Abstract: An antenna comprising a rectangular reflector; first and second dipole antennae disposed in front of the reflector and aligned parallel to the long edge of the reflector; rod-shaped first metal conductors arranged parallel to the first and second dipole antennae and separated from the dipole antennae by a distance X1 to the outside in the direction parallel to the short edge of the reflector, and separated by a distance Y1 in the direction perpendicular to the reflector; and rod-shaped second metal conductors disposed at a position separated from the dipole antennae by a distance X2 greater than distance X1 to the outside with respect to each other, and separated by a distance Y2 greater than distance Y1 forward in the direction perpendicular to the reflector.

Abstract: A directional antenna array is provided that includes a driven element and a first parasitic element separated from the driven element with the first parasitic element and/or the driven element having a width that is greater than about one-half a percent (0.5%) of an free-space wavelength of the directional antenna array. Alternatively or in conjunction, the directional antenna array includes a balun structure that is configured to couple the driven element to at least one of an electromagnetic energy source and an electromagnetic sink, and the balun structure includes a dipole structure, a first feed point extending from the dipole structure and a second feed point extending from the first parasitic element.

Abstract: An antenna includes a ground plane and an active antenna element adjacent the ground plane. Passive antenna elements are adjacent the ground plane, and are spaced apart from the active antenna element. First parasitic gratings are adjacent the ground plane and are spaced apart from the active antenna element. Each first parasitic grating is between two adjacent passive antenna elements. A controller selectably controls the passive antenna elements for operating in a reflective mode or a directive mode. The controller includes for each respective passive antenna element at least one impedance element connected to the ground plane, and a switch adjacent the ground plane for connecting the at least one impedance element to the passive antenna element so that the passive antenna element operates in the reflective or directive mode.

Abstract: Multiband antennas are provided that can be embedded in computing devices such as portable laptop computers and cellular phones, for example, to provide efficient wireless communication in multiple frequency bands. For example, monopole multiband antennas, dipole multiband antennas, and inverted-F antennas are provided, which include one or more coupled and/or branch radiating elements, for providing multiband operation in two or more frequency bands.

Abstract: A dual polarized variable beam tilt antenna (10) having a plurality of offset element trays (12) each supporting pairs of dipole elements (14) to orient the dipole element pattern boresight at a downtilt. The maximum squint level of the antenna is a consistent downtilt off of boresight and which is at the midpoint of the antenna tilt range. The antenna provides a high roll-off radiation pattern through the use of Yagi dipole elements configured in this arrangement, having a beam front-to-side ratio exceeding 20 dB, a horizontal beam front-to-back ratio exceeding 40 dB, and is operable over an expanded frequency range.

Abstract: An antenna system can generate RF radiation fields having dual simultaneous polarization states and having substantially rotationally symmetric radiation patterns. The antenna system generates RF radiation patterns where the beamwidths of respective RF fields for respective radiating elements are substantially equal and are relatively large despite the compact, physical size of the antenna system. The antenna system can include one or more patch radiators and a non-resonant patch separated from each other by an air dielectric and by relatively small spacer elements. The patch radiators and non-resonant patch can have predefined shapes for increasing polarization discrimination. The lower patch radiators can be mounted to a printed circuit board that can include an RF feed network and a ground plane which defines a plurality of symmetrically, shaped slots. The slots within the ground plane of the printed circuit board can be excited by stubs that are part of the feed network of the printed circuit board.

Abstract: The invention relates to a small (0.5 wavelength or less) adaptable antenna system. In particular it relates to the use of loaded parasitic components in the antenna aperture for the purpose of controlling the RF properties of the antenna. Such an antenna system is here referred to as a controlled parasitic antenna (CPA). Parasitic elements within the radiating aperture are terminated by active (controllable) impedance devices. A feedback and control subsystem periodically adjusts the impedance characteristics of these devices based on some observed metric of the received waveform. Such antenna systems can provide multifunctionality within a single aperture and/or mitigate problems associated with the reception of an interfering signal (or signals) or multi-path effects. Such antenna systems are particularly suitable to a situation where an aperture size is desired that is too small for the use of an adaptive phased array.

Abstract: An antenna having a central active element and a plurality of passive dipoles surrounding the active element is disclosed. The passive dipoles increase the antenna gain by increasing the radiated energy in the azimuth direction. In another embodiment a plurality of parasitic directing elements extend radially outward from the passive dipoles.

Abstract: A multiple-element antenna for a wireless communication device is provided. The multiple-element antenna includes a first antenna element having a first operating frequency band, a second antenna element having a second operating frequency band comprising a plurality of operating frequency sub-bands, and a bandwidth enhancing parasitic element positioned adjacent the second antenna element to electromagnetically couple to the second antenna element and thereby enhance the bandwidth of the second antenna element. In one embodiment, the multiple-element antenna is fabricated on a single dielectric substrate and implemented in a wireless mobile communication device having a first transceiver and a second transceiver, with the first antenna element connected to the first transceiver and the second antenna element connected to the second transceiver.

Abstract: An antenna and a wireless mobile communication device incorporating the antenna are provided. The antenna includes a first conductor section electrically coupled to first feeding point, a second conductor section electrically coupled to a second feeding point, and a near-field radiation control structure adapted to control characteristics of near-field radiation generated by the antenna. Near-field radiation control structures include a parasitic element positioned adjacent the first conductor section and configure to control characteristics of near-field radiation generated by the first conductor section, and a diffuser in the second conductor section configured to diffuse near-field radiation generated by the second conductor section into a plurality of directions.

Abstract: A built-in antenna device that broadens bandwidth and that realizes further miniaturization and thin-modeling without making a device itself a flat shape, while still enhancing gain and reducing SAR (specific Absorption Rate). The self impedance of dipole antenna 12, the self impedance of parasitic element 14, and the mutual impedance between dipole antenna 12 and parasitic element 14 change as the length and girth of dipole antenna 12 and parasitic element 14, and the distance therebetween are adjusted to predetermined levels, so as to broaden bandwidth by changing the input impedance of built-in antenna 10.

Abstract: A shaped antenna element that radically reduces the physical size needed for resonance without the use of lossy loading elements, while at the same time allowing direct connection to a coaxial feeder. The element is composed of at least two sub-elements in close proximity to each other, coupled electrically to each other such that the radiation resistance of the composite element is increased substantially. The composite element can be used either as an antenna that consists of multiple such elements in order to provide increased directivity.

Abstract: An antenna having a central active element and a plurality of passive dipoles surrounding the active element is disclosed. The passive dipoles increase the antenna gain by increasing the radiated energy in the azimuth direction. In another embodiment a plurality of parasitic directing elements extend radially outward from the passive dipoles.

Abstract: An antenna for radiating and receiving electromagnetic radiation constructed substantially of Titanium, and in particular Grade 2 or Grade 4 Titanium.

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: A compact microstrip antenna having elements comprising a Yagi-Uda array is provided for use in an apparatus communicating through the antenna. The microstrip Yagi-Uda antenna is adapted for use in an apparatus such as a cellular phone, PDA, laptop computer, or a vehicle having a telematices device.

Abstract: An antenna array having a central active element and a plurality of passive elements surrounding the active element is disclosed. A dielectric substrate or other slow wave structure is disposed radially outwardly from the passive elements for slowing the radio frequency waves so as to increase the antenna directivity by reducing the amount of energy radiated in the elevation direction.

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 assembly for wireless communications has various components to minimize signal influence when transmitting signals to minimize undesirable loop formation phenomena caused by (positive) feedback of signals. Signal wave scattering and diffraction causing back lobe radio frequency (RF) patterns are minimized by a particular antenna assembly structure having a reflector and at least one attenuating structural member, a metallic mesh wrapping the power cable of a feeder, a non-conductive antenna support structure, or any combination thereof. The dimensions of the various components, in particular the reflector and attenuators, can be varied according to desired wireless communications environment.

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 invention concerns a vertical polarisation antenna comprising dipoles at different levels of an elongated vertical support structure. The invention is characterised in that it comprises only one of said dipoles (1, 2) per level of said structure (3) and said dipoles are coplanar and substantially collinear on said structure, but inverted with respect to one another.

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 low specific absorption rate broadband antenna assembly for use with a wireless communication device. The antenna assembly includes a driven element and a parasitic element which are operatively connected to a radio frequency input/output port and a ground plane, respectively, and which are superposed above a predetermined region of a ground plane having a predetermined configuration. The driven and parasitic elements may take the form of traces or wires which are disposed away from each other by a distance related to the frequency of operation. The traces may be formed on one side of a suitable dielectric substrate such as a printed circuit board, while the wires may be self supporting and not requiring a dielectric substrate.

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 system can generate RF radiation fields having dual simultaneous polarization states and having substantially rotationally symmetric radiation patterns. The antenna system generates RF radiation patterns where the beamwidths of respective RF fields for respective radiating elements are substantially equal and are relatively large despite the compact, physical size of the antenna system. The antenna system can include one or more patch radiators and a non-resonant patch separated from each other by an air dielectric and by relatively small spacer elements. The patch radiators and non-resonant patch can have predefined shapes for increasing polarization discrimination. The lower patch radiators can be mounted to a printed circuit board that can include an RF feed network and a ground plane which defines a plurality of symmetrically, shaped slots. The slots within the ground plane of the printed circuit board can be excited by stubs that are part of the feed network of the printed circuit board.

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: 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: 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: 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: An antenna arrangement is provide with a variable parasitic element whose position is varied as a function of the scan angle. According to an exemplary embodiment of the invention, a variable scanning array dual polarized antenna provides different scan angles by varying phase elements of the array. According to this embodiment an adjustable phase shift mechanism is used to modify the phase of the antenna array. The adjustable phase shift mechanism is used changes the antenna's phase as a function of a moveable dielectric slab. The dielectric slab slides over a microstrip line that results in a phase change that is a function of line coverage. A parasitic element is also connected to the dielectric slab such that the position of the parasitic element is varied in response to a change in the phase shift mechanism thereby varying the canceling signal of the parasitic element to optimize port isolation for the dual polarized antenna.

Abstract: An indoor cellular band antenna has an outer metal housing having a 90° inner configuration and a radome positioned over the front of the housing. An antenna dipole is mounted in the housing and includes two dipole members. Each dipole member includes a rectangular dipole element extended transmission balun members and a back mounting plate. An antenna cable extends through the top panel of the housing. An outer conductor of the cable is electrically connected to one of the transmission balun member of one dipole member and an inner conductor is electrically connected to the dipole element of the same dipole member. The inner and outer conductors of the cable are mounted to the dipole member by connectors formed from the dipole member.

Abstract: An antenna structure including a driven antenna element is formed on a substrate that is folded to provide a closed surface, causing the substrate to be nonplanar and spacing the driven antenna element from a base of the substrate. Adhesives on an outside surface of the substrate permit fastening of the folded substrate to a container or packaging. The substrate may have one or more resilient elbows formed by folding, to bias the antenna element carrying portion of the substrate from the base of the substrate. A modulation circuit may drive the driven antenna element. The flexible substrate may be folded into any of a variety of forms such as a substantially O-shape, a substantially oval shape, a substantially coil shape, a substantially spiral shape, and a substantially S-shape. Additional folds in the substrate may provide surfaces for mounting passive or parasitic antenna elements, such as reflectors and directors, to form a Yagi antenna structure.

Abstract: An antenna array includes two acutely bent dipole antenna elements placed back-to-back on a printed circuit board with integrated micro-strip balun transformers which a Wilkinson divider drives 180 degrees out of phase. In an embodiment, the antenna array sits on a vertical blade support structure to form a T-Top section.

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 combined VHF/UHF active antenna, suitable for indoor use, includes a common element that serves as a reflector for UHF signals and as a director for VHF signals. The VHF element is bent upon itself to permit its packaging as a consumer product accessory.

Abstract: An impedance matching circuit in accordance with the principles of the present invention employs series-connected transmission lines to match a high reflection coefficient source impedance with a load impedance. The matching circuit is formed on a dielectric substrate material and accommodates the relatively limited capabilities of photo-lithographic circuit production. The new impedance matching circuit may be constructed of three series-connected transmission line sections. A first section, the section that is to be connected to the source, transforms the high source impedance into a relatively low valued impedance that is substantially resistive. The reflection coefficient of the first section is substantially equal to the reflection coefficient of the source. A second may be implemented as a quarter-wave transformer that transforms the low impedance developed by the first section into an intermediate impedance value.

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: An antenna, used as a voltage and power source, is designed to operate with an arbitrary load, or front end. One or more stubs are added to one or more of the antenna elements. The stubs act as two conductor transmission line and are terminated either in a short-circuit or open-circuit. Where the transmission line is odd multiples of the guided wavelength in length, the short-circuit stubs act as lumped inductors and the open-circuit stubs act as lumped capacitors. The magnitude of these lumped capacitors and inductors (reactances) is affected by a stub length, a stub conductor width, and a stub spacing. Zero or more short-circuit stubs and zero or more open-circuit stubs are added to one or more of the antenna elements to change the reactive (imaginary) part of the antenna input impedance. In a preferred embodiment, the reactive part is changed to equal the negative magnitude of the reactive part of the front end input impedance.

Abstract: An antenna assembly for transmitting a radio signal from a radio signal transmitting device includes an antenna unit comprised of a dipole driven antenna member for transmitting a radio signal from the radio signal transmitting device. A radiation reflector reflects the radio signal transmitted by the driven antenna member, and a support member supports the driven antenna member and the radiation reflector so that a predetermined gap is precisely maintained between the driven antenna member and the radiation reflector. A shielding member shields a portion of the radio signal transmitted by the driven antenna member in a direction toward the shielding member. The antenna unit is pivotally mounted so that it is disposable at selectable positions relative to the shielding member. The output of the radio signal transmitted by the driven antenna member can be controlled depending on a position of the antenna unit. The dipole driven antenna member comprises a first and a second segment made from a metal foil.

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: An antenna used as a voltage and power source is designed to operate with arbitrary load, or front end. The antenna has one or more (number of) loading bars that are placed adjacent to the elements of the antenna at a spacing distance. The real part of the antenna input impedance is changed by adjusting the loading bar length, width, and/or spacing distance and/or the number of loading bars. These changes are implemented to reduce the real part of the antenna input impedance to make it small enough to develop an adequate voltage, Vp, to operated the front end and connected circuitry. In a preferred embodiment, the real part of the antenna input impedance is reduced to the point at which Vp no longer increases. One or more stubs is added to one or more of the antenna elements. The stubs act as two-conductor transmission line and is terminated either in a short-circuit or open-circuit. The short-circuit stubs act as a lumped inductor. The open-circuit stub acts as a lumped capacitor.

Abstract: The reflector-provided dipole-antenna shows outstanding performance in a wide frequency range and allows simultaneous transmission and reception at different frequencies. A dipole antenna element is provided at the back of a dielectric substrate set to the reflector surface. A parasitic element is provided on the front of the dielectric substrate, which is constituted by forming and protruding the central portion of a linear conductor forward in an almost trapezoidal shape, for example. The protruded portion is set to a position corresponding to the front of the feed point of the dipole antenna element and the portions of the said parasitic element towards the ends are set to positions corresponding to the rear of the dipole antenna element. A feed circuit provided on the face side of dielectric substrate is connected to a coaxial connector provided at the back of the reflector.

Abstract: A dual band antenna assembly is described to include a pair of dual band active radiating elements disposed upon a dielectric substrate. A pair of LC traps and conductor elements are electrically coupled to the radiating conductor elements to provide dual band resonance for cellular telephone and PCS device bandwidth ranges. Additional performance may be achieved with parasitic reflector and director elements. The multi-element directional antenna finds particular applicability for in-vehicle and wireless communication use.

Abstract: Although conventional antennas have characteristics suitable for mobile radio base stations, their vertical dimension is large, and locations of their installation are limited. A radiator for an first upper antenna 32 is arranged in a hollow nonconductive radome 2, using an internal conductor 7a and a metal pipe 10. A radiator for a second lower antenna 34 is arranged in the radome 2, using metal pipes 14 and 15. Two parasitic elements 31 are installed substantially in parallel with the first antenna 32 below a feeding point 9. Two parasitic elements 33 are installed substantially in parallel with the second antenna 34 above a feeding point 13. These allow the tilt angle to be freely set between -10.degree. and +10.degree. by adjusting the parasitic element length and the antenna to be reduced in size.

Abstract: An antenna system is adapted to be installed on a ceiling surface or on one of side wall surfaces of a space defined by the ceiling surface, the side wall surfaces and a floor surface. The antenna includes a reflector and a radiator element. The reflector has a grounded plate, a dielectric layer formed on the grounded plate, and metal strips having patterns parallel to the longitudinal direction of the space and formed on the dielectric layer. The radiator element is disposed to be perpendicular to a reflecting surface of the reflector. The radiator element may be in a bar form, a cylindrical form or at least partly a coil form. The distance between the center of the longitudinal direction of the radiator element and the reflector is set to be about 0.1 to 0.6 times the wavelength of the working frequency. The antenna system has high directivity along an elongate space such as a tunnel, a corridor or an underground shopping area.

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 for use in a portable radio apparatus, which has a pair of bands extending from the main body of the apparatus, for securing the apparatus to a user. A first antenna conductor supplied with power and a second antenna conductor not supplied with power are embedded in each band and extend parallel to the axis of the band. The first and second antenna conductors embedded in the first band are connected at one end to the first and second antenna conductors embedded in the second band. No load is connected to the second antenna conductor embedded in each band. The second antenna conductor embedded in each band performs different functions according to its length. If it has a length equal to or greater than half the wavelength .lambda. of waves to receive, it will function as a reflector. If it has a length less than half the wavelength .lambda. of the waves, it will function as a director.

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: A multi-element directional antenna and process for making same are described. The antenna comprises a lightweight dielectric substrate having an array of parasitic elements disposed on the substrate. A printed circuit board having a ground plane on one side thereof, and a driven element and phasing means comprising a hybrid (magic-or-twin) tee junction on the other side thereof, disposed coplanar with the parasitic elements and the substrate. The multi-element directional antenna, may be formed using low labor cost manufacturing process such as stamping and laminating, and additive and/or subtractive (i.e. etching) techniques.