Two port magnetoelastic delay line

Claim 2

A two port magnetoelastic delay line as specified in claim 1 wherein said first and second conductors are substantially colinear, each extending from the center of said polished face and in substantially opposite directions along a common axis to the perimeter of said polished face, whereby said conductors traverse the maximum bias field magnitude variation across the polished face of said magnetic insulator material.

Claim 3

A two port magnetoelastic delay line as specified in claim 3 in which the magnetic insulator material is a sample of single crystal yttrium iron garnet (YIG).

Claim 4

A two port magnetoelastic delay line comprising: a sample of single crystal yttrium iron garnet (YIG) having a polished face; input means for receiving a high frequency signal which is to be delayed; first shielded coupling means for coupling electromagnetic energy to the YIG material representative of said high frequency signal for launching a magnetostatic wave in said YIG material, including a first conductor responsive to said high frequency signal and having a portion of its length contiguous with the polished face of the YIG material and a shielding member having a surface area substantially larger than the surface area of said portion of the first conductor for confining the electromagnetic fields associated with current flow in said first conductor; means for subjecting the YIG material to a spatially varying d-c magnetic bias field whose magnitude increases along a longitudinal axis from the polished face into the YIG material for causing the wavelength of said magnetostatic waves to decrease as they propagate away from the polished face and whose magnitude also increases radially from the interior to the exterior of the YIG material along a cross section of the YIG material; and a second shielded coupling means for coupling electromagnetic energy from said YIG material to produce an output signal representative of the high frequency signal coupled to said first conductor delayed by a predetermined amount, including a second conductor having a portion of its length contiguous to the polished face of the YIG material outside the region of the polished face highly excited by current flow in said first conductor and shielded from said first conductor by a shielding meMber having a surface area substantially larger than the surface area of said portion of the second conductor for confining the electromagnetic fields associated with current flow in said second conductor, said first and second conductors also being arranged substantially colinear, each extending from substantially the center of the end face in opposite directions along a common axis to the perimeter of said end face, and separated by a small gap at their respective terminations near the center of the end face so as to traverse the maximum bias field magnitude variation across the end face of the YIG material and provide maximum bandwidth performance.

Claim 5

A two port magnetoelastic delay line comprising: a sample of single crystal yttrium iron garnet (YIG) having a polished face; input means for receiving a high frequency signal having a predetermined range of frequencies, which is to be delayed, said input means including a first transmission line means having a first grounded conductor and a first ungrounded conductor; utilization load means including a second transmission line having a second grounded conductor and a second ungrounded conductor for translating a high frequency signal representative of the supplied high frequency signal delayed by a predetermined amount; a block of conductive material having a substantially flat face adjacent and parallel to the polished face of the YIG material and having said first and second grounded conductors arranged substantially colinear on and connected to said conductive material; means for subjecting the YIG material to a spatially varying d-c magnetic bias field whose magnitude increases along a longitudinal axis from the polished face into the YIG material and increases radially from the interior of the YIG material to the exterior of the material within a cross section of the YIG material; a first thin conductor positioned adjacent to said flat face and oriented so that the magnetic field traversed by the first conductor increases continuously along the length of said first conductor, isolated from the flat face by a layer of dielectric material, and coupled at one end to the ungrounded conductor of said first transmission line and coupled at the other end to the block of conductive material, for coupling electromagnetic energy to the YIG material as a result of high frequency current flow in the portion of said first conductor coextensive with said flat face; and a second thin conductor positioned adjacent to said flat face and oriented so that the magnetic field traversed by said second conductor increases continuously along the length of said second conductor, isolated from the block of conductive material along said flat face by a layer of dielectric material, and coupled at one end to the ungrounded conductor of said second transmission line and coupled at the other end to the block of conductive material, for producing a current flow in said second conductor representative of the high frequency signal coupled to said first conductor delayed by a predetermined amount.

Claim 6

A two port magnetoelastic delay line as specified in claim 6 wherein said first and second conductors each extend from substantially the center of the end face of said YIG material to the perimeter of said end face and are separated by a small gap at the point of their respective connections to the block of conductive material at the center of said end face so that said conductors traverse the maximum number of bias field magnitude variations across the end face of said YIG material to provide the maximum bandwidth performance.

Claim 7

A two port magnetoelastic delay line comprising: a sample of single crystal yttrium iron garnet (YIG) having a polished face; input means for receiving a high frequency signal having a predetermined range of frequencies which are to be delayed, said input means including a first transmission line means having a first grounded conductor and a first ungrounDed conductor; utilization load means including a second transmission line having a second grounded conductor and a second ungrounded conductor for translating a high frequency signal representative of the supplied high frequency signal delayed by a predetermined amount; a block of conductive material having a substantially flat face contiguous with the polished face of the YIG material and having a narrow groove extending across the polished face of the YIG material, said groove having a width which is less than 0.03 times the shortest free-space wavelength of said predetermined frequencies, and having said first and second grounded conductors arranged substantially colinear on and connected to said block of conductive material; means for subjecting the YIG material to a spatially varying D-C magnetic bias field whose magnitude increases along a longitudinal axis from the polished face into the YIG material and increases radially from the interior of the YIG material to the exterior of the material within a cross section of the YIG material; a first thin conductor positioned along the length of said groove from the center of said polished face to one end of the groove so that the magnetic field traversed by the first conductor increases continuously along the length of said first conductor, isolated from said conductive material along the length of said groove and connected at the center of the groove to the block of conductive material, for coupling electromagnetic energy to the YIG material as a result of high frequency current flow in the portion of said first conductor coextensive with said groove while causing substantially all the return current associated with the current flow in said first conductor to be shielded from the YIG material; and a second thin conductor positioned along the length of said groove from the center of said polished face to the other end of said groove so that the magnetic field traversed by said second conductor increases continuously along the length of said second conductor, isolated from said conductive material along the length of the groove, and coupled at the one end of said groove to said second ungrounded conductor and connected at the center of the groove to the block of conductive material, for producing a current flow in said second conductor representative of the high frequency signal coupled to said first conductor delayed by a predetermined amount while causing substantially all the return currents associated with current flow in said second conductor to be shielded from the YIG material.

Claim 8

A two port magnetoelastic delay line as specified in claim 8 wherein said first and second conductors each extend from substantially the center of said groove to the perimeter of said end face and are separated by a small gap at the point of their connection to the block of conductive material at the center of said groove so that said conductors traverse the maximum number of bias field magnitude variations on the end face of said YIG material and provide the maximum bandwidth performance.

Claim 9

A two port magnetoelastic delay line as specified in claim 9 in which said gap between said first and second conductors is 5 mils, the width of said groove is less than one-eighth of an inch, the width of said first and second conductors is less than 0.010 inch, and in which said first and second conductors are isolated from the block of conductive material along the length of said groove by dielectric material positioned in said groove between said conductors and the block of conductive material.

Claim 10

A two port magnetoelastic delay line as specified in claim 10 in which the YIG material is oriented in the magnetic bias field to minimize the insertion loss and to minimize the spurious delay signals.

Claim 11

A two port magnetoelastic delay line comprising: a sample of single crystal yttrium iron garnet (YIG) having a polished face; input means for receiving a high freQuency signal having a predetermined range of frequencies, which is to be delayed, said input means including a first transmission line means having a first grounded conductor and a first ungrounded conductor; utilization load means including a second transmission line having a second grounded conductor and a second ungrounded conductor for translating a high frequency signal representative of the supplied high frequency signal delayed by a predetermined amount; a thin layer of conductive material contiguous to the polished face of the YIG material and having first and second narrow apertures separated by a portion of the conductive material at the center of said polished face, each aperture having a width less than 0.03 times the shortest free space wavelength of said predetermined frequencies and having said first and second grounded conductors connected to the side of the conductive material opposite the YIG material at the center of the polished face; means for subjecting the YIG material to a spatially varying d-c magnetic bias field whose magnitude increases along a longitudinal axis from the polished face into the YIG material and whose magnitude increases radially from the interior of the YIG material to the exterior of the material within a cross section of the YIG material; a first thin conductor shielded from the YIG material by the thin layer of conductive material except for a portion of the wire which traverses said first aperture transversed to its width, and having a width which is substantially less than the width of said aperture, said wire coupled at one end to the ungrounded conductor of said first transmission line and at the opposite end to the same side of the sheet of conductive material as said first grounded conductor for coupling electromagnetic energy to the YIG material as a result of high frequency current flow in the portion of said conductor which traverses the aperture while causing substantially all the return currents associated with the current flow in said wire to be shielded from the YIG material, said position of said first conductor oriented with respect to said polished face such that the magnetic field traversed by said conductor increases continuously along the length of said portion of said first conductor; and a second thin conductor shielded from the YIG material by the thin layer of conductive material except for a portion of the wire which traverses said second aperture transverse to its width, and having a width which is substantially less than the width of said aperture and being positioned substantially colinear with said first thin conductor, said second thin conductor coupled at one end to the ungrounded conductor of said second transmission line and at the opposite end to the same side of the sheet of conductive material as said second grounded conductor for producing a current flow in said second thin conductor representative of the high frequency signal coupled to said first thin conductor delayed by a predetermined amount while causing substantially all the return currents associated with current flow in said second thin conductor to be shielded from the YIG material, said portion of said first conductor oriented with respect to said polished face such that the magnetic field traversed by said conductor increases continuously along the length of said portion of said first conductor.

Claim 12

A two port magnetoelastic delay line as specified in claim 12 wherein said first and second conductors each extend from substantially the center of the face of the thin layer of conductive material to the perimeter of said face and are separated by a small gap at the point of their connection to the layer of conductive material at the center of the face of the conductive material so that said conductors traverse the maximum number of bias field magnitude variations on the end face of said YIG material and provide the maximum bandwidth performance.

Claim 13

A two port magnetoelastic delay line aS specified in claim 13, in which the width of said first and second apertures is less than one-eighth of an inch and the width of said first and second thin conductors is less than 0.010 inches.