Abstract: A magnetic field focusing assembly includes a magnetic field generating device configured to generate a magnetic field, and a split ring resonator assembly configured to be magnetically coupled to the magnetic field generating device and configured to focus the magnetic field produced by the magnetic field generating device.

Abstract: A planar antenna structure is provided. The planar antenna includes a dielectric substrate, a ground plane, a first conductive pattern and a second conductive pattern. The dielectric substrate has a first surface and a second surface. The ground plane is on the second surface of the dielectric substrate. The first conductive pattern is on the first surface of the dielectric substrate, coupled to a feeding line. The second conductive pattern is on the second surface of the dielectric substrate, coupled to the ground plane. The first and second conductive patterns are coupled to serve as cascaded right- and left-handed transmission lines. The first and second conductive patterns include: a first lumped equivalent circuit of the right-handed transmission line; and a second lumped equivalent circuit of the left-handed transmission line, cascaded with the first lumped equivalent circuit, wherein the right- and left-handed transmission lines have electrical lengths with opposite signs respectively.

Abstract: One embodiment of the invention relates to an antenna providing a tunable resonant frequency within a low frequency band and further providing a high resonant frequency, the antenna comprises a first radiating structure of a first effective electrical length, a second radiating structure of a second effective electrical length having a fractional integer relationship to a wavelength related to the high resonant frequency and a variable reactance element connecting the first and the second radiating structures, wherein varying a reactance of the variable reactance element tunes the antenna within the low frequency band.

Abstract: An antenna device includes an antenna and a transmission element. The antenna includes a grounding element and a radiating element. The radiating element is connected to the grounding element and is provided with a plurality of spaced apart feeding portions. The transmission element is connected selectively to one of said feeding portions. When the transmission element is connected to one of the feeding portions, the radiating element operates in a distinct frequency.

Abstract: An antenna system is disclosed that includes a base section to which a signal connector may be attached, and a radiating section distal from said base section. The radiating section includes a flexible electrically conductive material and an adjustment system for changing a length of the electrically conductive material responsive to a control signal.

Abstract: An antenna having a band rejection filter. The antenna includes: a radiator formed of a single plate, a grounding part formed of a single plate, a dielectric substrate including a surface on which the radiator is attached and another surface on which the grounding part is attached, and the band rejection filter connected to an end of the radiator. The band rejection filter includes a first capacitor connected to a signal line in parallel, a resonator including an end connected to the first capacitor in parallel and another end grounded, and a second capacitor including an end connected to the first capacitor in series and another end connected to the radiator in series. The resonator includes an inductor and a third capacitor connected to the inductor in series. As a result, the antenna may remove a frequency lower than an ultra wide band pass.

Abstract: Even though an antenna apparatus is low profile to have a height of not more than 70 mm, sensitivity is maximally suppressed from being deteriorated. In an antenna case 10 projecting from a vehicle in a height of not more than 70 mm, an antenna circuit board 30 on which an antenna pattern is formed is uprightly arranged and an amplifier circuit board 34 which amplifies a received signal output from the antenna circuit board 30 are housed. In the antenna circuit board 30, an antenna coil to resonate the antenna pattern in an FM waveband is inserted between the antenna pattern and a feeding point. Therefore, a low-profile antenna pattern having a length which is about 1/20 a wavelength of an FM broadcast resonates the FM band.

Abstract: A radio frequency identification device including a substantially planar surface. Surface has a longitudinal axis and lateral axis. A plurality of discrete longitudinally spaced laterally elongate conductive dipole elements is mounted to surface. In the present embodiment these elements include a director element, a reflector element, and a driven element that is positioned intermediate of the director element and the reflector element. A radio frequency identification chip is conductively attached to driven element.

Abstract: A plurality of conductive strip elements compose multilayer loading structures on top and bottom surfaces of a dielectric transmission substrate, by which a part of intra-substrate transmission components of a electromagnetic wave are leaked out of the surfaces. Each multilayer loading structure includes a first conductive strip group of conductive strip elements within a first plane, and a second conductive strip group of conductive strip elements within a second plane, and the first and second conductive strip groups are formed to be capacitively coupled to each other. In each of the first and second conductive strip groups, the conductive strip elements are placed at intervals of a distance of a quarter or less of a reference adjacent distance, where the reference adjacent distance is defined as a distance for generating spatial harmonics of the electromagnetic wave on the surfaces of the dielectric transmission substrate.

Abstract: A test system for adjusting a wireless communication device by impedance loading features includes a power supply for generating a plurality of voltages, a test fixture coupled to the power supply for generating impedances corresponding to a plurality of impedance loading areas, a test equipment coupled to a test point of the wireless communication device via the test fixture for measuring a plurality of radio frequency characteristic sets of the wireless communication device, and a decision device coupled to the test equipment for determining an optimal impedance loading area of the wireless communication device according to the plurality of radio-frequency characteristic sets.

Abstract: The present tuning circuit for a trap antenna having a plurality of traps tuned to a predetermined frequency comprises a coil in which a conductive compensation section is electrically coupled to one end of the coil and a conductive tuning section is electrically coupled to the other end of the coil. A pair of rods electrically coupled to the tuning section extend in opposite directions therefrom, whereby the adjustment of the rods and the coil allow the tuning circuit to be operable at a desired resonant frequency. To prevent the detuning of the trap to which the tuning circuit is being attached, the dimension of the compensation section may be adjusted to enable the trap antenna to be operable at both its predetermined frequency and the desired resonant frequency established by the tuning circuit.

Abstract: An antenna may be formed from conductive regions that define a gap that is bridged by shunt inductors. The inductors may have equal inductances and may be located equidistant from each other to form a scatter-type antenna structure. The inductors may also have unequal inductances and may be located along the length of the gap with unequal inductor-to-inductor spacings, thereby creating a decreasing shunt inductance at increasing distances from a feed for the antenna. This type of antenna structure functions as a horn-type antenna. One or more scatter-type antenna structures may be cascaded to form a multiband antenna. Antenna gaps may be formed in conductive device housings.

Abstract: A Radio Frequency (RF) structure services an antenna having a characteristic impedance and includes a differential Power Amplifier (PA), a differential Low Noise Amplifier (LNA), and a balun transformer. The differential PA has a differential PA output with a PA differential output impedance. The differential LNA has a differential LNA input with an LNA differential input impedance. The balun transformer has a singled ended winding coupled to the antenna, a differential winding having a first pair of tap connections coupled to the differential PA output and a second pair of tap connections coupled to the differential LNA input, and a turns ratio of the single ended winding and the differential winding. The turns ratio and the first pair of tap connections impedance match the PA differential output impedance to the characteristic impedance of the antenna. The turns ratio and the second pair of tap connections impedance match the LNA differential input impedance to the characteristic impedance of the antenna.

Abstract: An antenna device capable of not only achieving multiple resonances and wideband characteristics but also achieving improvement of antenna efficiency and accurate matching at all resonant frequencies, and a wireless communication apparatus. In one example, an antenna device 1 includes a radiation electrode 2 to which power is capacitively fed through a capacitor portion C1, and additional radiation electrodes 3-1 to 3-3 branched from the radiation electrode 2. A distal end portion 2a of the radiation electrode 2 is grounded to a ground region 402, and is a portion at which a minimum voltage is obtained when power is fed. A capacitor portion C2 that is a portion at which a maximum voltage is obtained when power is fed is disposed in a proximal end portion 2b of the radiation electrode 2, and a variable capacitance element 4 which is grounded is connected in series with the capacitor portion C2.

Abstract: An antenna arrangement including: a coupling element, a conductive element; an extension element for electrically extending the conductive element and a reactive element. A method of creating an antenna arrangement including an antenna element having a first resonant frequency and a first bandwidth, a conductive element, an extension element, for electrically extending the conductive element, having a size and an inductor having an inductance value wherein the extended conductive element has a resonant mode having a second resonant frequency and a second bandwidth, the method including: selecting the size of the extension element, the inductance value and a position of the inductor to tune the resonant mode of the extended conductive element so that the second bandwidth in the region of the first resonant frequency is larger than the first bandwidth in the region of the first resonant frequency.

Abstract: Described is a technology by which an antenna circuit is modified by changing its loading element or elements to thereby provide a particular polar radiation/gain pattern. An antenna loading element is coupled to an antenna (e.g., a chip antenna of a mobile device, a printed copper monopole antenna, a meander line antenna, a Planar Inverted-F (type) Antenna (PIFA) or the like), and includes at least one segment that is not substantially parallel to the chip antenna. For example, in one implementation, the antenna element includes segments that are substantially orthogonal to a top-loaded chip antenna. The resulting antenna/antenna circuit modifies the polar radiation pattern, such that, for example, a mobile device can achieve more optimum gain when oriented for typical usage. One or more other segments may be bent to extend at another angle or angles to achieve a particular polar gain pattern.

Abstract: An apparatus based on composite right-handed or left-handed (CRLH) principles to provide a transmission line or antenna structure having a plurality of cells to which one or more feed ports are attached. The apparatus is based on an equivalent circuit Right-Hand (RH) series induction (LR) and shunt capacitor (CR), and Left-Hand (LH) series capacitor (CL) and induction (LL), in which effective permittivity (e) and permeability (m) of the structure are manipulated by the choice of CR, LR, CL, and LL. One embodiment describes mushroom antenna cells (1D or 2D array) in which vias extend up from a feed network on a ground plane through at least one dielectric region to each of a first plurality of conductive elements (plates or strips). Optionally, a second plurality of conductive elements are disposed between first and second dielectric layers to form metal-insulator-metal (MIM) capacitors to lower resonance frequency.

Abstract: An antenna unit has a first antenna operating at wireless telecommunication bands and a second antenna operating at wireless local area network bands. The first antenna has a first radiating conductor with a first feeding point defining opposite sides, a second, a third and a fourth radiating conductors extending from both sides of the first radiating conductor. A parasitic element defines opposite ends. One end of the parasitic element confronts the free end of the third radiating conductor. A trap circuit connects the fourth radiating conductor and the parasitic element. A second antenna has a third side, a fourth side and a stair-shape side. The connection of the sides of the second antenna forms a first protrusion with a second feeding point and a second protrusion confronting the first antenna. A slot is opened on the second antenna. A ground portion is spaced from the first radiating conductor and the first protrusion.

Abstract: Cavity antenna excited with one or several dipoles in a single piece, which has on the element that excites the cavity a metallic plate connected to earth and which allows the input impedance of the antenna to be adjusted as well as the reflections in the radome, by means of the adjustment of the distance with respect to the back wall of the cavity, avoiding through the connection to earth that the antenna becomes charged electrostatically. The cavity assembly and the metallic plate allow a broader bandwidth, moreover a simpler control is achieved in the adjustment of the level of crosspolar polarization, as well as of the decoupling between dipoles by modification in the shape of the metallic plate. The grouping of the antennas in an array is possible in an immediate manner with no need to alter the size or shape of the cavities or of the dipoles which excite said cavities.

Abstract: An antenna includes inductance elements that are magnetically coupled together, an LC series resonant circuit that includes one of the inductance elements and capacitance elements, and an LC series resonant circuit that includes another of the inductance elements and capacitance elements. The plurality of LC series resonant circuits are used to radiate radio waves and are used as inductances of a matching circuit that matches an impedance when a power supply side is viewed from power supply terminals and a radiation impedance of free space.

Abstract: An antenna having a plurality of resonant frequencies and including a ground plane having an edge; a feed point; a ground point; and an antenna track extending between the feed point and the ground point and comprising, in series connection, a first loop and a second loop wherein a least a portion of the first loop and a portion of the second loop are adjacent at least the edge of the ground plane.

Abstract: A system and method for optimally placing radio frequency identification (RFID) antennas. The system varies the placement of RFID tag and interrogator antennas with respect to each other and a stationary object or objects. A signal generator sends a known reference signal to the one or more RFID interrogator antennas. The signal is received by the one or more RFID tag antennas and is displayed upon an oscilloscope, spectrum analyzer or other multipurpose signal measuring device. By this method, the system finds the optimal placement of the antennas with respect to each other and the object or objects.

Abstract: A system having a UHF RFID transceiver is adapted to communicate exclusively with a single electro-magnetically coupled transponder located in a predetermined confined transponder operating region. The system includes a near field coupling device comprising a plurality of lines connected in parallel with an unmatched load. The near field coupling device may be formed, for example on a printed circuit board with a plurality of electrically interconnected traces and a ground plane. The system establishes, at predetermined transceiver power levels, a mutual electro-magnetic coupling which is selective exclusively for a single transponder located in a defined transponder operating region. Also included are methods for selective communication with the transponder in an apparatus such as a printer-encoder.

Abstract: A Radio Frequency (RF) structure services an antenna having a characteristic impedance and includes a differential Power Amplifier (PA), a differential Low Noise Amplifier (LNA), and a balun transformer. The differential PA has a differential PA output with a PA differential output impedance. The differential LNA has a differential LNA input with an LNA differential input impedance. The balun transformer has a singled ended winding coupled to the antenna, a differential winding having a first pair of tap connections coupled to the differential PA output and a second pair of tap connections coupled to the differential LNA input, and a turns ratio of the single ended winding and the differential winding. The turns ratio and the first pair of tap connections impedance match the PA differential output impedance to the characteristic impedance of the antenna. The turns ratio and the second pair of tap connections impedance match the LNA differential input impedance to the characteristic impedance of the antenna.

Abstract: A method of operating a distributed loaded antenna system including a monopole antenna is disclosed. The method includes the steps of providing a radiation resistance unit coupled to a transmitter base, providing a current enhancing unit coupled to the radiation resistance unit via a conductive midsection; providing transmission signal energy to the radiation resistance unit, and distributing the transmission signal energy through the current enhancing unit.

Abstract: The present invention provides apparatuses and methods for an antenna in a wireless receiving system. The antenna includes an opened segmented component that is electrically coupled to a printed circuit board and a capacitive top loaded component that provides a capacitive load. The vertical profile of the antenna may be reduced sufficiently so that the antenna may be internally located in the same enclosure as the printed circuit board. The capacitive top loaded component is situated away from a ground plane of a printed circuit board to reduce the capacitive coupling is reduced, and consequently the required voltage standing wave ration (VSWR) is maintained over a broad operating range. The capacitive top loaded component includes a closed shape that provides a capacitive load. In order to tune the antenna to operate with a desired characteristic (e.g., within a VSWR criterion), the closed shape may be modified.

Abstract: In one embodiment of the present invention, the antenna is punched out and formed from a front surface of a chassis. The antenna may be connected to a wireless device by a coaxial cable. The center conductor of the coaxial cable may be coupled to the feed point of the antenna and the shield of the coaxial cable may be terminated at the front edge of the chassis to reduce radio frequency radiation from the coaxial shield.

Abstract: A control device for an antenna matching circuit is configured to output an adjusting signal for changing impedance of an element in the antenna matching circuit based on change over time in signal power ratio of a reflected signal from the antenna matching circuit to an incident signal to the antenna matching circuit.

Abstract: In an exemplary aspect of the invention, an antenna is disclosed that includes a ground plane and a disk disposed adjacent to the ground plane. The disk has a perimeter. The antenna further includes a loading reflector having an underside. At least a portion of the underside is electrically connected to a portion of the perimeter of the disk. The loading reflector has a width at a widest point, and the width at the widest point of the loading reflector is larger than a thickness of the disk. The disk may be circular or elliptical. The ground plane may include a cavity, where the disk is disposed within an outer border of the cavity. When an elliptical disk is used, the cavity may also be elliptical. An elliptical cavity may have a parabolic surface.

Abstract: A radio frequency communication device and methods of testing and tuning an antenna attached thereto are disclosed. A radio frequency communication device comprises internal circuitry and an antenna having a plurality of antenna segments associated therewith. Each antenna segment is associated with the antenna in either series or parallel relation through at least one of a fuse and an antifuse. In testing and tuning, a comparison is made to indicate whether the antenna is too short or too long. If the antenna is too short, an antenna segment may be attached to the antenna by initiating an antifuse. If the antenna is too long, an antenna segment may be detached from the antenna by blowing a fuse. If it is indeterminate whether the antenna is too short or too long, an antenna segment may be either attached or detached, the test repeated, and the results of the repeated test compared with the prior test to determine whether the correct action was taken.

Abstract: An antenna assembly includes at least two active or main radiating omni-directional antenna elements arranged with at least one beam control or passive antenna element used as a reflector. The beam control antenna element(s) may have multiple reactance elements that can electrically terminate it to adjust the input or output beam pattern(s) produced by the combination of the active antenna elements and the beam control antenna element(s). More specifically, the beam control antenna element(s) may be coupled to different terminating reactances to change beam characteristics, such as the directivity and angular beamwidth. Processing may be employed to select which terminating reactance to use. Consequently, the radiator pattern of the antenna can be more easily directed towards a specific target receiver/transmitter, reduce signal-to-noise interference levels, and/or increase gain.

Abstract: A wide band mobile antenna assembly having a whip, a base defining a housing, an adaptor extending on top of the base above the housing, and a mounting element extending in the housing. The mounting element has two opposite PCB mounting side surfaces and two opposite coil mounting surfaces. A PCB is mounted on each of the corresponding PCB mounting side surfaces. A matching circuitry is integrated on the two PCBs. The matching circuitry has a conductor for connection to the whip when the whip is inserted in the adaptor, and a conductor for external cable connection. The matching circuitry has a series resonant network operatively connected to a parallel resonant network for increasing a bandwidth of the antenna assembly. The series and resonant networks each have a coil mounted to the corresponding coil mounting surface.

Abstract: A distributed loaded antenna system including a monopole antenna is disclosed. The antenna system includes a radiation resistance unit coupled to a transmitter base, a current enhancing unit for enhancing current through the radiation resistance unit, and a conductive mid-section intermediate the radiation resistance unit and the current enhancing unit. The conductive mid-section has a length that provides that a sufficient average current is provided over the length of the antenna.

Abstract: AN RF diversity antenna coupling structure includes a differential low noise amplifier, a differential power amplifier, a first switch coupled to a first antenna, a second switch coupled to a second antenna, a first transformer, a second transformer, a transformer balun. The first transformer includes a primary winding and a secondary winding, wherein the primary winding of the first transformer is operably coupled to a differential output of the power amplifier, and wherein the secondary winding of the first transformer has a desired output impedance. The second transformer includes a primary winding and a secondary winding, wherein the primary winding of the second transformer is operably coupled to a differential input of the low noise amplifier, and wherein the secondary winding of the second transformer has a desired output impedance.

Abstract: An antenna for a wireless device may be kept dynamically tuned to a desired center frequency to compensate for detuning which may be caused by environmental influences. A sensor provides a feedback signal to a controller to select an appropriate capacitance value from a variable capacitor to tune the antenna for the wireless device. The variable capacitor may comprise a plurality of fixed capacitors and MEMS switches arranged in parallel or may comprise a variable MEMS capacitor having a fixed lower plate and a flexible upper plate.

Abstract: A system and method for optimally placing radio frequency identification (RFID) antennas. The system varies the placement of RFID tag and interrogator antennas with respect to each other and a stationary object or objects. A signal generator sends a known reference signal to the one or more RFID interrogator antennas. The signal is received by the one or more RFID tag antennas and is displayed upon an oscilloscope, spectrum analyzer or other multipurpose signal measuring device. By this method, the system finds the optimal placement of the antennas with respect to each other and the object or objects.

Abstract: An antenna includes a dielectric substrate disposed on a ground conductor and first and second radiating conductors containing meandering lines that are symmetrically disposed on a surface of the dielectric substrate and whose lower ends are connected at a junction. A third radiating conductor is disposed between the first radiating conductor and the second radiating conductor and extends in a straight line along the symmetry axis of both the radiating conductors. A capacitive conductor is disposed on the dielectric substrate and is substantially parallel to the ground conductor. The upper ends of the first, second and third radiating conductors are connected to the capacitive conductor. Power of a frequency supplied to the junction causes the first and second radiating conductors to resonate while power of a higher frequency causes the third radiating conductor to resonate.

Abstract: A method for designing a high performance, small antenna that is matched to a required output impedance, does not require filtering, is simple and inexpensive to manufacture, and is easily integrable with an RF power amplifier- with minimum cost, minimum external components and minimum energy losses. The method includes finding a singular point (102) in the impedance vs. antenna geometrical dimension/wavelength ratio graph, the singular point (102) exhibiting a high very high positive reactance, setting the antenna geometry to match this point, and canceling the very high positive reactance (high inductance) resulting from this match by adding to the antenna a very small capacitance, preferably provided by at least one gap capacitor (202) The antenna is preferably a loop antenna (200), and both the antenna and the gap capacitor (202) (204) are preferably implemented by printing methods on printed circuit board or ceramic substrates. The antenna (200) may also be implemented in non-differential designs.

Abstract: An antenna includes a radiating ring element formed as a spherical sector or about a one-half wavelength circumference in natural resonance for obtaining uniform current distribution and enhancing the gain relative to the size of the antenna. A capacitive element, such as a gap, can be formed therein for forcing the radiating ring element to resonance. A variometer feeds the radiating ring element and is operative for varying feed impedance.

Abstract: An antenna for generating an electromagnetic field including several planar inductive cells parallel connected in an array and forming, in association with at least one capacitor, an oscillating circuit adapted to being excited by a high-frequency signal.

Abstract: There is disclosed an antenna exhibiting resonance over a broad frequency band or over a plurality of closely-spaced frequency bands, comprising a ground plane, a non-driven element affixed substantially perpendicular to the ground plane, a driven element affixed substantially perpendicular to the ground plane and a horizontal conductor electrically connected between the driven and the non-driven elements and disposed substantially parallel to the ground plane. The non-driven and the driven elements further comprise periodic slow wave structures. The periodic slow wave structures are configured to provide a substantially constant propagation factor with respect to the applied signal frequency, such that the antenna exhibits broad resonance characteristics.

Abstract: A volumetrically compact and efficient antenna, with a high radiation resistance and low losses, that can be designed for any frequency, and which has a gain within 1 dB of that of a full-sized vertical monopole radiator or, in its horizontally polarized form, within 2 dB of that of a horizontally polarized half-wave dipole. One embodiment is a rectangle, with short radiators and long interconnecting wires, which has been folded back on itself in a manner that results in a square configuration (when viewed from the top) and brings the two radiating wires into close proximity. Only a single port need be fed. Linear loading sections, such as stubs, serrations and helically wound interconnecting wires can be used to electrically lengthen the antenna, while keeping physical dimensions small. Capacitive loading sections are also used. Two unequal-sized rectangular loops may be joined onto each other, to provide an additional radiating element.

Abstract: A monopole antenna for use with at least two wireless communication services, having a monopole element (10) disposed along a straight line (11) and connected with a roof capacitor (1) that is designed as a flat area, the area normal line (12) pointing in the direction of the straight line (11). The roof capacitor (1) has rotational symmetry, and is formed by flat ring structures (2) that are separated from one another by ring-shaped gaps (3), the structures being oriented concentric to the straight line (11). Reactance circuits (4) connect the ring structures (2) with one another so that they are active for a wireless communication service having the lowest frequency, and the outermost ring structure (2) is essentially ineffective for the wireless communication service having the next higher frequency, because of the high impedance of the reactance circuit (4).

Abstract: An RF antenna coupling structure includes a first transformer, a second transformer, and a transformer balun. The first transformer includes a primary winding and a secondary winding, wherein the primary winding of the first transformer is operably coupled to a power amplifier, and wherein the secondary winding of the first transformer has a desired output impedance corresponding to the operational needs of the power amplifier. The second transformer includes a primary winding and a secondary winding, wherein the primary winding of the second transformer is operably coupled to a low noise amplifier, and wherein the secondary winding of the second transformer has a desired output impedance corresponding to the needs of the low noise amplifier. The transformer balun includes a differential winding and a single-ended winding, wherein the differential winding is operably coupled to the secondary windings of the first and second transformers and the single-ended winding is operably coupled to an antenna.

Abstract: A broadband loaded antenna and matching network with related methods for design optimization are disclosed. The loaded antenna structures may preferably be either monopole or dipole antennas, but the particular methods and techniques presented herein may be applied to additional antenna configurations. The load circuits positioned along an antenna may comprise parallel inductor-resistor configurations or other combinations of passive circuit elements. A matching network for connecting an antenna to a transmission line or other medium preferably includes at least a transmission line transformer and a parallel inductor. Various optimization techniques are presented to optimize the design of such broadband monopole antennas. These techniques include implementation of simple genetic algorithms (GAs) or micro-GAs. Component modeling for selected components may be effected through either lumped element representation or curved wire representation.

Abstract: A combination antenna arrangement is provided for at least two wireless communication services, wherein a closely tolerated directional diagram is configured for the first wireless service, in a frequency range assigned to it. Antenna conductor parts are provided only for the function of the additional wireless communication services, and are radiation-coupled with the antenna assigned to the first wireless communication service. The conductor parts are divided into segments forming interruption points designed to be smaller than ? ? for this first wireless service. The interruption points are bridged by low-loss, frequency-dependent reactance circuits (8), in order for the combination antenna arrangement to function. These circuits possess a sufficiently high impedance in the frequency range of the first service and an impedance that is predetermined for proper functioning for the frequency range of the frequency range of the additional communication services.

Abstract: A multi-resonant antenna device includes an antenna element and an LC parallel resonance circuit making the antenna element resonate in a plurality of frequency bands, and the LC parallel resonance circuit includes a T-type circuit or PI-type circuit including an inductance element, acting as a shunt element, and capacitance elements, which prevent the impedance from becoming infinite in a certain frequency band. In this way, a drop, that is, a notch portion, in the frequency characteristic causing deterioration of the gain can be eliminated.

Abstract: The antenna includes four elements excited with equal amplitudes but with a relative phase difference of 0°, ?90°, ?180°, and ?270°. Each element includes a vertical and horizontal portion. An RF trap filter is located within the horizontal portion so that the antenna provides good gain coverage at all three frequency bands of a modernized global positioning system.

Abstract: There is disclosed a meanderline loaded antenna formed by applying a conductive ink or other conductive material to a flexible substrate. The substrate is then shaped by removing regions and folding other regions along perforated or scored lines to fit the antenna within the available space of a wireless device. In lieu of folding regions of a planar substrate to form a three-dimensional structure, the substrate can be vacuum formed over a mandrel after the antenna elements have been formed thereon. The antenna can also be formed by printing on existing enclosure surfaces of a wireless device or on the surfaces of components within the device. Thus the advantages offered by a meanderline antenna where the effective electrical length is greater than the actual physical length are achieved in conjunction with a space-saving physical structure for the antenna.

Abstract: A wideband meander line loaded antenna is configured to be flush mounted to a conductive surface serving as a ground plane by embedding the meander line components within a conductive cavity surrounded at its top edge by the ground plane. The antenna thus looks out of a cavity recessed in the surface. By permitting flush mounting the meander line antenna, not only can the antenna dimensions be minimized due to the use of the meander line loaded antenna configuration, but in aircraft applications no part of the antenna exists above the skin of the aircraft, thereby to minimize turbulent flow. Moreover, when adapted to wireless handsets or laptop computers, the depth or thickness of the unit need not be increased when providing a wideband antenna, thus to minimize the overall dimensions of the device.