted pair may be twisted to a different twist length or “lay length” in order to control interference associated with signal energy coupling between or among the pairs, including through the separator. The materials of the separator and the insulation material for the twisted pairs affect this interference. However, materials offering improved electrical performance, such as fluorinated ethylene propylene, typically have higher costs. Attempts have been made to reduce high costs materials by forming a separator from foamed materials. However, foamed materials can often become soft and may crush, for example, during processing and/or cable installation. This crushing changes separation distances between adjacent sets of twisted pairs and negatively affects crosstalk and electrical performance. Accordingly, there is an opportunity for improved separators that reduce the usage of high costs materials while maintaining desired electrical performance characteristics. Additionally, there is an opportunity for improved separators including a first subset of solid prongs or fins and a second subset of foamed prongs or fins.
USPTO Backgrounds
USPTO Backgrounds