Abstract: A phased array antenna includes a substrate having a first surface, and a second surface adjacent thereto and defining an edge therebetween. A plurality of dipole antenna elements are on the first surface, and at least a portion of at least one dipole antenna element is on the second surface. Each dipole antenna element includes a medial feed portion and a pair of legs extending outwardly therefrom. Adjacent legs of adjacent dipole antenna elements on the first and second surfaces include respective spaced apart end portions having predetermined shapes and relative positioning for providing increased capacitive coupling between the adjacent dipole antenna elements.

Abstract: The fast switching multifunction antenna of the present invention is a variable length antenna that may be switched to provide the equivalent function of a broadband antenna. The variable length antenna quasi-continuously transmits or receives signals at a plurality of frequencies by changing the effective length of the antenna using a variety of switching mechanisms. The present invention may comprise a plurality of antenna segments, a plurality of selectively actuable switches for interconnecting the antenna segments, and a switching mechanism operably coupled to the plurality of selectively actuable switches for switching them at a switching rate that is greater than twice the highest frequency to be transmitted or received. The switching rate will be fast enough to allow the antenna to sample the highest frequency and all of the required lower frequencies within the desired frequency range without the loss of information at any frequency.

Abstract: An antenna having a dual-band driven element and a second antenna element simultaneously produces a directional radiation pattern at an upper frequency and an omnidirectional radiation pattern at a lower frequency. The dual-band driven element is formed as a dipole or monopole with at least one choke connected to the end of the dipole or monopole. In an exemplary embodiment, the dual-band driven element includes a central dipole or monopole that has chokes formed as u-shaped extensions located at the ends of the central antenna dipole or monopole. An antenna array includes the dual-band driven element and a second driven antenna element with a reflector and/or a director in a Yagi-Uda configuration. An antenna array includes the dual-band driven element with a reflector or with a reflector and a director in a Yagi-Uda configuration.

Abstract: Disclosed is a side-lobe-modification antenna system comprising: an antenna including a base plate and an RF radiating arrangement attached to the base plate; and a side-lobe modifier bracket having a first planar surface and a second planar surface intersecting the first planar surface. The second planar surface can extend aside the base plate at an angle relative to the first planar surface. The first planar surface can be parallel to and abut the base plate.

Abstract: An antenna system includes a ground plane, an aperture array of patch radiating elements and a feed structure. The feed structure has a first and second beam forming networks that each couple to selected radiating elements to form first and second antenna arrays. At least one and less than all of the radiating elements are shared by the first and second antenna arrays.

Abstract: An antenna array that uses at least two passive antennas and one active antenna disposed above a ground plane, but electrically isolated from the ground plane, and a respective resonant strip positioned beneath each passive antenna. The passive antenna elements are positioned about the active element, and each of the at least two passive antenna elements is individually set to a reflective or a transmissive mode to change the characteristics of an input/output beam pattern of the antenna apparatus.

Abstract: To make improvements in a conventional slotted bow tie antenna to make it possible to (a) broaden the tuning frequency band, (b) function as a dual band antenna, without diminishing the “advantage of enabling a thin shape and possessing directivity”. When the symmetrical axis in the longitudinal direction of the bow tie shaped slot is set as x, and the symmetrical axis perpendicular thereto is set as y, a narrow and long parasitic element is placed over and across in the y axis direction, and this parasitic element is insulated electrically from a metal foil provided with a slot, using an insulator, for example. Further, by using two parasitic elements and arranging them in parallel while electrically insulating them from each other, the antenna can also function as a dual band antenna.

Abstract: A first dipole antenna consisting of dipole antennae 2a, 2b and a second dipole antenna consisting of dipole antennae 2c, 2d are disposed so as to be approximately orthogonal at approximately &lgr;/4 intervals on a reflecting plate 6 having a diameter of approximately &lgr;/2 or more. By disposing a plurality of non-feeding elements 3a to 3h around the first dipole antenna and second dipole antenna and isolating them by approximately &lgr;/4, the transmission gain and axial ratio in a low elevation angle can be improved.

Abstract: An antenna comprises at least two or more radiators such as, especially dual-polarized radiators, and at least one additional passive conducting decoupling elements. The decoupling element, in its longest direction of extension, or at least one component of the decoupling element, with its longest direction of extension, extends in the propagation direction of the electromagnetic waves and/or perpendicular to the plane of the reflector.

Abstract: A dual-polarized, stub-tuned, proximity-fed, stacked patch antenna includes a ground plane layer and a dielectric substrate overlying the ground plane layer. An active patch antenna element is disposed on the dielectric substrate. A parasitic patch antenna element is supported in spaced relation to the active patch antenna element. Dual feed lines are spaced from and field-coupled to the active patch antenna element. Each feed line has a tuning stub for producing a distributed antenna resonance. The dual feed lines are configured to provide dual polarization and minimize coupling between the feed lines. The feed lines are positioned substantially orthogonal to each other to provide orthogonal linear polarizations. Each feed line includes a feed line tip that extends towards the center of the active patch antenna element and spaced from each other to minimize tip-to-tip coupling. Each feed line tip includes a 90 degree bend.

Abstract: This invention presents new and alternative design techniques of single feed Dual/Tri ISM band PIFA for wireless system applications. To attain the advantages of and in accordance with the purpose of the present invention, dual and/or tri ISM band PIFA antennas are provided. In particular, an antenna comprises at least a ground plane, a radiating element, a short, and a feed tab. The short provides a connection between the ground plane and the radiating element. The feed tab connected to the radiating element provides RF power and provides initial impedance match. While the feed tab provides initial impedance match, additional impedance match and frequency control are obtained by the inclusion of one or more of a parasitic element, a slot, tuning stubs, and capacitive elements.

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: A three-band antenna is disclosed, intended in particular for cellular telecommunications. The antenna includes radiating elements operating in three frequency bands. UMTS radiating elements are separated by an optimum distance of 0.95×&lgr;m, where &lgr;m represents the average wavelength of the UMTS frequency band. The positioning of the GSM and DCS radiating elements relative to the UMTS radiating elements is fixed so that each radiating element is similarly surrounded by other radiating elements and by partition walls. The structure is periodic along a longitudinal axis. In each module of the structure, a GSM radiating element is placed at the center of a quadrangle, two adjacent vertices of which are each occupied by a DCS radiating element and the other two vertices of which are each occupied by a UMTS radiating element.

Abstract: An antenna device comprising a conductive earth substrate, a receiving element located in the proximity of said conductive earth substrate and having a receiving terminal, and a transmitting element located in the proximity of said receiving element and having a transmitting terminal, characterized in that an end of said receiving element and an end of said transmitting element are connected to said conductive earth substrate for grounding through a common portion and the frequency band of said receiving element is different from that of said transmitting element.

Abstract: The present invention relates to a device for transmitting and/or receiving electromagnetic waves comprising at least one radiating element for radiating a circular polarization of given sense, characterized in that it comprises at least one means dimensioned and positioned with respect to the radiating element in such a way as to radiate, at the frequency of the radiating element, a circular polarization of opposite sense to that of the radiating element so as to compensate for the cross component of the radiating element. The invention applies more particularly to printed antennas operating under circular polarization.

Abstract: A hand-held dual frequency satellite communication antenna of circular polarization-capable characteristics is disclosed. The antenna system is based on Yagi/Udi spaced elements, including tuned trap-enabled dual frequency elements, disposed in orthogonal planes of a hand-receivable antenna boom element. The antenna system is fabricated from low cost readily obtainable materials and in a manner permitting easy disassembly and packaging for carriage to an isolated location of usage. Configuration of the disclosed antenna system for transmission and reception in two different popular amateur radio satellite communication bands is included. Antenna system field pattern characteristics and actual element lengths are included in the disclosure.

Abstract: A radio frequency (RF) antenna of the present invention generally comprises an electrical conductor and a unitary metallic surface mounting structure. The electrical conductor, which performs the radiator function, is secured to the surface mounting structure so that the electrical conductor may use the surface mounting structure not only as a surface mount but additionally as a ground plane. The surface mounting structure is presented in a cross-configuration having outward extending arms. The arms perform the ground plane function and are bent to a desired angle to produce a desired radiation pattern and/or impedance. A plastic radome with a metallic insert is preferably used to cover the electrical conductor and to secure the electrical conductor to the surface mounting structure.

Abstract: An antenna apparatus includes a dielectric base, and a plurality of feeding-radiating elements having different resonance frequencies, each including a feeding electrode and a radiating electrode which are disposed on surfaces of the base. A stub with a common feeding point is disposed on a mounting substrate which supports the base. The feeding electrodes of the feeding-radiating elements are connected to matching points of the stub, thereby achieving impedance matching for each of the feeding-radiating elements.

Abstract: An antenna system comprising a plurality of dipole elements formed from a single piece of material. The plurality of dipole elements is attached to a reflector plate with a single supporting base and forms horizontally or vertically stacked radiation elements. Tabs located between the center of the single piece and legs of the dipole elements and are bent at an angle to form a symmetrical axis in the center of slots separating the plurality of dipole elements to attenuate the radiation caused by current flowing around the slots. The plurality of dipole elements are selected to achieve different radiation patterns and can be formed into different shapes to achieve different lobe shapes.

Abstract: An efficient antenna pattern shaping structure employs a parasitic element made of a conductive surface next to radio circuitry to shape the pattern of an associated antenna, preferably one that is a quarter wave antenna. The parasitic element is disposed on a first side of the radio circuitry to act as a reflector of electromagnetic energy. The parasitic element has at least two edges and wherein the at least two edges of the parasitic element are bent in a direction towards the radio circuitry in order to shape the antenna pattern more efficiently. The parasitic element is electrically slightly larger than a half wavelength of a frequency band of interest, preferably the low frequency of interest. A optional opposing parasitic element can be disposed on a second side of the radio circuitry opposite the first side. The opposing parasitic element is electrically slightly smaller than a half wavelength of the frequency band of interest, preferably half a wavelength of the high frequency of interest.

Abstract: The present invention provides an RF tag having an antenna that can be selectively tuned to achieve optimal performance. The RF tag comprises an RF transponder integrated circuit and an antenna connected to the RF transponder integrated circuit. The antenna includes components such as tuning stubs and loading bars that are physically alterable to selectively vary the performance characteristics of the antenna. The tuning stub and loading bar may each further comprising a variably selectable length having elements that may be removed by punching, cutting, etching, laser trimming or other process. The antenna may further comprise a leadframe or a flexible substrate.

Abstract: A linear antenna capable of adjusting directivity and impedance matching comprises: a common dipole in which two cylindrical conductors each having a length of &lgr;/4 of the transmission frequency are provided linearly (thus having a total length of &lgr;/2); a plurality of linear parasitic elements that are provided at positions separated by a distance D2 from the axis of the common dipole so as to surround the common dipole; and a U-shaped parasitic element for realizing impedance matching that is arranged in proximity to one end of the common dipole. Each of the linear parasitic elements are arranged parallel to the common dipole and have a length of one half-wavelength of a desired transmission frequency.

Abstract: A one-piece multi-element directional Yagi-Uda antenna comprised of an array of director elements, a reflector element, boom and folded dipole driven element is fabricated from a single piece of conductive material. The method of forming the antenna uses simple, low-cost techniques, such as single and progressive die stamping, punching and forming. The dipole driven element of the antenna is formed by folding the ends of the driven element during the stamping process or in a separate folding step. In an alternative embodiment of the invention, the boom of the antenna array is formed with sufficient length to operatively connect a radome thereto.

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: An antenna system comprising a plurality of dipole elements formed from a single piece of material. The plurality of dipole elements is attached to a reflector plate with a single supporting base and forms horizontally or vertically stacked radiation elements. Tabs located between the center of the single piece and legs of the dipole elements and are bent at an angle to form a symmetrical axis in the center of slots separating the plurality of dipole elements to attenuate the radiation caused by current flowing around the slots. The plurality of dipole elements are selected to achieve different radiation patterns and can be formed into different shapes to achieve different lobe shapes.

Abstract: An antenna system comprising a plurality of dipole elements formed from a single piece of material. The plurality of dipole elements is attached to a reflector plate with a single supporting base and forms horizontally or vertically stacked radiation elements. Tabs located between the center of the single piece and legs of the dipole elements and are bent at an angle to form a symmetrical axis in the center of slots separating the plurality of dipole elements to attenuate the radiation caused by current flowing around the slots. The plurality of dipole elements are selected to achieve different radiation patterns and can be formed into different shapes to achieve different lobe shapes.

Abstract: An omni-directional, planar folded dipole antenna and related quadrature phase shifter implemented on printed circuit boards (PCBs) having differing properties that are perpendicularly engaged. The planar antenna segment is implemented on a single-sided inexpensive PCB and a quadrature phase shifter and system electronics are implemented on more expensive multi-layer PCBs. The invention reduces cost and improves system reliability because coaxial or like connectors of varying material and installation quality are not required between a planar antenna and a quadrature phase shifter. Planar antenna transmits radio frequency signals in an omni-directional pattern and is capable of receiving signals from remote dipole antennas positioned in arbitrary physical orientations. The quadrature phase shifter provides both phase shifting functions and also converts an unbalanced radio frequency transceiver output signal into a balanced input signal to the planar antenna.

Abstract: To reduce sidelobes in the radiation pattern of a phased array dipole antenna, a plurality of parasitic antenna elements are provided adjacent to the array of dipole elements of the antenna. The driven elements of the dipole array and associated director elements are formed as patterned conductor elements on one surface of a thin dielectric substrate. Feed elements for the driven dipole array also comprise patterned conductor elements formed on an opposite surface of the substrate. The feed elements have a geometry and mutually overlapping projection relationship with the conductors of the driven dipole elements, so as to form a matched impedance transmission line through the dielectric substrate with the patterned dipole elements. The parasitic elements are formed on additional dielectric substrates spaced apart from and parallel to the thin dielectric substrate upon which the driven dipole array is formed.

Abstract: A Yagi antenna system consisting of a low noise amplifier (LNA) and a reflector co-located on the same printed circuit board (PCB) as the radiators and directors is disclosed. Furthermore, the balun cable is replaced by surface mount devices whose feed line is implemented in microstrip technology, all co-located on the same printed circuit board.

Abstract: The method of producing antennas and antenna arrays with desired beam widths applies to both single and dual polarization antennas, and controls and modifies the radiation patterns of the antenna's radiating elements by placing appropriately designed parasitic elements in their vicinity.

Abstract: A directional antenna assembly includes a dielectric structure having a surface. An array of wire antenna elements is positioned within or on the surface of the dielectric structure. At least one of the wire antenna elements is active, and the remainder of the wire antenna elements are passive.

Abstract: A planar broadband dipole antenna including a grounded conductor plate, a radiation plate placed over the grounded conductor plate, the radiation plate having printed patterns formed on both sides, and a dielectric interposed between the grounded conductor plate and the radiation plate. Each of the upper and lower surfaces of the radiation plate includes a dipole element for radiating waves, and a feeder for feeding radio frequency signals. Accordingly, the basic advantages of micro strip antennas are included, i.e., small volume, small weight, and natural integration with printed circuits. Also, the radiation losses of the twin feed lines in the planar dipole antenna are extremely low.

Abstract: A parasitic antenna array (Yagi-Uda or loop type) for multiple frequency bands has its driven and parasitic elements interlaced on a single support boom. In a first aspect of the invention, series resonant circuits are located in one or more parasitic director elements in order to minimize the deleterious mutual coupling effect between directors of different frequency bands. In a second aspect of the invention, an inductance is placed across the feed point of the driven element of one or more non-selected frequency bands in order to minimize the bandwidth narrowing effect of closely-spaced driven elements and to provide a desired feed point impedance at the driven element of the selected frequency band. Although the two aspects of the invention may be used without one another, they are advantageously employed together. In addition, the second aspect of the invention may be applied to closely-spaced driven elements that are not part of a parasitic array.

Abstract: An antenna device for receiving and/or transmitting dual polarized electromagnetic waves, comprising at least one antenna element (7). There are disposed parasitic elements (8, 9) of an electrically conductive material in a region, which surrounds the antenna element and includes the space between and including two parallel planes (2, 1) being defined by a ground plane layer (2) and the antenna element (7), respectively. Each parasitic element (8, 9) comprises at least one elongated, longitudinal portion, extending along an associated lateral side of the antenna element.

Abstract: Plural antennas are located sufficiently closely to associated radiation reflective surfaces for consequential reduction of elevation beam-width and increase gain in azimuth. Two pairs of antennas associated with differently directed said radiation reflective surfaces afford diversity action. The antennas can be dipoles and the reflective surfaces can be faces of a housing box for related electronics.

Abstract: An antenna for receiving and/or transmitting electromagnetic waves, comprising an array of antenna elements including at least one longitudinal row of antenna elements (7) located at a distance (d) from each other, each such row of antenna elements being adapted to receive and/or transmit a dual polarized beam including two separate, mutually isolated channels. Along each longitudinal row of antenna elements, in the vicinity of the gap between a respective pair of adjacent antenna elements, preferably at the side of the centre line (C) of the row, there are disposed parasitic elements (8a, 8b) serving to influence the mutual coupling between said adjacent antenna elements in such a way as to improve the isolation between the separate channels.

Abstract: A method and arrangement improve antenna performance parameters. The antenna includes a radiating device for radiating a beam in a substantially predefined direction. The radiating device is provided on a supporting structure. The arrangement includes at least one device to mechanically tilt the radiating device in a first direction substantially diverging from the predefined direction, and a device to tilt the beam in a second substantially opposite direction electrically.

Abstract: Described herein is a variable directional antenna apparatus wherein an electrical length of a parasitic antenna of a paired two-element Yagi antenna is varied to change antenna directivity. A radio device (12) outputs a received signal corresponding to the intensity of an electric field received by a first antenna. A control circuit (15) outputs a control signal to a variable impedance circuit (14) according to the result of detection of the received signal so as to change the impedance of the variable impedance circuit (14) according to the control signal. Thus, an electrical length of a second antenna (13) placed in parallel away from the first antenna (10) is changed to thereby activate the second antenna as a director or reflector, whereby antenna directivity is varied.

Abstract: The present invention relates to antennas. One of the problems which arises during the operation of a linear array antenna with electrical downtilt is that cross-polar radiation currents are generated. These cross-polar radiation currents, if at the same frequency as the operating band of the antenna, interfere with the required gain of the antenna. The present invention provides a solution to cross-polar radiation currents with an antenna assembly comprising first and second apertured ground planes with an antenna probe feed network printed upon a dielectric substrate supported therebetween, the array of radiating elements having different phase input feeds, wherein an outwardly extending ground plane flange extends from one of the apertured ground planes. There is also provided a method of receiving and transmitting signals by means of a layered antenna of this construction.

Abstract: An antenna system is described having a plurality of elements, one of which is an active element for transmitting or receiving signal, the remaining lements acting as reflectors, and wherein the elements may be comprised of a series of diodes connected in series with conductors having a length that is a fraction of the wavelength of the design frequency. When its diodes are biased for conduction, an element can radiate or receive r.f. signals or act as a reflector, and when its diodes are not conducting, the element is transparent to r.f. of the design frequency.

Abstract: A low profile bi-directional antenna is provided for mounting directly to a metal structure, or some other conductive or semi-conductive surface. The antenna includes an insulating antenna tray, a conductive ground plane mounted to a surface of the antenna tray, first and second radiating elements extending from the ground plane, and a radome covering the radiating elements and fastened to the insulating antenna tray. First and second reflector elements are mounted to the surface of the antenna tray on the lateral sides of the ground plane. The reflectors are electrically connected to the ground plane. The radiating elements are supported above and to the lateral sides of the ground plane and reflector elements by support members mounted at acute angles to the ground plane. An RF connector is provided for coupling RF signals to and from the first and second radiating elements.

Abstract: In one embodiment, an antenna has four equally spaced monopole elements mounted in a symmetric array on the outer surface of a solid cylinder structure. The cylinder has a high dielectric constant, and extends from a conductive ground plane. The monopole elements can be switched by switching elements so that one or more is active, with the others acting as parasitic directors/reflectors being connected commonly to ground or left in an open circuit condition to be effectively transparent.

Abstract: A crossed polarization antenna system including a substantially flat and rectangular reflector and at least one radiating cell carried by the reflector, each cell including at least two first conductor elements assembled tail-to-tail and energized by a first external power supply forming a first dipole. Each radiating cell includes two second conductor elements mounted in exactly the same way as the first elements and energized by a second external power supply forming a second dipole. The conductor elements are V-shape bent elements with the second elements mounted orthogonally to the first elements. Applications include mobile telephones.

Abstract: A no-loss, multi-band, adaptable Yagi style antenna employs a multi-element driven cell having a center element and one or more adjacent elements on each side of the center element. The adjacent elements of the driven cell are electrically shorter than the center element, thereby permitting the driven cell to be tuned to two or more frequency bands. The antenna is fed by a feedline connected to a common feed point at the center of the center element in the driven cell. Parasitic director elements are positioned in front of the driven cell and are tuned to the highest band of the driven cell. Parasitic reflector elements for one or more frequency bands are positioned behind the driven cell, with these elements tuned to actual operating frequencies of the antenna.

Abstract: A low cost array antenna (10) employs U-dipole elements (30) inserted into slots in a printed circuit board (18). Board (18), supported in spaced relation directly by back reflector (12), bears a feed network (22) connected to an input/output port (24). The dipole element (30) is a dual-dipole single-feed element, including parallel coextensive dipole segments (32, 34) attached at one end, with a sole signal feed path via feed segment (36). Feed segment (36) is inserted into board (18) and soldered to a feed point of feed network (22). One or more mounting tabs (38) are also inserted into slots in board (18) and may be fixed in place by soldering to an isolated conductor portion provided on board (18) for this purpose. A dual array antenna (50) includes dipoles (51-54) for left slant polarization reception and dipoles (61-64) for right slant polarization reception.

Abstract: An end fire microstrip antenna which is particularly suitable for low-profile applications comprises a dielectric substrate having a first surface and an opposite surface. A driven element, a microstrip fedline and a plurality of (parasitic) director elements are provided on the first surface. These elements extend in the same plane and are spaced apart from each other in a longitudinal or end-fire direction of the antenna. Likewise, the director elements are spaced apart from each other in arrow extending in the end-fire direction. The antenna further comprises a ground plane provided on the second surface. The driven element comprises a conductive strip connected at one end to the microstrip feedline and open-circuit at its opposite end. It has at least one undulation in such same plane. The undulation has at least one limb extending transversely to the end-fire direction. A conductive reflector element may be provided behind the driven element.

Abstract: An antenna which includes a rigid boom and a plurality flexible antenna elements attached to the boom. The antenna elements have curved cross-sections and are made from a material which allows them to resiliently bend upon contacting an object. The antenna is particularly suitable for mobile field use such as tracking objects tagged with radio frequency transmitters. In such use, the flexible antenna elements easily bend when contacting objects such as branches, brush and other vegetation so as not to become entangled and prevent movement of the antenna.

Abstract: An omni directional coverage multibeam antenna relief on a ground surface having simple conical shapes to provide beam steering. One advantage of such a system is that the projected area is always constant and broadside to the intended direction resulting in limited scan loss effects. In the case of a cylinder as the conical shape, z-axis symmetry provides a constant antenna aperture projection in any azimuthal direction. Using this geometry, high level, side lobes are reduced considerably because of the natural aperture tapering from dispersion effects. These side lobes are further reduced by the presence of parasitic elements which also result in the added benefit of an increased front and back ratio. This front to back ratio may be further increased by the use of inverted cosine energization of selected antenna elements.

Abstract: The present invention is an improved Yagi-Uda style antenna. Primarily, the present invention provides that at least two driven elements are spaced approximately 0.1 .lambda. apart from each other. The driven elements are forced into a critical couple mode by electrically connecting the two driven elements with a matched phasing delay line. The phasing delay line retards the phase current sufficiently to, coupled with the specified element separation, satisfy both the endfire condition and the Hansen-Woodyard condition. This provides for increased directivity and gain, and deep nulls in the field strength. The at least two critically coupled elements compromise at least a first driven element, which is the primary broadcast element, and a second driven element, which is a driven reflector element. The reflector element acts to augment field strength in a direction toward the first driven element and reduce field strength in a direction away from the first driven element.

Abstract: An antenna element comprised of an hollow conductor and a central grounded onductor within the hollow conductor, there being a variation in capacitance between the hollow conductor and the central conductor along their length.