Temperature compensated coaxial cable isolator

Claim 2

A temperature compensated coaxial isolator for coupling television signals while blocking low frequency power currents comprising: an outer ground conductor having an interruption therein; capacitive signal coupling means and EMI absorption means in the interruption; a plurality of individual capacitive elements in said capacitive signal coupling means; and said individual capacitive elements having temperature coefficients selected to exhibit a capacitance substantially in the range of 3.8 to 5 nanofarads over a temperature variation from about 0 degrees Centigrade to +45 degrees Centigrade.

Claim 3

The isolator of claim 1 wherein there are three capacitive elements, each of substantially annular disc configuration, with conductive surfaces connected in said interruption between isolated portions of said outer ground conductor.

Claim 4

The isolator of claim 2 wherein said EMI absorption means includes annular disc-shaped ferrites interposed between adjacent ones of said capacitive elements.

Claim 5

The isolator of claim 3 wherein said outer ground conductor includes a first tubular element of small diameter engaging the inner one of said conductive surfaces of said capacitive elements and a second tubular element of larger diameter engaging the outer one of said conductive surfaces of said capacitive elements.

Claim 6

The isolator of claim 4 wherein said capacitive elements exhibit peaks in their respective temperature coefficient curves at substantially 5 degrees Centigrade, 25 degrees Centigrade and 45 degrees Centigrade.

Claim 7

A temperature compensated coaxial cable isolator for coupling television signals while blocking DC and low frequency power currents comprising: an outer ground conductor having first and second portions that are electrically isolated by a gap; three ceramic capacitive elements and two interleaved ferrite EMI absorption elements positioned in said gap; each said capacitive element having a temperature coefficient characteristic selected to cooperate with the temperature coefficient characteristics of said other two capacitive elements to produce a capacitance of no less than 3.8 nanofarads and no more than 5.0 nanofarads over temperatures from substantially 0 degrees Centigrade to +45 degrees Centigrade, said capacitive elements and said ferrite elements having a generally tubular configuration with the inner and outer surfaces thereof being connected electrically to said first and said second portions respectively.

Claim 8

A temperature compensated coaxial cable isolator for coupling television signals while blocking DC and low frequency power currents comprising: an outer ground conductor having first and second portions that are electrically isolated by a gap; three ceramic capacitive elements and two interleaved ferrite EMI absorption elements positioned in said gap; each said capacitive element having a temperature coefficient characteristic selected to cooperate with the temperature coefficient characteristics of said other two capacitive elements to produce a capacitance of no less than 3.8 nanofarads and no more than 5.0 nanofarads over temperatures from substantially 0 degrees Centigrade to +45 degrees Centigrade, said capacitive elements and said ferrite elements having a generally tubular configuration with the inner and outer surfaces thereof being connected electrically to said first and said second portions respectively.