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An antenna operable to transmit or receive radio frequency signals at a specified frequency, the antenna comprising a first printed circuit board comprising a first loop of conductive material having a capacitance and an inductance, the capacitance and the inductance forming a circuit being resonant

An antenna operable to transmit or receive radio frequency signals at a specified frequency, the antenna comprising a first printed circuit board comprising a first loop of conductive material having a capacitance and an inductance, the capacitance and the inductance forming a circuit being resonant at the specified frequency; and a second printed circuit board comprising a second loop of conductive material having two ends adapted to be electrically coupled to an electronic circuit, the second loop being substantially only magnetically coupled to the first loop and electrically insulated from the first loop; the antenna for use with a device for controlling the power delivered to an electrical load, further wherein the first loop of the conductive material comprises a break and the capacitance includes a capacitor bridging the break; wherein the first loop comprises a first metal layer on a first side of the first printed circuit board and a second metal layer on a second, opposite side of the first printed circuit board, the first and second layers being electrically connected to each other and wherein the break is provided in one of layers.

대표청구항 ▼

What is claimed is: 1. An antenna operable to transmit or receive radio frequency signals at a specified frequency, the antenna comprising: a first printed circuit board comprising a first loop of conductive material having a capacitance and an inductance, the capacitance and the inductance forming

What is claimed is: 1. An antenna operable to transmit or receive radio frequency signals at a specified frequency, the antenna comprising: a first printed circuit board comprising a first loop of conductive material having a capacitance and an inductance, the capacitance and the inductance forming a circuit being resonant at the specified frequency; and a second printed circuit board comprising a second loop of conductive material having two ends adapted to be electrically coupled to an electronic circuit, the second loop being substantially only magnetically coupled to said first loop and electrically insulated from the first loop; said antenna for use with a device for controlling the power delivered to an electrical load, further wherein the first loop of the conductive material comprises a break and the capacitance includes a capacitor bridging the break; wherein the first loop comprises a first metal layer on a first side of the first printed circuit board and a second metal layer on a second, opposite side of the first printed circuit board, the first and second layers being electrically connected to each other and wherein the break is provided in one of said layers. 2. The antenna of claim 1, wherein the second loop is substantially at line voltage potential. 3. The antenna of claim 1, wherein said capacitor is trimmable to adjust said given frequency. 4. The antenna of claim 1, wherein the first and second layers are electrically coupled by via holes through the first printed circuit board provided at opposite ends of the printed circuit board. 5. The antenna of claim 1, wherein an electrical current flows in said first loop in a plane perpendicular to a plane of the first printed circuit board. 6. The antenna of claim 1, wherein electrical current flows in said first loop along a main loop axis of the first printed circuit board. 7. The antenna of claim 4, wherein electrical current flows in said first loop along a main loop axis of the first printed circuit board through each of the metal layers of the first printed circuit board and through the via holes of the first printed circuit board. 8. The antenna of claim 1, further comprising an inductance trimmer provided on said first printed circuit board for adjusting the specified frequency. 9. The antenna of claim 8, wherein the inductance trimmer comprises at least one cut made in at least one of said metal layers. 10. The antenna of claim 1, wherein partially trimming away part of one of said first and second metal layers changes the inductance of the first printed circuit board thereby to adjust said given frequency. 11. The antenna of claim 1, further comprising interdigitated fingers in at least one of the metal layers for trimming the capacitance of the first printed circuit board thereby adjusting the specified frequency. 12. The antenna of claim 11, wherein the at least one capacitor is coupled across said break on the first metal layer on the first side of said first printed circuit board and the interdigitated fingers are disposed on the second side of the first printed circuit board. 13. The antenna of claim 12, wherein the interdigitated fingers comprise first and second sets of fingers, the first set of fingers being coupled to the first metal layer of the first side of the first printed circuit board and the second set of fingers being coupled to the second metal layer on the second side of the first printed circuit board. 14. The antenna of claim 13, wherein the first set of fingers are coupled to the first metal layer on the first side of the first printed circuit board by a via hole. 15. The antenna of claim 1, further comprising at least one conductive region on one of said first and second sides of the first printed circuit board separated from said one of said first and second metal layers by a gap surrounding the at least one conductive region, the at least one conductive region being electrically coupled to the other of said first and second metal layers thereby forming a capacitance, said capacitance being trimmable by adjusting at least one dimension of said at least one conductive region. 16. The antenna of claim 15, wherein said at least one conductive region is coupled to the other of said first and second metal layers by a via hole. 17. The antenna of claim 1, further comprising a plurality of capacitors connected across the break on one of the first and second sides of the first printed circuit board, each capacitor being coupled by a via hole to the metal layer on the other of the first and second sides, there being provided a respective trace coupled to each capacitor connecting the capacitor to the metal layers on the other of the first and second sides, at least one of the traces being capable of being cut to trim the capacitance thereby to adjust said given frequency. 18. The antenna of claim 17, wherein the plurality of capacitors are on the first side of the first printed circuit board and respective via holes connect the capacitors to the second side of the first printed circuit board, and further wherein the traces for each capacitor are disposed on one or both sides of the first printed circuit board and connect the via holes to at least one of the first and second metal layers. 19. The antenna of claim 1, further comprising via holes connecting the first and second metal layers, and wherein respective traces on at least one side of the first printed circuit board connect the via holes to at least one of the metal layers, the traces being capable of being cut to trim the inductance of the first loop, thereby to adjust the given frequency. 20. The antenna of claim 1, wherein said second printed circuit board comprises two layers of insulating material with said second loop sandwiched between said two layers. 21. The antenna of claim 1, wherein one of said two ends of said second loop is coupled to said electronic circuit by a DC blocking capacitor. 22. The antenna of claim 1, further comprising shielding material covering a portion of said second loop below the plane of said yoke. 23. The antenna of claim 1, further comprising a plurality of second loops connected in parallel. 24. The antenna of claim 23, wherein the plurality of second loops are sandwiched between layers of insulating material. 25. The antenna of claim 1, wherein the first loop radiates an RF signal at the specified frequency that is substantially isotropic.