Electromagnetic energy transmission and detection apparatus
First Claim
1. An electromagnetic transmission and detection apparatus for transmitting a high intensity electromagnetic field and detecting the presence of a low intensity electromagnetic field emanating from an external source despite the presence of said high intensity electromagnetic field, comprising:
- a support means;
means for generating a first electrical signal for use in creating said high intensity electromagnetic field;
a transmitter coil affixed to said support means for receiving said first electrical signal and transmitting said high intensity electromagnetic field, said transmitter coil including one or more conductive windings circumscribing a substantially polygonal volume of space having a central axis, said transmitter coil being adapted to generate a magnetic flux field within said volume;
first and second receiver coils disposed within said volume of space at significantly separated points and adapted to have linking relationships with portions of said flux field, said first and second receiver coils being electrically connected to each other in a differential circuit relationship such that the magnitude of electrical signals induced in said first and second receiver coils by electromagnetic energy transmitted by said transmitter coil are substantially equal and opposite to each other, whereby electromagnetic energy generated by said external source and passing through at least one of said first and second receiver coils will induce an electrical signal of greater magnitude in one receiver coil than will be induced in the other receiver coil and cause a current to flow in said differential circuit which corresponds to the energy generated by said external source; and
means responsive to said current flowing in said differential circuit and operative to indicate a measure of the energy generated by said external source.
5 Assignments
0 Petitions
Accused Products
Abstract
An electromagnetic transmission and detection apparatus comprising a transmission coil (20) for producing a high intensity electromagnetic field including one or more conductive windings (24) circumscribing a substantially polygonal volume of space having a central axis, and first and second receiver coils (22) disposed within the polygonal volume of space for receiving a low-intensity electromagnetic field transmitted from an external source. The receiver coils (22) are co-planar with the transmitter coil (20) and are disposed within the polygonal volume of the transmitter coil at positions which are polygonally, diametrical opposed to one another. The receiver coils (22) are electrically connected to each other in a differential circuit relationship such that the magnitude of electrical signals induced in the receiver coils (22) by uniform electromagnetic energy are substantially equal and opposite to one another. The differential circuit is operative to substract the electrical signals induced in the receiver coils and output a differential output signal, which is at a minimum when the two receiver coils receive approximately equal quantities of energy and is at a maximum when one of the receiver coils receives more electromagnetic energy from the external source than the other receiver coil. A display device (19) receives the differential output signal and displays a measure of the identification signal when the differential output signal is at a maximum.
110 Citations
32 Claims
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1. An electromagnetic transmission and detection apparatus for transmitting a high intensity electromagnetic field and detecting the presence of a low intensity electromagnetic field emanating from an external source despite the presence of said high intensity electromagnetic field, comprising:
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a support means; means for generating a first electrical signal for use in creating said high intensity electromagnetic field; a transmitter coil affixed to said support means for receiving said first electrical signal and transmitting said high intensity electromagnetic field, said transmitter coil including one or more conductive windings circumscribing a substantially polygonal volume of space having a central axis, said transmitter coil being adapted to generate a magnetic flux field within said volume; first and second receiver coils disposed within said volume of space at significantly separated points and adapted to have linking relationships with portions of said flux field, said first and second receiver coils being electrically connected to each other in a differential circuit relationship such that the magnitude of electrical signals induced in said first and second receiver coils by electromagnetic energy transmitted by said transmitter coil are substantially equal and opposite to each other, whereby electromagnetic energy generated by said external source and passing through at least one of said first and second receiver coils will induce an electrical signal of greater magnitude in one receiver coil than will be induced in the other receiver coil and cause a current to flow in said differential circuit which corresponds to the energy generated by said external source; and means responsive to said current flowing in said differential circuit and operative to indicate a measure of the energy generated by said external source. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An electromagnetic transmission and detection apparatus for transmitting a high intensity electromagnetic field and detecting the presence of a low intensity electromagnetic field emanating from an external source despite the presence of said high intensity electromagnetic field, comprising:
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a structural support means; means for generating a first electrical signal for use in creating said high intensity electromagnetic field; a transmitter coil affixed to said support means for receiving said first electrical signal and transmitting said high intensity electromagnetic field, said transmitter coil including one or more conductive windings circumscribing a substantially polygonal volume of space having a central axis, said transmitter coil being adapted to generate a magnetic flux field within said volume; a first receiver coil including one or more conductive windings circumscribing a first substantially polygonal volume of space having a first central axis; a second receiver coil including one or more conductive windings circumscribing a second substantially polygonal volume of space having a second central axis, said first and second receiver coils disposed within said volume of space of said transmitter coil at significantly separated points and adapted to have linking relationships with portions of said flux field, said first and second receiver coils being electrically connected to each other in a differential circuit relationship such that the magnitude of electrical signals induced in said first and second receiver coils by electromagnetic energy transmitted by said transmitter coil are substantially equal and opposite to each other, whereby electromagnetic energy generated by said external source and passing through at least one of said first and second receiver coils will induce an electrical signal of greater magnitude in one receiver coil than will be induced in the other receiver coil and cause a current to flow in said differential circuit which corresponds to the energy generated by said external source; and means responsive to said current flowing in said differential circuit and operative to indicate a measure of the energy generated by said external source. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. An electromagnetic transmission and detection apparatus for transmitting a high intensity electromagnetic field to a remotely located identification transponder responsive to said high intensity electromagnetic field and operative to transmit a low intensity electromagnetic field including a modulated identification signal, and for detecting the modulated identification signal transmitted by the transponder despite the presence of the high intensity electromagnetic field, comprising:
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a structural support means; means for generating a first electrical signal for use in creating said high intensity electromagnetic field; a transmitter coil affixed to said support means for receiving said first electrical signal and transmitting said high intensity electromagnetic field, said transmitter coil including one or more conductive windings circumscribing a substantially polygonal volume of space having a central axis, said transmitter coil being adapted to generate a magnetic flux field within said volume; first and second receiver coils disposed within said volume of space at significantly separated points and adapted to have linking relationships with portions of said flux field, said first and second receiver coils being electrically connected to each other in a differential circuit relationship such that the magnitude of electrical signals induced in said first and second receiver coils by electromagnetic energy transmitted by said transmitter coil are substantially equal and opposite to each other, whereby electromagnetic energy generated by said external source and passing through at least one of said first and second receiver coils will induce an electrical signal of greater magnitude in one receiver coil than will be induced in the other receiver coil and cause a current to flow in said differential circuit which corresponds to said modulated identification signal transmitted by said transponder; and means responsive to said modulated identification signal and operative to display the content of said modulated identification signal. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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Specification