Abstract: The invention provides an elongate antenna having a radiating portion constituted by an elongate conductor element. The elongate element is machined to include: N dipoles (where N is an integer not less than 2) made up of N rectilinear sections of said element in alignment; and N?1 phase-shifter elements, each phase-shifter element being interposed between two consecutive dipoles, each phase-shifter element having a section of the elongate conductor element folded into a U-shape and having branches which are substantially juxtaposed and which extend in a direction that is orthogonal to the common direction of the dipoles.

Abstract: Frequency-dependent phase center movement in near-field, unshielded, electromagnetic susceptibility testing using a log-periodic dipole can be significantly reduced by bending the rearmost dipole elements forward. Each bent dipole element has an inner portion and an outer portion connected to each other at a bend, the inner portion extending outward from a boom in substantially perpendicular relation to the boom, and the outer portion extending obliquely outward and forward from the bend. The frequency range of the antenna can be extended by forming each element of the longest dipole with an undulating shape when viewed in a direction along the boom.

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: A dual polarized folded dipole antenna comprising: a first unit configured for transmitting and/or receiving signals in a first polarization direction; and a second unit configured for transmitting and/or receiving signals in a second polarization direction. Each unit includes an integrally formed feed section a radiator input section, and radiating section. The feed section is a microstrip feed section, and the radiator input section includes a balun transformer. The antenna has a coaxial to microstrip transition comprising a microstrip transmission line on a first side of the ground plane; and a coaxial transmission line on a second side of the ground plane opposite to the first side of the ground plane. A conductive ground transition body is in conductive engagement with the sleeve of the coaxial line; and a ground locking member applies a force to the ground transition body so as to force the ground transition body into conductive engagement with the ground plane.

Abstract: Folded dipole antenna elements (2, 4) are disposed generally in parallel, being spaced by a distance smaller than a quarter of the wavelength employed. The antenna elements (2, 4) are connected to a combiner (16) via feeders (12, 14) having different lengths. The difference in length between the feeders (12, 14) is such that received signals resulting from a radio wave coming to the antenna elements (2, 4) from the front and received by the antenna elements (12, 14) are in phase with each other at the inputs (16a, 16b) of the combiner (16), whereas received signals resulting from a radio wave coming to the antenna elements (2, 4) from the back and received by the antenna elements (12, 14) are 180° out of phase with each other at the inputs (16a, 16b) of the combiner (16).

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 capacitively loaded magnetic dipole antenna is provided with a portion that comprises a length that is longer than a straight line distance between a first end and a second end of the third portion such that antenna with a tower profile and/or smaller form factor is achieved.

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: A bended dipole antenna, which comprises an antenna substance and a radiator led out from the antenna substance, is characterized in that: the conductor in the radiator is bended and an included angle is formed between the radiator and the antenna substance, thus the antenna can be assembled to most positions of a personal electronic apparatus for wireless transmission, and a well effect on both vertical polarization and horizontal polarization can be accomplished.

Abstract: Multi-frequency, low-profile, capacitively loaded magnetic dipole antennas to be used in wireless communications. Each antenna comprises one to n antenna elements and each element having one to n arms. The various antenna embodiments can cover a range of frequencies to be determined by the shape, size, and number of elements in the physical configuration of the antenna. The antenna configuration can also be adapted to expand frequency bands covered by the antenna or to fit within space restrictions dictated by specific antenna applications.

Abstract: A one-wavelength loop antenna element (103) shaped like a rectangle is placed close to a radio base plate (101) and further is bent at both end parts toward a feeding section, whereby a current distribution where the current at the tip of turn up becomes zero is formed. Current is concentrated on the loop antenna element (103), so that the current component flowing onto the top of the radio base plate (101) is decreased, the effect produced when a human being carries a radio containing an antenna including the loop antenna element is suppressed, and the directivity responsive to an arrival wave is formed.

Abstract: A multiple-element antenna is provided that includes a monopole portion and a dipole portion. The monopole portion has a top section, a middle section, and a bottom section. The middle section defines a recess between the top and bottom sections, and the bottom section includes a monopole feeding port configured to couple the monopole portion of the multiple-element antenna to communications circuitry in a mobile communication device. The dipole portion has at least one dipole feeding port configured to couple the dipole portion of the multiple-element antenna to communications circuitry in the mobile communications device. The dipole portion of the multiple-element antenna is positioned within the recess defined by the monopole portion of the multiple-element antenna in order to electromagnetically couple the monopole portion with the dipole portion.

Abstract: A single piece twin folded dipole antenna for transmitting and receiving electromagnetic signals is provided. The antenna includes a conductor extending in a V-shape at an angle of approximately 45 degrees adjacent to a ground plane. The conductor includes a feed section, a radiator input portion, and a radiating portion. The radiator input portion includes a first radiator input section and a second radiator input section whereby the radiator input sections are integrally formed with the radiating portion. The radiating portion includes a first radiating section and a second radiating section connected in parallel whereby each radiating section includes a fed dipole and a passive dipole.

Abstract: A simple internal or partly internal antenna system for optimizing the radiation pattern from hand held wireless communications devices HHWCD such as hand-held data devices and cellular telephones is disclosed. The antenna system consists of an essentially internal or partly internal asymmetrical dipole with quarter-wave resonator section and radiating planar section, in conjunction with a planar parasitic director element. The radiating planar section may be the ground traces of the HHWCDs printed wiring board PWB. The antenna system provides for single or multiple frequency band operation.

Abstract: A broadband folded dipole antenna has a pair of load resistors in the vicinity of the edges of the antenna element for obtaining a unidirectional beam pattern.

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: An antenna for broadband multiplexing is disclosed. The antenna includes a first set of curved dipole members and a second set of curved dipole members arranged in a helical shape. One set of the dipole members is set with approximately 36° between each dipole member in the set. The other set of dipole members is set with approximately 27.5° between each dipole member in the set. The setting of the dipole members at the designated angles increases the bandwidth that the antenna can accommodate.

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 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: A folded dipole antenna for transmitting and receiving electromagnetic signals is provided. The antenna includes a ground plane and a conductor extending adjacent the ground plane and spaced therefrom by a first dielectric. The conductor includes an open-ended transmission line stub, a radiator input section, at least one radiating section integrally formed with the radiator input section, and a feed section. The radiating section includes first and second ends, a fed dipole and a passive dipole. The fed dipole is connected to the radiator input section. The passive dipole is disposed in spaced relation to the fed dipole to form a gap. The passive dipole is shorted to the fed dipole at the first and second ends.

Abstract: A folded dipole antenna for transmitting and receiving electromagnetic signals is provided. The antenna includes a ground plane and a conductor extending adjacent the ground plane and spaced therefrom by a dielectric. The conductor includes three sections: a feed section, a radiator input section, and at least one radiating section integrally formed with the feed section. The radiating section includes first and second ends, a fed dipole and a passive dipole. The fed dipole is connected to the radiator input section. The passive dipole is disposed in spaced relation to the fed dipole to form a gap. The passive dipole is shorted to the fed dipole at the first and second ends.

Abstract: A collapsible antenna is provided; it is preferably a folded dipole antenna. The antenna has a main body section and two arm sections attached to the main body. At least one of the arms may be moved from an extended position to a collapsed position, thereby reducing the overall length of the antenna. Preferably, the arms may be rotated or pivoted from a first expanded configuration in which they extend in opposite directions from one another to a second collapsed configuration in which they subtend an angle substantially less than 180°. Preferably, the arms extend from the body section in substantially the same direction when they are in the collapsed configuration. A locking mechanism selectively secures the arms in both configurations. Alternatively, one or both arms may telescope. The invention also includes mutual inductance cancelling coils for further reducing the overall length of the antenna without reducing the effective length of the antenna.

Abstract: A self-contained four-dipole element provides a 360 degree phase-progressive-omnidirectional (PPO) circularly polarized antenna pattern. Via a single signal port, a PPO excitation network incorporated into the element excites the four dipoles at phases differing by successive 90 degree increments. The four-dipole element is adapted for efficiently reproducible fabrication using printed circuit techniques. Antennas employing a stack of the elements provide a hemispherical antenna pattern with PPO circular polarization and a sharp cutoff below horizontal. For GPS reception in Differential GPS aircraft landing applications, a 21 element antenna provides multipath suppression and a unitary phase center enabling avoidance of signal phase discrepancies. More or fewer elements may be employed in other applications.

Abstract: Conductive tongues project from two places on the axial direction tip of a first antenna element, which projects outwardly from the case of a radio device. When a second antenna element, freely movable in the axial direction, is extracted, the two conductive tongues conductively connect to the base of the second antenna element, and are mutually short-circuited.

Abstract: The present invention provides an auxiliary or side lobe cancelling antenna particularly for horizontally polarised main antennas. The auxiliary antenna arrangement for cancelling side lobe interference from a main antenna comprises a ground plane shaped in a concertina or zig-zag fashion. Dipole pairs are spaced from and arranged perpendicular to the front bends, the dipoles having ends angled towards corresponding ground plane sections. The dipoles are connected anti-phase to provide a radiation pattern approximating an ideal auxiliary antenna mask of the main antennas pattern.

Abstract: A conductor is provided from a base to a first fold point at the tip side, and sequentially folded parallel not less than once at the tip side and the base side, forming a first element; the conductor is split at the first fold point and the split conductor is, similarly, sequentially folded parallel not less than once at the tip side and the base side, forming a second element. Then, the effective length from the base to the tip of the first element is set to a quarter of the wavelength of a first frequency, and the effective length from the base to the tip of the second element is set to a quarter of the wavelength of a second frequency.

Abstract: A folded-dipole antenna element, that is modified so that the two matching conductors are located on opposite sides of the main conductor. Such staggered folded dipoles are superior for constructing log-periodic antennas, because they allow relatively small and straight feeder conductors and they allow the whole antenna to be grounded.

Abstract: A cavity-backed microstrip dipole antenna array is provided with a microstrip feeder network and a plurality of dipoles which are etched and formed on a single printed circuit board (PCB). Therefore, the structure is simple and inexpensive. Moreover, the antenna array can operate over a wider frequency bandwidth, and the thickness can be reduced to 0.1 of the wavelength of the transmitted/received signal.

Abstract: A wireless transceiver includes a dielectric substrate having first and second major surfaces on which an RF circuit and a baseband processing circuit are mounted, and a printed circuit antenna formed on the substrate. The printed circuit antenna has at least one director formed by strip conductors disposed on the substrate, a reflector formed by the edge of a ground area disposed on the substrate, and a dipole formed by strip conductors on the substrate. The dipole is positioned between the reflector and the director. An antenna with this low profile and compact antenna structure has high directivity.

Abstract: A directional antenna for telecomunication base station applications for home or business is provided. A folded dipole, a passive reflector, a balun and selectively routed coaxial transmission line all enclosed in a plastic enclosure provide improved stability of operating parameters when subjected to significant installation variations. The use of a PVC or similar plastic enclosure results in increased bandwidth while permitting printed circuit techniques and similar electronic construction methods the necessary protection and structural integrity.

Abstract: A broad band electrically small antenna comprising opposed wire triangular outline shaped elements connected to a source or receiver at their respective apexes and a second set of wire triangular outline shaped elements connected to the base members of the first set of triangular shaped or "bowtie" elements and extending generally parallel thereto and spaced from the first set. The antenna exhibits a low antenna factor and voltage standing wave ratio at relatively low frequencies in the range of 20 to 200 megahertz, for example. The folded triangular shaped element antenna is connected to a log periodic dipole antenna array to provide broad band reception and transmission characteristics. A second single plane or folded triangular element or bowtie antenna may be mounted on and electrically connected to the array to improve the operating range of the antenna.

Abstract: A skewed Log Periodic Dipole Array (LPDA) used as the element in a linear or planar array, serves to remove the element spacing restriction and hence eliminates the grating lobe problem. The skewed form of the device has all dipoles greater in length than the shortest one, i.e. the highest frequency one, skewed such that they are "Z" shaped. When the angle between the end and center segments of the Z dipole is 90 degrees, the skewed LPDA has a constant width equal to the length of the highest frequency dipole.

Abstract: An E-field generator for r.f. susceptibility testing comprises first and second conductive arms, each comprising a conductor having a U-shaped portion. A driving circuit connected to first ends of each conductor delivers r.f. power to the arms. A load resistance is connected between the opposite ends of the conductors. The U-shaped portions of the elements are disposed opposite each other in spaced relationship so that a device to be tested can be positioned between them. The elements are mounted on a housing which encloses the load resistance as well as a 9:1 balun. The elements are removably secured in clamps, and the housing has provisions for mounting in alternative positions.

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: A folded dipole microstrip antenna is disclosed herein. The microstrip antenna includes a dielectric substrate for defining a first mounting surface and a second mounting surface substantially parallel thereto. A folded dipole radiative element is mounted on the second mounting surface. The microstrip antenna further includes a microstrip feed line, mounted on the first surface, for exciting the radiative element in response to an excitation signal. In a preferred implementation of the microstrip antenna an excitation signal is applied to the microstrip feed line through a coaxial cable. In such a preferred implementation the folded dipole radiative element includes a continuous dipole arm arranged parallel to first and second dipole arm segments separated by an excitation gap. The feed element is mounted in alignment with the excitation gap and is electrically connected to the continuous dipole arm.

Abstract: A dipole antenna with folded back ends. Linear conductor elements are fed by a balanced two-wire transmission line which is connected to a balun transformer in turn connectable to a coaxial line. Preferably, the balun transformer is a small device, made of a ferrite donut wound with thin wire and occupying less than one cubic inch. The transformer is preferably located at the feed point and can then be incorporated into the antenna.

Abstract: A multifunction antenna system is selectively operative over the UHF and VHF frequency ranges using a novel arrangement of symmetrically disposed phased radiating elements that function as a dipole turnstile type array at UHF and as a monopole at VHF. At VHF the UHF radiating elements and feedlines are fed in parallel against ground to produce a pattern similar to that of a short vertical monopole. VHF and UHF coupling networks offer low VSWR and minimize circuit losses when utilized with a folded dipole array. The compact, lightweight structure is adaptable to oceanic communications by installing in a towed radome adapted for water flotation, and provides low angle hemispherical UHF radiation without pattern switching, with the water surface providing a reflective ground plane.

Abstract: A small, collapsible, high-gain, dipole antenna and a method to make the antenna. The present invention provides a collapsible half-wavelength dipole antenna for use in a portable device, the antenna having a fully collapsed position and a fully extended position. The antenna includes a static dipole arm, and a movable dipole arm. The movable dipole arm is capable of being moved to the fully collapsed position and the fully extended position. The antenna also includes a balun feed assembly electrically coupled to the static dipole arm and to the movable dipole arm. The antenna is capable of transmitting and receiving electrical signals in either the fully collapsed position or the fully extended position. The balun feed assembly is fixed to the static dipole arm, and the movable dipole arm is movably coupled to the balun feed assembly.

Abstract: A folded dipole microstrip antenna is disclosed herein. The microstrip antenna includes a dielectric substrate for defining a first mounting surface and a second mounting surface substantially parallel thereto. A folded dipole radiative element is mounted on the second mounting surface. The microstrip antenna further includes a microstrip feed line, mounted on the first surface, for exciting the radiative element in response to an excitation signal. In a preferred implementation of the microstrip antenna an excitation signal is applied to the microstrip feed line through a coaxial cable. In such a preferred implementation the folded dipole radiative element includes a continuous dipole arm arranged parallel to first and second dipole arm segments separated by an excitation gap. The feed element is mounted in alignment with the excitation gap and is electrically connected to the continuous dipole arm.

Abstract: A modified folded dipole antenna (20) comprises a central feeder (23), first and second portions (38 and 40) coupled to the feeder. The first and second portions have first and second folded ends (42 and 44). The folded ends are in close proximity to each other and are electromagnetically coupled to each other. Thus, a modified folded dipole antenna is formed which receives and/or transmits radio signals in at orthogonal orientations.

Abstract: An antenna device includes a base, a metal band having two opposite ends, a reel disposed within the base and having one end of the band connected thereto for winding the band thereon, the opposite end of the band being received in the base, and a guide receives the band outside the base for forming the band into substantially horizontal and vertical components, and for adjusting the length of the horizontal and vertical components of the band.

Abstract: An antenna apparatus in which flexible antennas made of a conductive material are formed on a flexible insulating sheet. An insulating film made of a synthetic resin material is used as the insulating sheet, and the antennas are formed by adhering a metal foil on the insulating sheet or by depositing a metal film on the insulating sheet.

Abstract: An antenna for a low profile portable communications receiver is described. The antenna comprises a conductor formed into a single turn loop having a first set of parallel opposed sides one quarter wavelength or less in length at the operating frequency and a second set of parallel opposed sides, substantially shorter than the first set of sides. The loop terminates in connection tabs symmetrically about the midpoint of one of the first set of sides for connection to a receiver. A dielectric core is interposed within the loop, substantially filling the loop. With the core within the loop, the loop also functions as a halfwave electric dipole thereby providing an antenna responsive to both the magnetic and electric fields of an electromagnetic wave.

Abstract: An antenna array with circular symmetry made up of an array of cylindrica shaped printed circuit elementary antennas. It is made up of small radiating sources which are placed in superposed circles on a cylindrical surface. The sources are distributed at constant angular intervals on the circles. They have little coupling between themselves. On each circle of sources, they are energized in phase and with the same amplitude. An angular phase shift can be provided between the group of sources on a circle and those of another circle. The antenna can be energized by a three-layer printed circuit line. It can be made up by an array of doublets folded into sheets. Inside the cylinder the transmitter is installed to which is applied a signal to be transmitted and which supplies the modulated carrier to the array of radiating sources.

Abstract: The invention relates to an antenna for receiving and modulating transmitted signals having a very low power density on the order of below 1 watt per meter squared, at a selected center frequency above 2,000 MHz. The antenna uses a folded planar dipole section having two separated oppositely disposed U-shape elements, each of said elements having a pair of ends. A capacitor is series-coupled between two of the oppositely disposed ends of the elements, and a diode having a high impedance at the selected center frequency is series-coupled between the other two oppositely disposed ends of the U-shape elements. A metallic backplane is mounted parallel to the planar folded dipole section and spaced from the dipole section a predetermined distance selected to reduce the antenna impedance. The impedance of the diode, the shape of the folded planar diode section and the predetermined amount of spacing of the backplane from the planar folded dipole section are all selected to increase the d.c.

Abstract: The foreshortened dipoles of the antenna described in U.S. Pat. No. 3,732,572 are further substantially shortened with a new construction in which each radiating element comprises two portions. A planar rectangular body electrically connects to the feed point by a stem portion which attaches to the rectangular body at the farthest point from the feed point and is spaced slightly from the plane of the body to electrically isolate the two portions.

Abstract: The foreshortened dipoles of the antenna described in U.S. Pat. No. 3,732,572 are further substantially shortened without performance impairment with a new construction in which each radiating element comprises a planar rectangular body electrically connected to the feed line by a stem attached to the body remotely from the feed line and spaced slightly from the plane of the body.

Abstract: Multiband dipole antennas connected to a coaxial feeder are usually not balanced and are not operated at maximum efficiency. In the present invention pairs of capacitors are connected at the feed point of respective half-wave dipoles, associated with different frequency bands to reduce these deficiencies. A similar technique is useful for single band half-wave dipoles and allows unbalanced multiband ground plane antennas to be constructed.

Abstract: A one-piece array antenna folded dipole radiating element is formed from a wide, thin conductor. This element is suitable for attachment to a microstrip or other feed circuit. The radiation element includes a folded dipole portion, a balanced transmission line portion and may include a balun portion. These various portions are formed by providing an appropriately shaped slot or aperture in the thin conductor.

Abstract: This disclosure is concerned with a linear antenna array mounted on a conductive longitudinal boom, as in a Yagi-type array or the like, having a plurality of assymmetrical transversely extending folded half dipoles and linear extensions thereof disposed at successive longitudinally spaced locations along the boom, with the folded half dipoles of successive antennas extending from opposite sides of said boom.