Flexible coaxial cable apparatus and method

A method of forming a coaxial cable, comprising the steps of:

• providing a multilayer configuration comprised of an inner layer of adjacent signal traces which are formed in a layer of dielectric material, said layer of dielectric material being sandwiched between a pair of outer ground plane layers;
• removing portions of the outer ground plane layers and dielectric material to expose a first, second, third and fourth of said adjacent signal traces, while leaving covered a fifth of said adjacent signal traces, said second and third signal traces lying between said first and fourth signal traces, and said fifth signal trace forming a conducting signal trace lying between said second and third signal traces;
• forming a 360-degree signal return line by connecting said second and third signal traces to said outer ground plane layers to produce a 360-degree conductive enclosure around said conducting signal trace whereby said conducting signal trace is isolated from its 360-degree signal return line by a layer of said dielectric material;
• and
• shielding said 360-degree signal return line, said shielding step comprising connecting said first and fourth signal traces to an additional conductive layer.

A cable for propagating electrical signals, comprising:

• a plurality of means for conducting an electrical signal, each electrical signal conducting means being surrounded by dielectric material;
• a plurality of signal return conductor means each surrounding a respective one of said electrical signal conducting means and being spaced apart therefrom by said dielectric material;
• a layer of dielectric material surrounding each said signal return conductor means;
• and
• means surrounding each said layer of dielectric material for shielding each of said signal return conductor means, said shielding means including shared conductor means joining adjacent ones of said layers of dielectric material to form a unitary cable of said plurality of electrical signal conducting means and their surrounding signal return conductor means.

A cable for propagating electrical signals, comprising:

• a plurality of means for conducting an electrical signal, each electrical signal conducting means being surrounded by dielectric material;
• a plurality of signal return conductor means each surrounding a respective one of said electrical signal conducting means and being spaced apart therefrom by said dielectric material, each said signal return conductor means comprising:
• a lower planar conductor element;
• a first vertical conductor element connected to the lower planar conducting element;
• a first signal trace connected to said first vertical conductor element;
• an upper planar conductor element;
• a second vertical conductor element connecting said upper planar conductor element to the first signal trace;
• a second signal trace;
• a third vertical conductor element electrically connecting the upper planar conductor element to said second signal trace;
• and
• a fourth vertical conductor element electrically connecting the second signal trace to the lower planar conductor element;
• a layer of dielectric material surrounding each said signal return conductor means;
• and
• means surrounding each said layer of dielectric material for shielding each of said signal return conductor means.

A cable for propagating electrical signals, comprising:

• a plurality of means for conducting an electrical signal, each electrical signal conducting means being surrounded by dielectric material;
• a plurality of signal return conductor means each surrounding a respective one of said electrical signal conducting means and being spaced apart therefrom by said dielectric material;
• a layer of dielectric material surrounding each said signal return conductor means;
• and
• means surrounding each said layer of dielectric material for surrounding each of said signal return conductor means, said means for shielding comprising:
• a bottom planar conductor element;
• a third signal trace;
• a first vertical shield conductor element electrically connecting the bottom planar conductor element to the third signal trace;
• a top planar conductor element;
• a second vertical shield conductor element electrically connecting the top planar conductor element to the third signal trace;
• a fourth signal trace;
• a third vertical conductor element electrically connecting the top planar conductor to the fourth signal trace;
• and
• a fourth vertical conductor element electrically connecting the fourth signal trace to the bottom planar conductor element.