Abstract: A base, a spool, and an antenna structure coupled to the spool has ends that are affixed to the base. The antenna structure is wound about the spool in a stowed state, and unwound to form a loop antenna in the deployed state. The antenna structure may be a bistable composite tape with a cross-sectional curvature and having one or more antenna conductors embedded therein. A storage containment device holds the antenna structure in the stowed state. When in the stored state, the antenna structure generates a strain force against the spool biased to unwind and deploy the antenna structure to form a loop antenna when released. Another embodiment adds a second spool rotating in a direction opposite the first to achieve either state. A further embodiment uses two loop antennas by winding two antenna structures around two pairs of spools, respectively.

Abstract: A spiral antenna apparatus utilizes a noise suppression sheet that is interposed between the spiral antenna element and its ground plane. The noise suppression sheet permits an extremely compact spiral antenna apparatus while lessening antenna performance degradation.

Abstract: A re-reconfigurable built-in antenna of a portable terminal is provided. The antenna includes an antenna radiator having a feeding pad electrically connected to a feeding portion of a main board of the terminal and at least one ground pad disposed in a position different from that of the feeding pad for selectively establishing an electrical connection to a ground portion of the terminal, and a switching element, commonly connected to the at least one ground pad of the antenna radiator, for selectively establishing an electrical connection to the ground portion by a switching operation. The antenna radiator changes a shape of the antenna radiator by using the selective electrical connection of the ground portion so as to have various operational frequency bands and radiation properties.

Abstract: An RFID transponder antenna has a carrier substrate and an auxiliary substrate. The carrier substrate is provided with a contact point for a first connection to an integrated circuit, and a first conductor path including at least two coil turns. A first end of the path forms a contact terminal for a second connection to the integrated circuit. The other end forms a connection point for an electrical connection to a second conductor path. The second path on the auxiliary substrate forms a bridge over the coil turns. The second conductor path has one end connected to the contact point, and another end connected to the connection point providing a permanent connection between the auxiliary substrate and/or the first conductor path, and the carrier substrate and/or second conductor path; the permanent connection being formed at least at one point lying between both ends of the auxiliary substrate.

Abstract: The present disclosure relates to an expandable antenna for a security system that is installed within a wall. The security system may include a control unit. The control unit may include a casing that houses one or more internal components of the control unit and a radio-frequency (RF) communication module that is situated within the casing. The RF communication module includes an antenna connected that is exposed to the exterior of the casing. An expandable antenna connects to the antenna connector. The expandable antenna is fit through an aperture in a wall and is then expanded to an enlarged size within the gap of the wall.

Abstract: An antenna comprising a main arm comprising conductive material, wherein the main arm is connected to a signal feed, and a first coupling arm comprising conductive material, wherein the first coupling arm is electrically coupled to a ground, and wherein the first coupling arm is electrically coupled to the main arm across a first span of nonconductive material. Also disclosed is a mobile node (MN) comprising a signal feed, a ground, and an antenna comprising a main arm comprising conductive material, wherein the main arm is connected to the signal feed, and a first coupling arm comprising conductive material, wherein the first coupling arm is connected to the ground, and wherein the first coupling arm is electrically coupled to the main arm across a first span of nonconductive material.

Abstract: In a near field communication partner device (1) intended for the contactless transmission of digital data to be transmitted having a transmission circuit (2), the transmission circuit (2) comprises a modulation circuit (17) for the amplitude modulation of a carrier signal (CS), which modulation circuit (17) comprises a circuit stage (20, 20?) for producing a plurality of different resistance values (RW1, RW1?) that act on a signal output (TX1, TX2), which resistance values (RW1, RW1?) can be transformed, by means of a signal processing circuit (3) arranged to transform resistance values that belongs to the communication partner device (1), into transformed resistance values (RW2, RW2?), which transformed resistance values (RW2, RW2?) are responsible for damping a transmission coil (7) of the communication partner device (1) when modulated low-level carrier signal sections are generated in a modulated carrier signal.

Abstract: A communication device including a ground element, an antenna element and a switching unit is provided. The antenna element is substantially a loop antenna and includes a first part, a second part and a third part. The second part includes (N?1) bends for forming N connection sections. The third part includes (P?1) bends for forming P ground sections. The N connection sections are connected in series between a first end of a first ground section and the first part. A second end of an ith ground section is electrically connected to a first end of an (i+1)th ground section, i is an integer and 1?i?(P?1). A second end of a Pth ground section is electrically connected to the ground element, and a (P?1)th ground section includes at least one ground point. The switching unit is electrically connected between the at least one ground point and the ground element.

Abstract: A frequency reconfigurable antenna may include at least two antenna segments and a photonic crystal positioned between the at least two antenna segments. The photonic crystal may selectably electrically connect or isolate the at least two antenna segments with respect to each other based on a conductive state of the photonic crystal.

Abstract: A modular reconfigurable indoor antenna is disclosed. The antenna may include a bottom piece, a top piece, and a plurality of vertical members. The top piece may include an Ultra High Frequency (UHF) reception element. The plurality of vertical members may be disposed between the bottom piece and the top piece and coupled therewith. At least one of the plurality of vertical members may include a Very High Frequency (VHF) reception element.

Abstract: An antenna sheet is provided with a flexible substrate, and an antenna coil, which is connected to a terminal section of an external IC module having an IC chip and is arranged on the substrate. On the substrate, a storing section that stores at least a part of the IC module is formed.

Abstract: In a communication partner device (1) intended for the contactless transmission of digital data to be transmitted having a transmission circuit (2), the transmission circuit (2) comprises a modulation circuit (17) for the amplitude modulation of a carrier signal (CS), which modulation circuit (17) comprises a circuit stage (20, 20?) for producing a plurality of different resistance values (RW 1, RW 1?) that act on a signal output (TX1, TX2), which resistance values (RW1, RW1?) can be transformed, by means of a signal processing circuit (3) arranged to transform resistance values that belongs to the communication partner device (1), into transformed resistance values (RW2, RW2?), which transformed resistance values (RW2, RW2?) are responsible for damping a transmission coil (7) of the communication partner device (1) when modulated low-level carrier signal sections are generated in a modulated carrier signal.

Abstract: A communication apparatus is provided that includes an apparatus main frame, an antenna, and a connecting element that connects the antenna to the apparatus main frame and positions the antenna away from the apparatus main frame.

Abstract: A radio frequency communication device and method are disclosed. In one aspect, an RFID tag includes an adjustable antenna having a main segment and one or more additional segments that are short relative to the main segment; and the antenna is adjustable to electrically isolate one or more of the additional segments from the main segment. In another aspect, an RFID tag includes an antenna having a first section and a second section short relative to the first section; and the antenna is adjustable to disconnect the first and second sections from each other at a predetermined location. In a further aspect, an RFID tag includes an antenna having a first section and a second section; and the first section is adjustable to decrease the first length of the first section and the second section adjustable to increase the second length of the second section.

Abstract: There is provided an antenna for tuning a resonant frequency. The antenna includes a first and a second arms connected to the antenna feeding portion at a common end thereof. The second arm has each of the plurality of branches including a switch for selecting a length of an electrical loop formed by the second arm and an end of a ground plane, each of the switches is connected to the ground plane. A first resonant frequency performed by the first arm is higher than a second resonant frequency by the second arm when each of the switches is open, and the first resonant frequency is lower than a third resonant frequency by the second arm when one of the switches is selected to connect the second arm and the ground plane so that the length of the electrical loop is maximum.

Abstract: A compact electrically long antenna including a manual or computer remote controlled tuning system using switched electrical length capable of operation at high RF power levels. An electromechanical relay or other switch device provides remote control (by a parallel binary bit pattern over great distance) of radiating structures formed of series connected absolute binary sequence electrical length radiating elements in a main circuit loop having a total electrical length. These radiating structures are formed from individual elements, and sets of individual elements, insulated and isolated from each other. The binary controlled switch devices may unshort (connect) and short out (bypass) binary length elements in the main loop circuit. The electrical length of the main loop circuit can be set to a desired length, from a maximum total length of all binary length elements in series to a minimum length where all binary elements are shorted out and effectively bypassed.

Abstract: A radio frequency identification tag includes an antenna including a conductor pattern in a form of dipole, and connected to an integrated circuit chip of the radio frequency identification tag; an adjusting portion including at least one adjusting pattern connected to the conductor pattern to make the antenna compatible with an environment in which the antenna is used; and a marking portion at which directions for an adjusting operation using the adjusting portion is indicated.

Abstract: A radio frequency communication device and method for tuning an antenna attached thereto are disclosed. A radio frequency communication device is disclosed comprising 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 RF air coil transponder includes a rotatable carrier, such as a rigid reel. A coil is wound about the reel and at least one field influencing body for influencing the electric and/or the magnetic field within the coil is supported by the reel. The rigidity of the reel enables the coil to keep its form and guarantees precise distances between windings, especially when a winding machine forms the coil. Adjusting the angular position, shape, composition, size, and/or surface are of the body effects adjustment of the resonant frequency.

Abstract: Techniques for tuning an antenna to different operating frequencies are described. An apparatus includes a security tag with a substrate having a surface, a lead frame to mount on the surface and connect to an antenna, and an integrated circuit to connect to the lead frame. The antenna may be disposed on the surface, and may comprise a first antenna portion and a second antenna portion. The first antenna portion may connect to the first side and the second antenna portion may connect to the second side. The antenna may be tuned to an operating frequency by modifying a first length for the first antenna portion and a second length for the second antenna portion after the antenna portions are disposed on the surface.

Abstract: A single antenna element with a switchable extension may be used to change the size of the radiating surface and provide an antenna that has two or more separate center frequencies. The range of frequencies that may be tuned by the antenna is enhanced, while maintaining relatively low complexity tuning and matching circuitry. Switching for the extension is performed by a switching element that is located at the point of connection of the extension to the antenna element. A control line supplies a control signal to the switching element to enable and disable the extension. The control line is positioned in close proximity to the antenna element to enhance coupling between the antenna element and the control line.

Abstract: An antenna system and method for tire monitoring systems provides an elasticized substrate in combination with an antenna wire(s). The antenna cable can be wrapped around or otherwise applied to the elasticized substrate, preferably in a wave or sinusoidal configuration. When subjected to forces of external origin, the substrate can elongate while the antenna wire straightens. Upon release from the influence of such forces, residual spring forces within the elasticized substrate relax and return the substrate and the antenna cable carried thereby back to its original, optimal configuration. The pitch of the antenna material on the substrate may be customized to suit the needs of the particular tire and communication. The antenna may be sewn or woven into the elasticized fabric, helically wound around a core composed of such material, or attached in an alternative manner.

Abstract: A stub-loop based antenna doublet array having an offset feed and adjustably positioned stub-loops is provided that enables improved isolation of the horizontal versus vertical polarization characteristics from the impedance. Consequently, conventional VSWR adjustments or tuning can be accomplished without significantly impacting the polarization ratios or pattern.

Abstract: A scanner has plasma loop or plasma window antennas for selectively scanning for ID tags along distinct radials of the scanner. Scanner elements are made electromagnetically invisible to adjacent elements by removing power or lowering plasma densities so that the scanner elements do not interfere with its own operation. Activatable ID tags and a shipping container suitable for scanning with electromagnetic energy are also disclosed.

Abstract: An antenna for transmitting and receiving circularly polarized electromagnetic radiation which is configurable to either right-hand or left-had circular polarization. The antenna has a conductive plane and a closed conductive loop spaced from the plane. A signal transmission line is electrically coupled to the loop at a first point and a probe is electrically coupled to the loop at a spaced-apart second point.

Abstract: An antenna apparatus for receiving an electric wave, includes an antenna element for receiving an electric wave made from an elastic linear body of a loop shape which can be collapsed into a plurality of loops of a smaller diameter; a shape retaining member made from a sheet-shaped member such as cloth and spread inside the antenna element so as to maintain a spread state of the antenna element spread into a loop shape; and connection means for connecting the antenna element to an external device. Because the antenna element can be collapsed into a plurality of loops of a smaller diameter, the antenna apparatus can be reduced into a smaller size for carrying.

Abstract: A transmission line antenna (10) comprises first and second ends (14 & 16). Each end has a mounting portion defining a mounting height and an overlapping portion (18 & 20) defining an overlapping width. The overlapping portions are formed by bringing the ends around the ring and past each other, and are electrically connected together. The antenna is interconnected to a circuit board having a circuit impedance, and the mounting height and overlapping width are configured such that the antenna impedance matches the circuit impedance.

Abstract: In a multiple loop antenna comprising a combination of a plurality of loop antennas, at least one factor among the diameter of each loop antenna, the number of turns thereof, the direction thereof, the effective permeability thereof, the relative values of electric currents of loop antennas and the phase difference of electric currents is controlled in such a way that the magnetic field intensity within the range extending from the multiple loop antenna to the distance of transmission wavelength of the multiple loop antenna decreases in inverse proportion to the n-th power (n>3) of the distance from the multiple loop antenna. This makes it possible to obtain a multiple loop antenna that has a high-intensity magnetic field within the predetermined communication zone but can steeply decrease the magnetic field intensity according to an increase in distance from the antenna and surely control the magnetic field intensity to be not greater than a stated value on the outside of the communication zone.

Abstract: A selective calling receiver comprises two separate bands having an antenna circuit for tuning incorporated therein. The first band has a first antenna and tuning capacitors incorporated therein and stoppers formed and arrayed on the outer surface thereof. Predetermined points are provided to the first antenna, providing different effective antenna lengths, respectively. The respective stoppers are provided with electrodes which are connected to the predetermined points of the first antenna through the tuning capacitors, respectively. The second band has a second antenna and a hook. The hook can be engaged with a selected one of the stoppers of the first band depending on the user's wrist thickness. The hook comprises a conductor electrically connected to the second antenna. When engaged with a selected one of the stoppers, the hook brings into electrical contact with the corresponding electrode to form the antenna circuit.

Abstract: The antenna circuit and wrist radio instrument of the present invention compensates for slippage in the resonance frequency of antenna circuits caused by such as the wrist thickness of the person wearing them, and by being worn on the wrist and then not worn, and can always tune to a set frequency. Accordingly, the present invention is one that can automatically receive a set frequency signal stably and with a set sensitivity, with no need for special adjustments.

Abstract: An antenna (10) capable of receiving signals of various frequencies includes a series of superconducting antenna segments and decouplers disposed between each adjacent pair of antenna segments for selectively decoupling at least one antenna segment from the antenna (10) in response to the frequency of the signal received.

Abstract: A reactance buffer maintains a substantially constant reasonant frequency for an adjustable size loop antenna having first and second antenna segments. Each segment has first and second ends, the first ends being coupled to a receiver, and the second ends providing loop size adjustment. The reactance buffer comprises a reactance buffer input coupled to the second end of the first antenna segment. A plurality of taps are linearly disposed along a longitudinal axis of the first wristband section, and has a predetermined length between the outermost taps corresponding to the loop antenna size adjustment required. The taps provide selectable reactance buffer outputs for coupling to the second end of the second antenna segment. A plurality of reactance elements are arranged non-serially and couple the reactance buffer input to each of the plurality of taps and provide a substantially constant reactance measured between the reactance buffer input and each of the plurality of taps.

Abstract: A flexible antenna which operates to control both the reactance as well as the resistance of the antenna. A motorized pulley system attached between two supports is utilized to control the effectrive length of the wire as well as the height of the antenna above ground. The antenna includes a flat base portion suspended between the supports and leg portions extending from the base to the apex of the triangle close to the ground. The total length of the antenna as well as the height of the base portion above the ground is dependent upon the particular frequency which is to be transmitted or received.

Abstract: A coplanar antenna system having a single-coil loop antenna provides both transmit and receive functions. The antenna operates in a tuned mode during transmitting and an untuned mode during receiving. Dead zone and transformer effect problems are virtually eliminated. The transmitter is highly efficient and the receiver is impulse noise immune.

Abstract: A swept frequency theft detection system for detecting different resonant circuit targets which are resonant at different frequencies. The system comprises arrangements to generate swept frequency transmitter signals centered at different frequencies but which are swept in synchronism. Also provided are antennas formed by offset loops, with the loops of different frequency antennas lying along different diagonal lines.

Abstract: An antenna for a radio frequency transmitter or receiver carried in a wrist instrument is made as a loop of individually insulated multistrand wire embedded in an elastic fabric which comprises an expansion wristband for the wrist instrument, together with a capacitor embedded in a strap end. The multistrand wire is longer than the unstretched fabric and is either interwoven into the elastic field or sandwiched between two layers of fabric. The wire is folded back and forth in a serpentine shape in order to accomodate expansion. One end of the multistrand wire is soldered to a ground connection clip and the connection is embedded in a molded strap end. The other end of the multistrand wire is soldered to an insulated wire leading into the instrument case and to one lead of a capacitor. The other lead of the capacitor is soldered to a ground connection clip and all connections, as well as the capacitor are embedded in the other molded strap end.

Abstract: This invention is a collapsible two element cubical quad antenna consisting of two separate four member antenna elements. One end portion of each antenna element converges at a vertex and the other end portion of the antenna element describes a square. The axis of the vertex of one antenna element is positioned opposite to the axis of the vertex of the other antenna element. Thus, the end portions of both antenna elements, as positioned, describe a cubical figure. The end portion of both antenna elements serve as support points for antenna wires.

Abstract: The antenna structure possesses a multi-sided configuration with means being provided for equally changing the lengths of at least two sides facing each other to thereby adjustably vary the physical size of the antenna. A parasitic reflector having a similar configuration and means for adjustability is positioned a predetermined distance behind the antenna proper for increasing the gain of the antenna structure.