Abstract: It is disclosed an antenna array comprising a number of radiating elements and a supporting elongated flat printed circuit board (PCB) having a substrate and two opposite faces. Each radiating element is attached to the PCB; each radiating element is dipole-like and has a respective axis of symmetry; the axes of symmetry are aligned along a direction parallel to a longitudinal axis of the PCB and lie on a longitudinal plane parallel to a longitudinal center plane of the PCB and located between the opposite faces; the PCB comprises at least one conductive trace on one of the faces, the conductive trace acting as a ground plane; and for each radiating element, the PCB carries a respective feeding line to provide a feeding signal to the radiating element at a feed point located on the PCB and substantially belonging to the axis of symmetry.

Abstract: The present disclosure relates to a phase shifter, which includes: a phase shift circuit board with conductive traces printed thereon; and a phase shift circuit board with conductive traces printed thereon; and a slide device with a first tooth section configured to be driven, wherein movement of the first tooth section drives the slide device to slide on the phase shift circuit board. In addition, the present disclosure further relates to a remote electrical tilt system, which includes an actuator, a transmission mechanism, and at least one phase shifter according to the present disclosure, wherein the actuator is configured to drive the transmission mechanism, and the transmission mechanism engages the first tooth section to drive the slide device to slide on the phase shift circuit board. In addition, the present disclosure also relates to a base station antenna which includes the remote electrical tilt system according to the present disclosure.

Abstract: An autonomous mobile device (AMD) includes a telescoping mast with sensors on top that are connected to a cable running through the mast. An inner section of the mast includes a bobbin that secures cables. The bobbin has a shaft and features that guide cables to helically wind around the shaft. The bobbin reduces stress on the cable as the mast moves. The mast is lifted by a rack that includes a portion with teeth and a portion without. The portion with teeth is driven by a motor. The portion without teeth connects the rack to a spool. The toothless section reduces stress on the toothed portion of the rack as it spools or unspools. The AMD includes a hinge to tilt a display. To securely position the hinge on a shaft, the shaft is spun after assembly so that a push nut cuts a retention groove in the shaft.

Abstract: An FM broadcasting antenna is described having a mast, a pair of forward-facing elements, and a pair of rear-facing elements. The antenna makes use of angles between the antenna elements and the mast, a multi-diameter feed line, a multi-diameter center pin, and mounting points of a strap extending between at least one of the forward-facing elements, at least one of the rear-facing elements and the center pin, for achieving desired broadband and performance characteristics.

Abstract: In-building antenna apparatus and methods for manufacturing and installing the same. In one embodiment, the antenna apparatus includes a radome cover, a lower flange, an antenna housing, a spring-loaded mount apparatus, a signaling interface, and a plurality of spring arms. Each of the spring arms may include at least one tie-down location. Accordingly, when a removable tie is placed around a plurality of tie-down locations, the antenna apparatus resides in an installation configuration; however, when the removable tie is removed from around the plurality of tie-down locations, the antenna apparatus transitions towards a default configuration. The spring arms may also act as a ground plane for the antenna. Spring-loaded mount apparatus as well as methods of manufacturing and installing the aforementioned antenna apparatus are also disclosed.

Abstract: A double-frequency antenna structure with a high degree of electrical isolation between long distance and short distance antennas includes a dielectric substrate having at least two corners and a center area. A first set of antenna arrays is positioned at the corners. A second set of antenna arrays is positioned at the center area. At least one first folded isolation plate is mounted on the dielectric substrate, and positioned between the first set of antenna arrays and the second set of antenna arrays. At least one second folded isolation plate each is mounted on one first folded isolation plate.

Abstract: The present disclosure pertains to an antenna assembly configured to inconspicuously provide mobile communication in rugged or tactical environments. Some embodiments may include: a flexible conductor configured to receive and/or emit electromagnetic radiation; a printed circuit board (PCB) configured to match characteristic impedances; and a connector configured to mate with another connector associated with a radio or amplifier, the PCB being potentially disposed within an interior portion of the connector of the antenna assembly.

Abstract: A dipole arm assembly for a low frequency band radiator of a cellular base station antenna comprising: a central shaft; and at least one barrel having a first end, a second end, and a peripheral wall located between the first end and the second end, where the first end includes an end wall provided with an engagement portion, and the barrel is engaged with the central shaft through the engagement portion and disposed about the central shaft.

Abstract: An ablation device includes a feedline including an inner conductor having a distal end, an outer conductor coaxially disposed around the inner conductor, and a dielectric material disposed therebetween, an elongated electrically-conductive member longitudinally disposed at the distal end of the inner conductor and having a proximal end, a first balun structure disposed over a first portion of the outer conductor and positioned so that a distal end of the first balun structure is located at a first distance from the proximal end of the electrically-conductive member and a second balun structure disposed over a second portion of the outer conductor and positioned so that a distal end of the second balun structure is located at a second distance from the proximal end of the electrically-conductive member.

Abstract: A pneumatic tire has a passive transponder incorporated therein that allows communication with a radio-frequency reader located outside the pneumatic tire. The passive transponder includes at least one radiating antenna and is embedded in an electrically insulating elastomeric blend to form a patch. The patch extends axially between an axially inner end of a carcass ply of the pneumatic tire and an inner surface of the pneumatic tire. The patch also extends radially at a distance between a bead toe of the pneumatic tire and a radially outer end of a bead core of the pneumatic tire.

Abstract: A cable assembly including a first connector, a second connector, and a cable is disclosed that routes power, and/or information between devices. The cable includes a first group of one or more conductors that are mechanically connected to the first connector and the second connector to route power and/or one or more wired information communications between the devices. The cable also includes a second group of one or more that is mechanically connected to the first connector to provide one or more wireless information communications between the first device and the second device or a third device which is not mechanically connected to the cable assembly.

Abstract: An antenna array comprising: four dipole antennas configured to function together as a directional, near vertical incidence skywave (NVIS) antenna with reduced side lobes, wherein each dipole antenna comprises two conductive elements and a feed point disposed between the two conductive elements, wherein the conductive elements of each of the four dipole antennas are disposed in an x-y plane of an x-y-z mutually orthogonal axes coordinate system, and wherein the conductive elements are substantially parallel with the x-axis and the x-y plane is substantially parallel with a ground plane; and wherein the feed points of the four dipole antennas are positioned on the x-y plane at approximately (x, 0), (?x, 0), (0, y), and (0, ?y), and wherein the x-y plane is separated from the ground plane by a distance h that is less than or equal to 1/10 the wavelength (?) of an operating frequency.

Abstract: A synthesized-beam transceiver system steers a beam of a two-dimensional antenna array by activating a first subset of antenna elements to orient the beam in a first direction and subsequently activating a second subset of the antenna elements to orient the beam in a different direction. The system also electrically connects antenna elements that are inactive, not in the first subset, or not in the second subset to a reference potential of the array.

Abstract: The present invention relates to an antenna system including at least two antenna modules operable for transmitting and/or receiving radiation in certain common frequency band. The at least two antenna modules are collinearly arranged along a common axis so as to provide low gain along the axis, and are spaced apart from one another along this axis by a distance of at least a few nominal wavelengths of the common frequency band. Each two locally adjacent antenna modules of the at least two antenna modules operate with substantially mutually orthogonal polarizations of radiation, thereby suppressing electromagnetic coupling between the antenna modules in the common frequency band.

Abstract: A reduced profile leaky-wave antenna and methods for manufacture therefor can include an inner conductor and an outer conductor. The outer conductor can be arranged in a coaxial relationship around the inner conductor to define an annular waveguide. A helical aperture can be formed in the outer conductor, to establish a leaky-wave antenna configuration. The helical aperture can have a helical pitch, which can be chosen according to the desired physical length of the antenna. For monopole reduced profile leaky-wave antennas, a metallic disk can optionally be placed the distal end of the antenna. For dipole reduced profile leaky-wave antenna embodiments, a metallic disk can be place at both ends of the antenna. The devices and methods of the present invention have the added advantage of allowing for the same feed structure to be used for both monopole antennas and dipole antennas.

Abstract: A cable assembly including a first connector, a second connector, and a cable is disclosed that routes power, and/or information between devices. The cable includes a first group of one or more conductors that are mechanically connected to the first connector and the second connector to route power and/or one or more wired information communications between the devices. The cable also includes a second group of one or more that is mechanically connected to the first connector to provide one or more wireless information communications between the first device and the second device or a third device which is not mechanically connected to the cable assembly.

Abstract: An apparatus has an improved antenna pattern for a cross dipole antenna. Such antennas desirably have an omnidirectional antenna pattern. Conventional cross dipole antennas exhibit nulls in their antenna patterns, which can cause antennas to deviate from a standard or specification. Applicant recognized and confirmed that the connection of a coaxial cable to the antenna arms is a cause of the nulls in the antenna pattern, and has devised techniques disclosed herein to compensate or cancel the effects of the connection. In one embodiment, the arms of the cross dipole antenna that are coupled to a center conductor of the coaxial cable remain of conventional length, but the arms of the cross dipole antenna that are coupled to a shield of the coaxial cable are lengthened by a fraction of the radius of the outer diameter of the coaxial cable.

Abstract: A system for heating a hydrocarbon resource in a subterranean formation having a wellbore extending therein, the system including a radio frequency (RF) source, an RF antenna configured to be positioned within the wellbore, a transmission line coupling the RF source and the RF antenna, and a compound current choke surrounding the transmission line. The compound current choke includes a plurality of spaced apart, overlapping, electrically conductive sleeves. Each of the plurality of spaced apart, overlapping, electrically conductive sleeves may have a first open end and a second closed end coupled to the transmission line.

Abstract: An antenna system and related method are disclosed for an electrically small antenna of variable geometry capable of a harmonically pure resonant radiation pattern over a broadband coverage of frequency selection. One geometrical embodiment comprises a multiple loop antenna system is configured to radiate a switched signal via the multiple antenna elements to inhibit transmission of any of the harmonics of the signal. An additional geometrical embodiment comprises a cylindrical shell with one or more interior center conductors to overcome radiation resistance and radiate a signal pattern of desirable toroidal shape free from undesirable harmonics.

Abstract: The apparatus includes an RF antenna assembly to be positioned within a wellbore and coupled to an RF source. The RF antenna assembly includes a first tubular dipole element having opposing proximal and distal ends, an RF transmission line extending through the proximal end of the first tubular dipole element and including an inner conductor, an outer conductor, and a dielectric therebetween. The inner conductor extends outwardly beyond the distal end of the first tubular dipole element. The outer conductor is coupled to the distal end of the first tubular dipole element. The RF antenna assembly includes a second tubular dipole element having opposing proximal and distal ends, with the proximal end being adjacent the distal end of the first tubular dipole element and being coupled to the inner conductor, and a tubular balun.

Abstract: A synthesized-beam transceiver system steers a beam of a two-dimensional antenna array by activating a first subset of antenna elements to orient the beam in a first direction and subsequently activating a second subset of the antenna elements to orient the beam in a different direction. The system also electrically connects antenna elements that are inactive, not in the first subset, or not in the second subset to a reference potential of the array.

Abstract: An unsymmetrical dipole antenna includes a grounding element, a radiating element, and a feed-in wire. The grounding element includes a first short side metal plane and a first long side metal plane. The radiating element includes a second short side metal plane and a second long side metal plane. The feed-in wire includes a metal wire, coupled to the second short side metal plane for transmitting a feed-in signal; an insulation layer, covering the metal wire; a metal weave, covering the insulation layer, having one terminal coupled to the first short side metal plane of the grounding element, and another terminal coupled to a system ground of the wireless communication device; and a protective layer, covering the metal weave. A size of the grounding element and a size of the radiating element are irrelative.

Abstract: A dipole antenna assembly may include a first tubular dipole element and a coaxial antenna feed extending through a proximal end of the first tubular dipole element. The coaxial antenna feed may have an inner conductor, an outer conductor, and a dielectric therebetween. The inner conductor may extend outwardly beyond a distal end of the first tubular dipole element. The outer conductor may be coupled to the distal end of the first tubular dipole element. The dipole antenna assembly may further include a second tubular dipole element with a proximal end being adjacent the distal end of the first tubular dipole element, and being coupled to the inner conductor. The second tubular dipole element may include first and second tubular segments and an electrical conductor extending through the first and second tubular sections and being coupled thereto at both the proximal and distal ends.

Abstract: A nichrome resistive element is used in a closed electrical circuit to form an antenna.

Abstract: A low-profile broadband multiple antenna, comprises: a dipole arranged in the top part of said antenna, said dipole comprising at least one first top antenna element connected to the core of a multi-axial cable comprising a core and n sheaths and the bottom individual element of which is connected to the first sheath adjacent to the core, a connection device positioned between a top element of a dipole and the bottom element of said dipole the top element is connected to the sheath of index (k?1) of the multi-axial cable after the assembly comprising the core and the sheaths of index (1 to k?1) has been wound in Q turns around a magnetic core and the bottom element of the dipole is connected to the sheath of index k, and said connection device comprises at least one single-wire winding of P turns on the same magnetic core linking said bottom element of said dipole to the sheath of index (k?1), at the point corresponding to the start of the winding in order to provide the broadband impedance matching and the p

Abstract: A multimode antenna structure is provided for transmitting and receiving electromagnetic signals in a communications device. The communications device includes circuitry for processing signals communicated to and from the antenna structure. The antenna structure includes a plurality of antenna ports for coupling to the circuitry; a plurality of antenna elements, each operatively coupled to a different one of the antenna ports; and a plurality of connecting elements. The connecting elements each electrically connect neighboring antenna elements such that the antenna elements and the connecting elements are arranged about the periphery of the antenna structure and form a single radiating structure.

Abstract: An electromagnetic wave radiation coaxial cable and a communication system using the same. The electromagnetic wave radiation coaxial cable includes an inner conductor which is formed of a conductor and extends along a cable axis, an insulator covering the inner conductor, and an outer conductor spirally wound around the insulator in a single winding at a predetermined pitch to provide a gap from which a part of the insulator is exposed. Following formula is established: ? r - 1 < ? P < ? r + 1 when ? is a wavelength of a radio frequency signal to be transmitted or received, ?r is a relative dielectric constant of the insulator at the wavelength ?, and P is a winding pitch of the outer conductor along the direction of the cable axis.

Abstract: A multi-band whip antenna having a 30 MHz to 2 GHz bandwidth and an L-band dipole has its coverage extended up to 6 GHz by eliminating nulls and reducing VSWR problems that are cured through the utilization of a sleeve over the feedpoint of the L-band antenna. Chokes in the form of sleeves are provided at either end of the L-band dipole to shorten the L-band antenna for preventing reverse polarity currents at the L-band antenna feedpoint, with the antenna further including the use of double shielded meanderlines to provide improved performance between 410-512 MHz and in which a capacitance sleeve is added at the bottom of the L-band antenna to effectively elongate the antenna below the L-band to permit operation below 700 MHz.

Abstract: A dipole antenna includes a circuit board with a first side and a second side, at least one dipole disposed on the circuit board comprising an upper half and a lower half, a microstrip transmission line disposed on the circuit board coupled to at least one of the upper half and lower half of the at least one dipole, and a choke element disposed on the circuit board. The choke element and the lower half of the at least one dipole form an open slot trap with a high impedance point.

Abstract: An compact manpack format antenna operating over a broad bandwidth. In one arrangement, the antenna is formed from a set of five hollow cylindrical conductive elements. Several cylinders provide, for example, a VHF/UHF radiator section and other cylinders form an L-band radiator section. A bottom leg of the L-band section operates as part of the VHF/UHF section via coupling between that lower L-band leg and the VHF/UHF section. This coupling arrangement reduces the required overall physical length of the antenna.

Abstract: Provided is a small monopole antenna, which can generate a plurality of resonant frequencies, have a high antenna efficiency, and be easily installed. The antenna includes a first antenna element formed of a coaxial cable; a second antenna element sealing the first antenna element and sharing a feed point with the first antenna element; and a feeder cable for feeding electric power to the feed point. This antenna is applied as a small antenna.

Abstract: An apparatus has an improved antenna pattern for a cross dipole antenna. Such antennas desirably have an omnidirectional antenna pattern. Conventional cross dipole antennas exhibit nulls in their antenna patterns, which can cause antennas to deviate from a standard or specification. Applicant recognized and confirmed that the connection of a coaxial cable to the antenna arms is a cause of the nulls in the antenna pattern, and has devised techniques disclosed herein to compensate or cancel the effects of the connection. In one embodiment, the arms of the cross dipole antenna that are coupled to a center conductor of the coaxial cable remain of conventional length, but the arms of the cross dipole antenna that are coupled to a shield of the coaxial cable are lengthened by a fraction of the radius of the outer diameter of the coaxial cable.

Abstract: An end-fed sleeve dipole is provided herein with improved impedance match and increased bandwidth by incorporating a ¾-wavelength transformer in the antenna design. The ¾-wavelength transformer is compatible with a number of different choking schemes, including but not limited to, a single ¼-wave choke sleeve, a single ¼-wave choke sleeve with additional ferrite beads, and two or more ¼-wave choke sleeves with or without ferrite beads. In some embodiments, one or more shunt resonators may be used to provide additional impedance compensation.

Abstract: A nichrome resistive element is used in a closed electrical circuit to form an antenna.

Abstract: A three-dimensional dual-band antenna including a first radiation portion, a second radiation portion, a connection portion, an impedance matching portion and a feeding portion is provided. The second radiation portion is located under the radiation portion and parallel with the first radiation portion. The connection portion is connected to the first side of the first radiation portion and extended downward vertically, for connecting the first radiation portion and the second radiation portion. The impedance matching portion is connected to a second side of the first radiation portion and extended downward vertically. The first side and the second side are opposite. The feeding portion is connected to the second side and extended downward vertically. The feeding portion receives a feeding signal. The first and the second radiation portion are operated at the first and the second bandwidth respectively, wherein the second bandwidth is in higher frequency than the first bandwidth.

Abstract: Disclosed is a log periodic antenna and a manufacturing method thereof. In the log periodic antenna, antenna elements are attached to an antenna body to thereby simplify a structure of the antenna, the antenna can be manufactured in various designs without restriction to the configuration of the antenna, and the number of contacting points between the antenna element and a feeder is minimized to thereby simplify the manufacturing process. By the antenna, it is possible to produce the log periodic antenna of the simple structure and of various designs without the restriction to the antenna configuration by attaching the signal pattern and ground pattern to the pattern receiving surface.

Abstract: An accessory system (202, 402, 502) for a portable radio transceiver (200) includes an accessory device (206) which includes a speaker and/or a microphone disposed external of the portable radio transceiver. A cable (204) containing two or more conductors is provided for operatively connecting the accessory device to the portable radio transceiver. At least one antenna (210, 212) for the portable radio transceiver is integrated within the cable. When the accessory system is used with a multi-band portable radio transceiver, two or more antennas can be included in the cable, each optimized for operation on a particular RF frequency band.

Abstract: A multi-feed dipole antenna and method. Provides a volumetrically efficient antenna with wide radiation pattern bandwidth and wide impedance bandwidth that are relatively independent. Driving the antenna at multiple locations provides for a half wavelength dipole antenna with a wider frequency range than any other known fat dipole of similar volume. The apparatus is constructed from brass or any other suitable metal without requiring dielectric loading and without requiring direct coupling on the outside of the tubes. The apparatus utilizes a parasitic center tube with two end tubes that are driven by a collinearly mounted metal rod that is driven from the midpoint. Insulators hold the parasitic tube to the end tubes. The parasitic tube allows for induced currents to flow on the surface of the tube which allow for operation of the dipole over a wide frequency range.

Abstract: An apparatus has an improved antenna pattern for a cross dipole antenna. Such antennas desirably have an omnidirectional antenna pattern. Conventional cross dipole antennas exhibit nulls in their antenna patterns, which can cause antennas to deviate from a standard or specification. Applicant recognized and confirmed that the connection of a coaxial cable to the antenna arms is a cause of the nulls in the antenna pattern, and has devised techniques disclosed herein to compensate or cancel the effects of the connection. In one embodiment, the arms of the cross dipole antenna that are coupled to a center conductor of the coaxial cable remain of conventional length, but the arms of the cross dipole antenna that are coupled to a shield of the coaxial cable are lengthened by a fraction of the radius of the outer diameter of the coaxial cable.

Abstract: Antenna elements operable to radiate different patterns are provided. A particular apparatus includes a first antenna element having a plurality of radiating elements. Each of the radiating elements includes a first member having a first end and a second end. The first end is coupled to an antenna interface and the second end extends a length of the first member from the first end. Each of the radiating elements further includes a second member having a third end and a fourth end. The third end is electrically coupled to the first member at a point partway along the length of the first member. The fourth end extends away from the first member. When a first radiating element is radiating in the presence of a second radiating element, a null is generated in a radiation pattern of the first radiating element.

Abstract: The present invention relates to a small cobra antenna that has a high performance as an antenna gain, and minimizes the effect of the length of the coaxial wire. An antenna element and a coaxial wire are connected to a junction that is a feeding point. The antenna element has a length corresponding to the frequency of a broadcast wave to be received. Further, a ferrite core is positioned at a location a length identical to the length of the antenna element away from the junction. The coaxial wire is wound around the ferrite core about once to three times. A high frequency interrupting part for interrupting the high-frequency current from the coaxial wire is provided at the front side of a connecter of a receiver to which the other end of the coaxial wire is connected.

Abstract: A compact antenna for transmitting or receiving a radio frequency signal includes a metal wire extending from a first location to a second location, an insulation layer extending from the first location to a third location, for covering a portion of the metal wire from the first location to the third location, a metal weave extending from the first location to a fourth location, for covering a portion of the insulation layer from the first location to the fourth location, and a grounding metal tube extending from a fifth location to the third location, for covering a portion of the metal weave from the fifth location to the fourth location, and covering a portion of the insulation layer from the fourth location to the third location.

Abstract: An apparatus has an improved antenna pattern for a cross dipole antenna. Such antennas desirably have an omnidirectional antenna pattern. Conventional cross dipole antennas exhibit nulls in their antenna patterns, which can cause antennas to deviate from a standard or specification. Applicant recognized and confirmed that the connection of a coaxial cable to the antenna arms is a cause of the nulls in the antenna pattern, and has devised techniques disclosed herein to compensate or cancel the effects of the connection. In one embodiment, the arms of the cross dipole antenna that are coupled to a center conductor of the coaxial cable remain of conventional length, but the arms of the cross dipole antenna that are coupled to a shield of the coaxial cable are lengthened by a fraction of the radius of the outer diameter of the coaxial cable.

Abstract: A multi-band antenna assembly that is operable to receive and/or transmit signals at one or more frequencies generally includes at least two radiating elements, a transmission line coupled to each of the at least two radiating elements, and a tunable match resonator coupled to the transmission line. The tunable match resonator is operable to vary input impedance of a signal received and/or transmitted by the antenna assembly by changing an electrical field within the tunable match resonator.

Abstract: An end-fed sleeve dipole is provided herein with improved impedance match and increased bandwidth by incorporating a ¾-wavelength transformer in the antenna design. The ¾-wavelength transformer is compatible with a number of different choking schemes, including but not limited to, a single ¼-wave choke sleeve, a single ¼-wave choke sleeve with additional ferrite beads, and two or more ¼-wave choke sleeves with or without ferrite beads. In some embodiments, one or more shunt resonators may be used to provide additional impedance compensation.

Abstract: A broadband antenna system is disclosed. The antenna system relates to a modified conical structure, wherein the feed region of the cone is cut away to form a hollow “coneless” cylinder, and the distribution of one or more tapered feed points around the circumference of the cylinder allows a plurality of feed lines, cables, piping, or other structures to be run through the center of the antenna without interfering with the performance of the antenna system. The invention further relates to a stacked broadband antenna system wherein additional coneless elements, as well as other types of antennas or devices, may be stacked collinearly on, or disposed coaxially to, the cylindrical antenna structure, and fed, powered or operated via the plurality of feed lines, cables, piping or other structures. The overall system may thus provide a wide range of transmitting, receiving, sensing and other capabilities.

Abstract: A low-profile broadband multiple antenna, comprises: a dipole arranged in the top part of said antenna, said dipole comprising at least one first top antenna element connected to the core of a multi-axial cable comprising a core and n sheaths and the bottom individual element of which is connected to the first sheath adjacent to the core, a connection device positioned between a top element of a dipole and the bottom element of said dipole the top element is connected to the sheath of index (k?1) of the multi-axial cable after the assembly comprising the core and the sheaths of index (1 to k?1) has been wound in Q turns around a magnetic core and the bottom element of the dipole is connected to the sheath of index k, and said connection device comprises at least one single-wire winding of P turns on the same magnetic core linking said bottom element of said dipole to the sheath of index (k?1), at the point corresponding to the start of the winding in order to provide the broadband impedance matching and the p

Abstract: A multi-band whip antenna having a 30 MHz to 2 GHz bandwidth and an L-band dipole has its coverage extended up to 6 GHz by eliminating nulls and reducing VSWR problems that are cured through the utilization of a sleeve over the feedpoint of the L-band antenna. Chokes in the form of sleeves are provided at either end of the L-band dipole to shorten the L-band antenna for preventing reverse polarity currents at the L-band antenna feedpoint, with the antenna further including the use of double shielded meanderlines to provide improved performance between 410-512 MHz and in which a capacitance sleeve is added at the bottom of the L-band antenna to effectively elongate the antenna below the L-band to permit operation below 700 MHz.

Abstract: A multi-band antenna comprising a conductive structure and a plurality of current probes coupled around the conductive structure is disclosed. An existing antenna capable of generating H fields having a first signal line is converted into a multi-signal line antenna with increased frequency capabilities, by mounting a first current probe having a designated frequency range about a periphery of the existing antenna; coupling a second signal line to the first current probe; and performing at least one of transmitting and receiving via at least one of the first and second signal lines, wherein the mounting of the first current probe to the existing antenna improves a voltage standing wave ratio (VSWR) of the existing antenna and the second signal line operates as an independent signal line for signal reception/transmission within the designated frequency range.

Abstract: The apparatus includes an RF antenna assembly to be positioned within a wellbore and coupled to an RF source. The RF antenna assembly includes a first tubular dipole element having opposing proximal and distal ends, an RF transmission line extending through the proximal end of the first tubular dipole element and including an inner conductor, an outer conductor, and a dielectric therebetween. The inner conductor extends outwardly beyond the distal end of the first tubular dipole element. The outer conductor is coupled to the distal end of the first tubular dipole element. The RF antenna assembly includes a second tubular dipole element having opposing proximal and distal ends, with the proximal end being adjacent the distal end of the first tubular dipole element and being coupled to the inner conductor, and a tubular balun.