Abstract: A utility meter has an internal antenna for transmitting data. The antenna is positioned between the radome of the utility meter and its front surface. The antenna comprises dipole radiator that is generally curved to the shape of the meter housing. The dipole radiator comprises a dielectric substrate carrying two asymmetric curved radiating metallic sheets, each forming a portion of the dipole, which combined extend about 135° of the circumference of the utility meter. A balun feed is connected to the metallic sheets and a transmission line is coupled to a transmitter.

Abstract: A utility meter has an internal antenna for transmitting data. The antenna is positioned between the radome of the utility meter and its front surface. The antenna comprises dipole radiator that is generally curved to the shape of the meter housing. The dipole radiator comprises a dielectric substrate carrying two asymmetric curved radiating metallic sheets, each forming a portion of the dipole, which combined extend about 135° of the circumference of the utility meter. A balun feed is connected to the metallic sheets and a transmission line is coupled to a transmitter.

Abstract: An antenna comprising a reflective surface; and an array of dipole antenna elements disposed adjacent to the reflective surface. Each antenna element has a pair of arms which together define a dipole axis, and the dipole axis is tilted at an acute angle with respect to the reflective surface. The pair of arms may be dipole arms, or may be Yagi director arms. In some embodiments the dipole axis is tilted at an acute angle with respect to a feed axis. In some embodiments the antenna element comprises a feed portion defining a feed axis; and the feed portion has a mounting portion which is tilted at an acute angle with respect to the feed axis.

Abstract: A balanced dipole antenna, comprising: a left dipole arm having a center end, a right dipole arm having a center end, a coaxial cable having an outer conductor and a single inner conductor and a top end electrically located between the center ends of the left and right dipole arms, a left stub coupling the left dipole arm and the coaxial cable, and a right stub coupling the right dipole arm and the coaxial cable, wherein the inner conductor of the coaxial cable is connected to one of the left and right dipole arms, and the outer conductor of the coaxial cable is connected to the other of the left and right dipole arms.

Abstract: A dual polarized broadband base station antenna for wireless communication systems is disclosed. The present invention employs a dual polarized boxed arrangement radiation element with high isolation between polarization channels. Plural radiating elements project outwardly from the surface of a ground plane. The antenna elements are paired dipoles.

Abstract: A polymorphic antenna, including a metallic template configurable in at least first and second possible different three-dimensional shapes, the antenna, when configured in the at least first and second different three-dimensional shapes, having a common antenna feed point, a common balun coupled to the common antenna feed point; and a common dipole coupled to the common antenna feed point and to the common balun. The antenna operates in a common frequency band when configured in either of the at least first and second different three-dimensional shapes when fed via the common antenna feed point.

Abstract: A balanced dipole antenna has a coaxial cable connected between a load or source and the left and right dipole arms to substantially eliminate common mode current and radiative coupling between the coaxial cable and the left and right dipole arms. The connection between the source/load coaxial cable and the left and right dipole arms is a symmetric balun having a center branch that is an extension of the source/load coaxial cable, and left and right stubs. When the stubs are segments of coaxial cable, the outer conductors of the left and right stubs of the symmetric balun are respectively coupled to the left and right dipole arms, and one of the inner conductors of the left and right stubs is connected to the inner conductor of the center branch, while the other of the inner conductor of the left and right stubs is connected to the outer conductor of the center branch.

Abstract: An antenna. A base body made of a dielectric material is provide, wherein the base body has a bottom surface and an opposed top surface. A conductive layer of a conductive material is provided on the bottom surface of the base body. Two dipole conductors are provided that form a dipole on the top surface of the base body, wherein the dipole conductors are at least partially spiral shaped and have opposite directions. A balun is provided that has a feed conductor section and two ground conductor sections that are all substantially parallel. The balun receives an unbalanced signal from a feed line, transforms this signal, and provides it to the dipole conductors via the feed and ground conductor sections.

Abstract: A balanced antenna is integrated into a wireless mobile device, such as a laptop computer, for improved antenna reception. The antenna is connected to a radio frequency (RF) interconnection cable. A balun is disposed between the antenna and the cable. By using a balanced antenna, the fraction of the noise produced by the motherboard and display of the wireless mobile device that is captured by the antenna is significantly reduced compared to that captured by an unbalanced antenna, and thus not captured by the antenna.

Abstract: Various embodiments are directed to high isolation antenna design for reducing frequency coexistence interference. In one embodiment, a computing device may comprise a printed circuit board including a first internal antenna and a second internal antenna operating in a common frequency band. At least one of the first internal antenna and the second internal antenna may comprise a balanced antenna coupled to an unbalancing element to suppress surface current on the printed circuit board and reduce frequency coexistence interference between the first internal antenna and the second internal antenna. Other embodiments are described and claimed.

Abstract: A balun used in high-power applications capable of accommodating a transmission line includes a core with a top surface and a bottom surface formed from soft iron material. At least two holes are provided through the core between the top surface and the bottom surface to accommodate at least one winding of the transmission line. For a given amount of core material and transmission line wound through the core, the balun serves to maximize the amount impedance on the outside surface of the transmission line to decrease the amount of electrical flux generated where the transmission line is attached to the transmission lines of an antenna.

Abstract: Described is a dipole which may includes a feed line electrically coupled to a first antenna element; a balun electrically coupled to a second antenna element; and a short assembly slidably coupled to the feed line and the balun to create a short circuit at variable distances along the feed line and the balun.

Abstract: An antenna design, having two symmetrical phased array blade antenna elements which provide improved lateral target coverage with an increased effective radiated power and exhibits smooth null-free bi-directional antenna patterns. Each blade antenna element is coupled to a 180 degrees hybrid divider/combiner by a semi-rigid RF cable. Each blade antenna element is also connected to a sub-resonant choke balun for improved impedance matching and resultant distortion-less antenna patterns.

Abstract: An object of the invention is to provide an adaptor device for a car radio capable of improving the receiving state. The adaptor device 20 for a car radio is connected to a vehicle-mounted antenna connection terminal 12 provided in an FM radio receiver 10 installed within a vehicle room, and includes a signal line inserted between the vehicle-mounted antenna connection terminal 12 and a vehicle-mounted antenna 110; and an in-vehicle antenna 22 branching out from the signal line. A radio wave transmitted from an FM transmitter 40 disposed within the vehicle room via an antenna 42 is received by the radio receiver 10 via the in-vehicle antenna 22.

Abstract: A log-periodic dipole array antenna including a dielectric substrate, and antenna elements, symmetrical microstrip lines and baluns disposed on two corresponding surfaces of the substrate is provided. The antenna elements on each surface are connected to one side of the corresponding symmetrical microstrip line, respectively. The width of at least one antenna element on each surface is broadened gradually outwards from the side of the antenna element, which is connected to the corresponding symmetrical microstrip line. In addition, the baluns are connected to the ends of the corresponding symmetrical microstrip lines, respectively. The antenna elements on one surface are in a mirror-image relation to those on the other surfaces. The log-periodic dipole array antenna features increased broadband with a thin and compact-size, better margin in design to meet different bandwidth requirements.

Abstract: A balanced dipole antenna has a coaxial cable connected between a load or source and the left and right dipole arms to substantially eliminate common mode current and radiative coupling between the coaxial cable and the left and right dipole arms. The connection between the source/load coaxial cable and the left and right dipole arms is a symmetric balun having a center branch that is an extension of the source/load coaxial cable, and left and right stubs. When the stubs are segments of coaxial cable, the outer conductors of the left and right stubs of the symmetric balun are respectively coupled to the left and right dipole arms, and one of the inner conductors of the left and right stubs is connected to the inner conductor of the center branch, while the other of the inner conductor of the left and right stubs is connected to the outer conductor of the center branch.

Abstract: Described is a universal dipole which may include a feed line coupled to a first fitting; a balun coupled to a second fitting; a first variable length antenna element coupled to the first fitting; a second variable length antenna element coupled to the second fitting; a support plate holding the feed line and the balun at a fixed spacing, the support plate including a short circuit path between the feed line and the balun; and a sliding short assembly attachable between the feed line and the balun to create a short circuit at variable distances along the feed line and the balun.

Abstract: A dipole fractal antenna and a method of manufacturing thereof are described. The antenna includes a pair of oppositely directed radiating arms coupled to a feeding terminal and extended therefrom along a central axis in a common plane. At least a portion of each radiating arm has a fractal geometric shape. The antenna also includes at least one pair of electrical shunts configured for connecting at least two points selected within the fractal portion of one radiating arm correspondingly to two points selected within the fractal portion of another radiating arm. The dipole fractal antenna further may comprise a balun arranged at the feeding terminal and configured for coupling the pair of oppositely directed radiating arms to a coaxial cable to provide a balanced feed.

Abstract: The present invention relates to connecting and impedance matching a balanced electrical signal, such as that received by an antenna, with an unbalanced transmission circuit, such as that delivered to an amplifier. A planar circuit board is described that delivers signals having opposite polarization collected by different antenna arms to a location for convenient connection to a twin-lead transmission line. Circuit topologies for the circuit board are described that provide relatively low loss and low cross-coupling. A tapered microstrip balun is also described that includes two conducting microstrips on opposing faces of a dielectric separator. Stepped or tapered microstrips at the balanced input port of the balun provide an impedance transforming section electrically connecting to a mode transducing section, in which one of the microstrips tapers outward to form a substantially wider strip. Appropriate choice of parameters is shown to lead to favorable performance in a compact balun.

Abstract: An antenna (10) having a plurality of unitary dipole antennas (12) formed by folding a stamped piece of sheet metal. Each of the unitary dipole antennas (12) are fed by two stripline feed systems (20, 22). Each of these feed systems are separated above and extend over a groundplane (14) and are separated by an air dielectric to minimize intermodulation (IM). Phase shifters (40, 42, 44) in combination with a downtilt control lever (52) are slidably adjusted beneath the respective dividing portions of the stripline feed system to adjust signal phase and achieve a uniform beam tilt having uniform and balanced side lobes. These stripline feed systems can also be formed from stamped sheet metal and which have distal ends bent 90° upward to couple to the respective dipole antennas (12).

Abstract: A wide band antenna, which has a wide frequency band so that it can be used in a wireless local area network (WLAN) and can be manufactured in a small size at a low cost, is provided. The wide band antenna includes a first antenna unit, a supply cable, a first connector coupler, a second antenna unit, a balun, a stub, and a second connector coupler. A frequency band increases when coupling occurs between the stub and the first antenna unit or the second antenna unit.

Abstract: A effectively balanced dipole antenna is provided comprising an unbalanced microstrip antenna having a transmission line interface and a planar balun connected to the transmission line interface of the antenna. The balun can be coplanar or multi-planar. For example, a coplanar balun includes an unbalanced coplanar transmission line, with a signal line interposed between a pair of coplanar grounds, and a pair of planar stubs plan-wise adjacent the coplanar grounds. The coplanar grounds are connected to the plane stubs with conductive lines proximate to the antenna transmission line interface. A microstrip planar balun includes an unbalanced microstrip signal line, a microstrip ground formed on the dielectric layer underlying the signal line, and a pair of planar stubs, plan-wise adjacent the microstrip ground. The planar stubs can be located on the same dielectric layer as the signal line or the ground. A stripline planar balun is also provided.

Abstract: A balun that includes a first conductor, a second conductor and a third conductor. The first conductor has a length of about one quarter wavelength of a selected center frequency. The first conductor also has a first end connected to a first balanced power amplifier output port. The second conductor has a length of about one quarter wavelength of the selected center frequency. The second conductor also includes a first end connected to a second balanced power amplifier output port and a second end connected a second end of the first conductor. The third conductor has a length of about one quarter wavelength of the selected center frequency. The third conductor has a first end connected to an antenna port and a second end connected to a ground potential.

Abstract: Provided is an antenna system for terrestrial broadcasting. The antenna system has a dipole antenna probe receiving a broadcast signal, a signal amplifier amplifying the received broadcast signal, an antenna matching unit matching impedances between the antenna probe and the signal amplifier, an output matching unit matching impedances between an output signal of the signal amplifier and an input terminal of a broadcast receiver to which the output signal is fed, and a bias extractor converting power received from the broadcast receiver into power needed for driving the signal amplifier and supplying the converted power to the signal amplifier.

Abstract: A plate dipole antenna includes a pair of plates arranged in substantially the same plane or arranged in different planes, with a width to length ratio of one width unit to ten length units or greater. The plate dipole antenna may further include a gain plate.

Abstract: The dipole antenna array is formed by connecting a plurality of dipole antennas, one end of the dipole antenna array has an open stub and a balancing circuit to adjust the width of frequency band, impedance and gain of the antenna array. Each dipole antenna is added on the two ends thereof with antenna loading devices such as a plurality of mini-aperture antennas. The dipole antenna array can have an option to add a reflector on an end thereof.

Abstract: The invention concerns a dipole antenna of reduced size and with improved impedance bandwidth. The antenna is preferably formed on a dielectric substrate having a plurality of regions, each having a characteristic relative permeability and permittivity. First and second dipole radiating element defining conductive paths can be selectively formed on first characteristic regions of the substrate having a first characteristic permeability and first permittivity. A reactive coupling element can be interposed between the dipole radiating elements for reactively coupling the first dipole radiating element to the second dipole radiating element.

Abstract: The present invention provides a planar antenna having a scalable multi-dipole structure for receiving, and transmitting high-frequency signals, including a plurality of opposing layers of conducting strips disposed upon either side of an insulating (dielectric) substrate.

Abstract: An antenna (10) having a plurality of unitary dipole antennas (12) formed by folding a stamped piece of sheet metal. Each of the unitary dipole antennas (12) are fed by two stripline feed systems (20, 22). Each of these feed systems are separated above and extend over a groundplane (14) and are separated by an air dielectric to minimize intermodulation (IM). Phase shifters (40, 42, 44) in combination with a downtilt control lever (52) are slidably adjusted beneath the respective dividing portions of the stripline feed system to adjust signal phase and achieve a uniform beam tilt having uniform and balanced side lobes. These stripline feed systems can also be formed from stamped sheet metal and which have distal ends bent 90° upward to couple to the respective dipole antennas (12).

Abstract: An antenna (10) having a plurality of unitary dipole antennas (12) formed by folding a stamped piece of sheet metal. Each of the unitary dipole antennas (12) are fed by two stripline feed systems (20, 22). Each of these feed systems are separated above and extend over a groundplane (14) and are separated by an air dielectric to minimize intermodulation (IM). Phase shifters (40, 42, 44) in combination with a downtilt control lever (52) are slidably adjusted beneath the respective dividing portions of the stripline feed system to adjust signal phase and achieve a uniform beam tilt having uniform and balanced side lobes. These stripline feed systems can also be formed from stamped sheet metal and which have distal ends bent 90° upward to couple to the respective dipole antennas (12).

Abstract: An antenna system with at least one tunable dipole element with a length adjustable conductive member disposed therein that enables the antenna to be used over a wide range of frequencies. The element is made of two longitudinally aligned, hollow support arms made of non-conductive material. Disposed longitudinally inside each element is a length adjustable conductive member electrically connected at one end. In the preferred embodiment, each conductive member is stored on a spool that is selectively rotated to precisely extend the conductive member into the support arm. The support arms, which may be fixed or adjustable in length, are affixed at one end to a rigid housing. During use, the conductive members are adjusted in length to tune the element to a desired frequency.

Abstract: An antenna formed on a dielectric substrate including at least a first and second dielectric substrate region. One or more antenna-radiating element is formed on the first region of the dielectric substrate and defines a conductive path. Feed circuitry for the antenna can be formed on the second region of the dielectric substrate. The feed circuitry can comprise a balun, an impedance transformer, and/or a feed line. The dielectric substrate in the first region can preferably have a first relative permeability and/or first permittivity different from a second relative permeability and/or a second permittivity of the dielectric substrate of the second region.

Abstract: Matching circuit for radio antenna that functions on a two-frequency band which are spaced approximately at a distance of one octave, wherein the upper band is broad. For instance, the first frequency band may be 890-940 MHz and the other band 1710-2200 MHz. The radiator may be a dipole or a monopole over the earth plane, whose bandwidth is sufficient for the first band. The larger bandwidth for the second band is obtained with a transmission circuit that moves and forms the frequency curve stepwise in the Smith chart. When necessary, the matching circuit includes a broadband Balun transformer in addition to said matching circuit.

Abstract: The present invention provides a metrology antenna system that combines a sleeve dipole antenna having two coaxial input ports with a balancing network. This combination (1) minimizes or eliminates spurious radiation from the balancing network (2) provides for a symmetric pair of feed regions which may be made arbitrarily small, and (3) provides for an essentially perfect impedance match to a broad range of resistive source impedances. The present invention provides a fabrication of arbitrarily small feed regions such that dipoles can be realized at high frequencies at little manufacturing cost.

Abstract: An antenna (10) having a plurality of unitary dipole antennas (12) formed by folding a stamped piece of sheet metal. Each of the unitary dipole antennas (12) are fed by two stripline feed systems (20, 22). Each of these feed systems are separated above and extend over a groundplane (14) and are separated by an air dielectric to minimize intermodulation (IM). Phase shifters (40, 42, 44) in combination with a downtilt control lever (52) are slidably adjusted beneath the respective dividing portions of the stripline feed system to adjust signal phase and achieve a uniform beam tilt having uniform and balanced side lobes. These stripline feed systems can also be formed from stamped sheet metal and which have distal ends bent 90° upward to couple to the respective dipole antennas (12).

Abstract: Disclosed is a portable communication terminal usable at multiple frequencies while being capable of achieving a reduction in specific absorption rate (SAR). The terminal includes two dipole antennas mounted on an antenna printed circuit board (PCB) mounted to a PCB of the terminal and respectively adapted to operate at usable frequencies f1 and f2. A coaxial cable is connected at its end to the dipole antennas, and a cylindrical bazooka type balun (bazooka) for multiple frequencies is fitted around the end of the coaxial cable. The bazooka includes a first dielectric cylinder, a second dielectric cylinder, and a conductor cylinder. The dielectric cylinders are coaxially fitted in the dielectric cylinder. The dielectric cylinders are used for the frequencies f1 and f2 while having electrical lengths corresponding to the frequencies f1 and f2, respectively.

Abstract: A dielectric-loaded antenna for circularly polarized radiation has a generally cylindrical solid dielectric body with a relative dielectric constant greater than 5, upon which body is plated a conductive sleeve encircling the body and a conductive end layer which, together with the body, form an open-ended cavity substantially filled with the ceramic material of the body. The electrical length of the cavity rim is a whole number of guide wavelengths corresponding to the antenna operating frequency less than 5 GHz. A rotating standing wave is excited around the cavity rim by a feeder structure including two helical conductor tracks on the cylindrical surface of the body which are coupled between the cavity rim and a coaxial feeder passing axially through the body.

Abstract: Matching circuit for radio antenna that functions on a two-frequency band which are spaced approximately at a distance of one octave, wherein the upper band is broad. For instance, the first frequency band may be 890-940 MHz and the other band 1710-2200 MHz. The radiator may be a dipole or a monopole over the earth plane, whose bandwidth is sufficient for the first band. The larger bandwidth for the second band is obtained with a transmission circuit that moves and forms the frequency curve stepwise in the Smith chart. When necessary, the matching circuit includes a broadband Balun transformer in addition to said matching circuit.

Abstract: A combination linearly polarized antenna and quadrifilar helix antenna (40) includes a quadrifilar antenna (49) having a first coaxial cable (46) and an antenna with linear polarization (44) external to the quadrifilar antenna and having a second coaxial cable (42). A center conductor of the second coaxial cable is isolated from a center conductor of the first coaxial cable and the first coaxial cable runs substantially concentrically through the antenna with linear polarization.

Abstract: An antenna for use at UHF and upwards has a cylindrical ceramic core with a relative dielectric constant of at least 5. A three-dimensional radiating element structure, including helical antenna elements on the cylindrical surface of the core and connecting radial elements on a distal end face of the core, is formed by conductor tracks plated directly on the core surfaces. At the distal end face, the elements are connected to an axially located feed structure in a plated axial passage of the core. The antenna elements are grounded on a plated sleeve covering a proximal part of the core which, in conjunction with the feeder structure, forms an integral balun for matching to an unbalanced feeder. Since the ceramic core fills the major part of the interior volume defined by the radiating element structure, the antenna is very much smaller than an air-cored antenna.

Abstract: Disclosed is a portable communication terminal usable at multiple frequencies while being capable of achieving a reduction in specific absorption rate (SAR). The terminal includes two dipole antennas mounted on an antenna printed circuit board (PCB) mounted to a PCB of the terminal and respectively adapted to operate at usable frequencies f1 and f2. A coaxial cable is connected at its end to the dipole antennas, and a cylindrical bazooka type balun (bazooka) for multiple frequencies is fitted around the end of the coaxial cable. The bazooka includes a first dielectric cylinder, a second dielectric cylinder, and a conductor cylinder. The dielectric cylinders are coaxially fitted in the dielectric cylinder. The dielectric cylinders are used for the frequencies f1 and f2 while having electrical lengths corresponding to the frequencies f1 and f2, respectively.

Abstract: Antenna elements A1 to A24 of a ring-shaped array antenna are selectively connected to power combiners each with a switch SH1, SH2 and SH3 one after another. When a direct wave and a reflected wave arrive in the directions of the antenna elements A5 and A3, respectively, the antenna elements A2, A5 and A8 in the power combiner SH2 are selected and their received signals are input into a receiver Rr to obtain therefrom an output Sr(2+5+6, f), and the respective antenna elements of the power combiners SH1 and SH3 are sequentially selected and their received signals are input into a receiver Rm to obtain therefrom outputs Sm(1, f), Sm(3, f), . . . . The outputs from the receivers Rr and Rm are caused to interfere with each other in an interferer 11 to detect an interference output to obtain data E(K, L).

Abstract: A UHF antenna has an electrically insulative cylindrical core of a solid material having a relative dielectric constant greater than 5, and a three-dimensional antenna element structure disposed on or adjacent the outer cylindrical surface of the core. The antenna element structure is coupled to a coaxial feeder passing axially through the core. To reduce the effect of unwanted resonant modes associated with the resonant length of the feeder inside the core, the core is spaced from the outer conductor of the feeder by an intervening layer of insulative material having a relative dielectric constant which is much lower that that of the core material.

Abstract: A dipole antenna for use with a mobile subscriber unit in a wireless network communications system. The antenna is fabricated with printed circuit board (PCB) photo-etching techniques for precise control of the printed structure. The dipole antenna includes a planar substrate made of dielectric material. A conductive planar element is layered on one side of the substrate in an upper region of the substrate, and a conductive planar ground patch is layered on the other side of the substrate in a lower region of the substrate. That is, the conductive planar element is stacked above the conductive planar ground patch. A feed strip is connected to the bottom of the conductive planar element, and extends from the element to a bottom edge of the substrate and terminates at a bottom feed point. Typically, the feed point is connected to a transmission line for transmitting signals to and receiving signals from the dipole antenna.

Abstract: Antenna apparatus is comprised of dipole antenna arranged proximate to a surface of metal housing including radio device circuit and having two quarter wavelength elements having opposite end portions being feed points, short-circuit element short-circuiting the quarter wavelength elements, and coaxial feed line having outer conductor and central conductor having one ends connected to the feed points, respectively, and connecting the feed points to radio device circuit. The coaxial feed line is arranged along part of the quarter wavelength element and part of the short-circuit element and branched from central portion of the short-circuit element. The outer conductor is electrically connected to part of the quarter wavelength element and part of the short-circuit element. Currents leaked onto the feed line and flowing through the two quarter wavelength elements are also divided to the short-circuit element.

Abstract: A planar printed circuit antenna (1) comprises a printed circuit board (PCB) (10) mounted on an insulative substrate (100), a plurality of electronic dipole units (20) and a coaxial feeder element (30). The PCB comprises an upper layer (101), and a lower layer (102) opposite the upper layer and fixed on the insulative substrate. The coaxial feeder element includes an RF cable (305), and a neck (303) securely attached around the RF cable for engaging the coaxial feeder element with the substrate. The RF cable has a conducting core wire (301) connected to the upper layer via a jumper wire (304), and an outer conductor (302) around the conducting core wire directly connected to the lower layer. The electronic dipole units are respectively arranged on the upper and lower layers of the PCB, and are respectively coupled to the conducting core wire and the outer conductor. The PCB has space available for accommodating the jumper wire of varying length. The jumper wire has an insulative coating.

Abstract: A dual band antenna structure for transmission electromagnetic energy in two frequency bands. The antenna structure has a substrate with a first side having a first dipole radiating element and a second dipole radiating element. The lengths of the dipole radiating elements are chosen to transmit the first and second frequencies. The antenna structure further includes a first dipole ground disposed in substantially mirror-image relation to the first dipole radiating element and a second dipole ground disposed in substantially mirror-image relation to the second dipole radiating element. The first and second dipole radiating elements are electrically connected to a transformer formed on the first side of the substrate. Electromagnetic energy fed to the transformer in the first frequency band is transmitted by the first dipole radiating element while electromagnetic energy fed to the transformer in the second frequency band is transmitted by the second dipole radiating element.

Abstract: An adjustable antenna for receiving broadband signals. The antenna includes a first elongated antenna rod that is held next to a second elongated antenna rod in a parallel orientation to the first elongated antenna rod. The antenna rods are supported by a clamping or supporting device that allows the two rods to be slid relative to one another so that the antenna may be tuned to a particular frequency. Electrical contacts to the rods are also provided to allow transmission of the collected signal to a desired device.

Abstract: An antenna is described which includes a plurality of antennas stacked on top of each other in a compact cavity. Input match and radiation gain can be enhanced by the application of a capacitor and inductor in the feed of the spiral lowest in the cavity. The antenna can fit into a very compact space while providing circular polarization over the desired bands of the antennas that are isolated.

Abstract: In an antenna system having an array of antenna elements (10, 10′) and circuitry (111, 14) for controlling the phase of each element an arrangement (113) is provided for correcting the phase setting of each element as a function of the position of each element within the array expressed in polar co-ordinates. The phase correction is proportional to the sinusoid of the angular position of the element and proportional to an odd polynomial of radius having at least one term of third order or above. The resulting beam pattern includes low side-lobes in the lower hemisphere and gives rise to only limited and acceptable power loss on transmission. Furthermore, the implementation is rendered very simple, as the phase correction may be calculated element by element.