Microwave transmission line and devices using multiple coplanar conductors

Claim 2

A transmission line for electromagnetic energy comprising: a dielectric substrate having a predetermined dielectric constant; first, second and third coplanar strip-like conductors having predetermined widths adjacent to one surface of said dielectric substrate, said first conductor having one edge separated from an adjacent edge of said second conductor by a first predetermined gap and an edge opposite said one edge separated from an adjacent edge of said third conductor by a second predetermined gap, said second conductor being arranged to be at a first R.F. potential relative to said first conductor and said third conductor being arranged to be at a second different R.F. potential relative to said first conductor in the presence of said electromagnetic energy, said first, second and third conductor widths, said dielectric constant, and said first and second predetermined gaps being arranged to form said transmission line, and means for coupling said electromagnetic energy at frequency f to said transmission line, whereby electric fields of said electromagnetic energy are substantially confined within said dielectric substrate between said first and second conductors and between said first and third conductors and simultaneously between said second and third conductors.

Claim 3

A transmission line according to claim 1, wherein said dielectric substrate has a thickness which is more than four times b1, where b1 is the distance from the center line of said first conductor to said adjacent edge of said second conductor.

Claim 4

A transmission line according to claim 1, wherein said electromagnetic energy coupling means is a coaxial connector having an outer conductor connected to one end of said second strip-like conductor and an inner conductor connected to one end of said first strip-like conductor closest to said one end of said second conductor.

Claim 5

In combination: a dielectric substrate having a predetermined dielectric constant; first, second and third coplanar strip-like conductors having predetermined widths adjacent to one surface of said dielectric substrate, said first conductor having one edge separated from an adjacent edge of said second conductor by a first predetermined gap and an edge opposite said one edge separated from an adjacent edge of said third conductor by a second predetermined gap, said second conductor being arranged to be at a first R.F. potential relative to said first conductor and said third conductor being arranged to be at a second different R.F. potential relative to said first conductor in the presence of said electromagnetic energy, said first, second and third conductor widths, said dielectric constant, and said first and second predetermined gaps being arranged to form said transmission line; and means for coupling said electromagnetic energy at frequency f to said transmission line, whereby said electromagnetic energy having a first magnetic field component with a first magnitude is confined on said one substrate surface between said first and second strip-like conductors and a second magnetic field component having a magnitude greater than said first magnitude, said second magnetic field component being confined on said one substrate surface between said first and third strip-like conductors.

Claim 6

In combination: a dielectric substrate having a predetermined dielectric constant; first, second and third coplanar strip-like conductors having predetermined widths adjacent to one surface of said dielectric substrate, said first conductor having one edge separated from an adjacent edge of said second conductor by a first predetermined gap and an edge opposite said one edge separated from an adjacent edge of said third conductor by a second predetermined gap, said second conductor being arranged to be at a first R.F. potential relative to said first conductor and said third conductor being arranged to be at a second different R.F. potential relative to said first conductor in the presence of said electromagnetic energy, said first, second and third conductor widths, said dielectric constant, and said first and second predetermined gaps being arranged to form said transmission line; and means for coupling said electromagnetic energy at frequency f to said transmission line, whereby said electromagnetic energy having a first magnetic field component with a first magnitude is confined on said one substrate surface between said first and second strip-like conductors and a second magnetic field component having a magnitude greater than said first magnitude, said second magnetic field component being confined on said one substrate surface between said first and third strip-like conductors.

Claim 7

An electromagnetic energy directional coupler operative over a desired band of frequencies comprising: a dielectric substrate having a predetermined dielectric constant; first, second and third coplanar strip-like conductors each having input and output ends and predetermined widths and lengths adjacent to one surface of said dielectric substrate, said first conductor having one edge separated from an adjacent edge of said second conductor over said predetermined length by a first predetermined gap and an edge opposite said one edge separated from an adjacent edge of said third conductor over said predetermined length by a second predetermined gap, said second conductor being arranged to be at a first R.F. potential relative to said first conductor and said third conductor being arranged to be at a second different R.F. potential relative to said first conductor in the presence of said electromagnetic energy, said first, second and third conductor widths and lengths, said dielectric constant, and said first and second predetermined gaps being arranged to form said transmission line; means for applying said electromagnetic energy between said first conductor input end and said second conductor input end to confine electric fields of said electromagnetic energy substantially within said dielectric substrate between said first and second conductors and between said first and third conductors and simultaneously between said second and third conductors; means for coupling out said electromagnetic energy between said first conductor input end and said third conductor input end; means for directly transmitting out said electromagnetic energy between said first conductor output end and said second conductor output end; and means for terminating said electromagnetic energy between said first conductor oUtput end and said third conductor output end.

Claim 8

An electromagnetic energy directional coupler operative over a desired band of frequencies comprising: a dielectric substrate having a predetermined dielectric constant; first, second and third coplanar strip-like conductors each having input and output ends and predetermined widths and lengths adjacent to one surface of said dielectric substrate, said first conductor having one edge separated from an adjacent edge of said second conductor over said predetermined length by a first predetermined gap and an edge opposite said one edge separated from an adjacent edge of said third conductor over said predetermined length by a second predetermined gap, said second conductor being arranged to be at a first R.F. potential relative to said first conductor and said third conductor being arranged to be at a second different R.F. potential relative to said first conductor in the presence of said electromagnetic energy, said first, second and third conductor widths and lengths, said dielectric constant, and said first and second predetermined gaps being arranged to form said transmission line; means for applying said electromagnetic energy between said first conductor input end and said second conductor input end to confine electric fields of said electromagnetic energy substantially within said dielectric substrate between said first and second conductors and between said first and third conductors and simultaneously between said second and third conductors; means for coupling out said electromagnetic energy between said first conductor input end and said third conductor input end; means for directly transmitting out said electromagnetic energy between said first conductor output end and said second conductor output end; and means for terminating said electromagnetic energy between said first conductor oUtput end and said third conductor output end.

Claim 9

A directional coupler according to claim 5 wherein each of said first, second and third conductor predetermined lengths from said input to output ends is substantially an odd multiple of lambda /4, where lambda is the wavelength at the center frequency of said desired band of frequencies.

Claim 10

A directional coupler according to claim 5, wherein said second conductor width is equal to said third conductor width and said first predetermined gap is equal to said second predetermined gap.

Claim 11

A transmission line for electromagnetic energy comprising: a dielectric substrate having a predetermined dielectric constant; first, second and third coplanar strip-like conductors having predetermined widths adjacent to one surface of said dielectric substrate, said first conductor having one edge separated from an adjacent edge of said second conductor by a first predetermined gap and an edge opposite said one edge separated from an edge of said third conductor by a second predetermined gap; means for coupling said electromagnetic energy at frequency f to said transmission line; and means for providing said second conductor with a first R.F. potential relative to said first conductor and said third conductor with a second different R.F. potential relative to said first conductor in the presence of said electromagnetic energy, whereby electric fields of said electromagnetic energy are substantially confined within said dielectric substrate between said first and second conductors and between said first and third conductors and simultaneously between said second and third conductors.

Claim 12

A transmission line for electromagnetic energy comprising: a dielectric substrate having a predetermined dielectric constant; first, second and third coplanar strip-like conductors having predetermined widths adjacent to one surface of said dielectric substrate, said first conductor having one edge separated from an adjacent edge of said second conductor by a first predetermined gap and an edge opposite said one edge separated from an edge of said third conductor by a second predetermined gap; means for coupling said electromagnetic energy at frequency f to said transmission line; and means for providing said second conductor with a first R.F. potential relative to said first conductor and said third conductor with a second different R.F. potential relative to said first conductor in the presence of said electromagnetic energy, whereby electric fields of said electromagnetic energy are substantially confined within said dielectric substrate between said first and second conductors and between said first and third conductors and simultaneously between said second and third conductors.