초록 ▼

An antenna for generating radiation includes a primary E-field generating circuit and a secondary E-field generating circuit. The primary E-field generating circuit generates a primary E-field in response to a source RF signal being applied to the antenna. The secondary E-field generating circuit ge

An antenna for generating radiation includes a primary E-field generating circuit and a secondary E-field generating circuit. The primary E-field generating circuit generates a primary E-field in response to a source RF signal being applied to the antenna. The secondary E-field generating circuit generates a secondary E-Field, disposed apart from the primary E-field, in response to the source RF signal and develops an H-field that is in time phase with the primary E-field. This causes the antenna to develop a radiation resistance as an indication of radiation.

대표청구항 ▼

1. An antenna system, for use with a signal cable having a signal lead and a common lead, comprising:a. a first elongated dipole element; b. a second elongated dipole element coupled to the common lead and spaced apart from the first elongated dipole element; and c. an inductor, spaced apart from th

1. An antenna system, for use with a signal cable having a signal lead and a common lead, comprising:a. a first elongated dipole element; b. a second elongated dipole element coupled to the common lead and spaced apart from the first elongated dipole element; and c. an inductor, spaced apart from the first elongated dipole element and the second elongated dipole element, and substantially coaxial with the first elongated dipole element and the second elongated dipole element, the inductor having a inductor proximal end and an inductor distal end, the inductor proximal end being electrically coupled to the signal lead and the inductor distal end being electrically coupled to the first elongated dipole element. 2. The antenna system of claim 1, wherein the second elongated dipole element is placed between the first elongated dipole element and the inductor so as to be coaxial with the first elongated dipole element and the inductor.3. The antenna system of claim 1, further comprising a tube having an exterior surface, wherein the first elongated dipole element, the second elongated dipole element and the inductor are disposed about the exterior surface of the tube.4. The antenna system of claim 3, wherein the tube comprises an insulator.5. The antenna system of claim 4, wherein the insulator comprises polyvinyl chloride.6. The antenna system of claim 1, further comprising a moveable contact that is electrically coupled to the signal lead and that electrically couples the signal lead to the inductor, the moveable contact being capable of coupling the signal lead to the inductor at a selected position of the inductor.7. The antenna system of claim 1, wherein the first elongated dipole element comprises a conductive cylinder.8. The antenna system of claim 1, wherein the second elongated dipole element comprises a conductive cylinder.9. The antenna system of claim 1, wherein the inductor comprises a conductive coil.10. The antenna system of claim 1, wherein the first elongated dipole element has a first diameter, the second elongated dipole element has a second diameter and the inductor each has a third diameter, and wherein the first diameter, the second diameter and the third diameter are essentially equal.11. An antenna for use with a signal cable having a signal lead and a common lead, comprising:a. an insulating elongated support member; b. a first cylindrical conductor disposed about a first portion of the support member, the first cylindrical conductor having a proximal end and an opposite distal end; c. a second cylindrical conductor disposed about a second portion of the support member and spaced apart from the first cylindrical member, the second cylindrical conductor having a proximal end and an opposite distal end, the proximal end in electrical communication with the common lead; d. a conductive coil coiled about the elongated support member, spaced apart from and substantially coaxial with the first cylindrical conductor and the second cylindrical conductor, the conductive coil having a proximal end and an opposite distal end, the proximal end being in electrical communication with the signal lead and the distal end being in electrical communication with the proximal end of the first cylindrical conductor; and e. a moveable contact that is electrically coupled to the signal lead and that electrically couples the signal lead to the conductive coil, the moveable contact being capable of coupling the signal lead to the conductive coil at a selected position of the inductor so as to make the antenna tunable with respect to resonant frequency. 12. The antenna of claim 11, wherein the insulating elongated support member comprises a plastic tube.13. The antenna of claim 11, wherein the first cylindrical conductor comprises metal foil.14. The antenna of claim 11, wherein the second cylindrical conductor comprises metal foil.15. A communications antenna for both transmitting and receiving in association with a communications system through a feed line having a high side and a ground, comprising:a. two dipole elements that are short relative to a predetermined operating wavelength and that have a diameter so as to have a predetermined capacity therebetween; b. an inductance, having a source end, disposed proximal to the two dipole elements, a first end of the inductance being electrically coupled to a first one of the two dipole elements; a second one of the two dipole elements being electrically coupled to the feed line, the high side of the feed line being connected to an end of the inductance opposite the source end, so that the predetermined capacity is resonated with an inductance and so that at a resonant frequency a large voltage forming a primary E field is developed between the two dipole elements and at the source end of the inductance a source voltage is 90 degrees delayed relative to the primary E field and so that the source voltage forms a secondary E field between the source end of the inductance and the two dipole elements and so that the secondary E field causes a displacement current to flow in a natural capacity of the space between the source end of the inductance and the dipole elements, such that the displacement current is advanced 90 degrees through the capacity so as to be in phase with the primary E field and develop a magnetic (H) field that surrounds the primary E field.