Externally and internally shielded double-layered flat cable assembly

DETAILED DESCRIPTION OF THE INVENTION The invention provides a cable having two rows of primary conductors which are insulated with a low dielectric constant material.
An outer integrated conductive shield is then applied and formed around the insulated primary conductors.
An outer insulating jacket is then applied.
The two rows of insulated primary conductors are separated by an inner conductive shielding material which is preferably perforated at spaced intervals or is conductive mesh, which is usually made by slitting a conductive sheet at intervals, then stretching the sheet in the direction opposite to the direction of slitting to form a mesh.
The gaps created thereby allow bonding of insulation layers through the openings in the perforated sheet or mesh.
This type of construction provides a cable that will have controlled impedance, transmit high fidelity electronic signals, and have separable layers for installation in high density 0.
050 inch pitch insulation displacement connectors.
The center and outer shield material provide individual line conductor electrical isolation for high-speed single-ended digital pulses or analog signals.
For differentially-driven or balanced pair driven signals, the center shield material could be replaced by a non-conductive separator.
The outer shields provide pair-to-pair electrical isolation.
The manufacturing processes for the cable are based on utilization as the insulation of sintered or unsintered full-density or expanded polytetrafluoroethylene (PTFE) and other low-dielectric constant fluorocarbon polymer tapes combined with cabling and sintering processes.
A low dielectric constant insulation material, such as the above, expanded PTFE for example, surrounds copper conductors of 28-30 AWG size, for example.
The insulation is applied by typical tape-wrap or extrusion processes to give an insulated primary conductor.
The insulated primary conductors are cabled into a flat ribbon cable with low dielectric constant insulative material, being laid parallel to each other and optionally on a controlled dimensional pitch