Abstract: A variable type antenna matching circuit includes an antenna, shape change detecting section, transmission/reception radio section, and variable type antenna matching section. The shape change detecting section detects a change in the shape of the housing of a portable terminal. The transmission/reception radio section transmits and receives signals. The variable type antenna matching section changes the input impedance between the antenna and the transmission/reception radio section in accordance with an output signal from the shape change detecting section.

Abstract: A monopole antenna having a ground plane, a vertically extending feed line passing through a feed hole in the ground plane, a top hat in the shape of a disk connected to the feed line, the top hat being spaced from and extending over at least a portion of the ground plane, and a matching network disposed in a space between the top hat and ground plane, the matching network being arranged to effectively extend the feed hole in the ground plane. Such an antenna structure improves antenna bandwidth without increasing antenna volume or requiring external matching circuitry.

Abstract: An antenna system for transmitting and receiving, in association with a radio device that develops an H-field and an E-field corresponding to a radio frequency power signal having a voltage and a current, the voltage having a phase relationship to the current. The antenna system includes a Hertz-type radiating element. A phasing and matching circuit is electrically coupled between the Hertz-type radiating element and the radio device. The phasing and matching circuit adjusts the phase relationship between the voltage and the current of the radio frequency power signal so that the H-field and the E-field are in nominal time phase. This enhances the performance of all of the antenna parameters in addition to allowing reduction in size.

Abstract: A device for matching an antenna impedance in a portable radio telephone having transmission and receiving circuits, a foldable casing enclosing the radio, the foldable casing movable between an unfolded position and a folded position, an antenna movable between an extracted position from the foldable casing and a retracted position into the foldable casing includes means for sensing whether the foldable casing is in the unfolded position and for sensing whether the antenna is in the extracted position, and for providing a sensing signal in response thereto, and means for matching an impedance of the antenna and an impedance of the radio in response to the sensing signal, thereby making an optimal matching of impedances between the antenna and the radio according to the states of the folder casings and the antenna, and according to the transmission/reception mode.

Abstract: A multistage voltage multiplying circuit for single chip passive RF tags is provided, wherein the parasitic capacitance of the diodes of each stage of the voltage multiplying circuit is much less than the parasitic capacitance of the diodes of the preceding stage.

Abstract: A circuit arrangement for phase modulation in an input circuit of a backscattering transponder includes a varactor and at most one capacitor connected in series between two antenna terminals, as well as a varactor control arrangement applying a control voltage to the varactor to selectively vary the capacitance thereof. One of the antenna terminals is connected directly to one of the varactor terminals without a capacitor therebetween. The other antenna terminal is connected either directly or through a capacitor to the other varactor terminal. One antenna terminal and/or one varactor terminal can be grounded. A DC-decoupling capacitor can be connected between a transponder circuit unit or a circuit ground and the common junction of the antenna terminal with the varactor terminal. The circuit arrangement is simple, economical, and uses minimal chip area by omitting further capacitors between the antenna terminals.

Abstract: The present invention provides for low loss tunable matching circuits at rf frequencies. Ferro-electric materials are used to produce low loss tunable capacitors and inductors for use in matching circuits.

Abstract: In an antenna matching circuit including a parallel resonant section connected to a radiation element constituting an antenna, the parallel resonant section includes a series resonant portion composed of an inductance component and a capacitance component. The series resonant portion realizes antenna matching and band widening. The parallel resonant section can be inserted in a feeder line connected to the radiation element or inserted in a GND line connected to the radiation element.

Abstract: A portable receiver includes an antenna to which at least FM broadcast wave is inputted, a matching circuit to which the signal input to the antenna is supplied via minute resistance component, an FM receiver unit with the output of the matching circuit connected thereto, and an earphone connected to the output of the FM receiver unit. The antenna is formed from rigid metal, and its length is shorter than the quarter wavelength of the FM broadcast wave. The matching circuit is formed by reactance element having fine DC resistance. The impedance value of the resistance component as viewed via the resistance component from the matching circuit is nearly equal to the impedance of the matching circuit.

Abstract: A flexible substrate having a meandering antenna element and a matching circuit formed thereon is wound within an antenna cap and mounted on a terminal body. A rod-like antenna is arranged extensible within the flexible substrate. If the rod-like antenna is withdrawn, a linear antenna element is coupled by a capacitive coupling with the matching circuit formed on the flexible substrate. Also, if the rod-like antenna is returned into the terminal body, the capacitive coupling between the linear antenna element and the matching circuit is released, and the meandering antenna element is coupled by a capacitive coupling with the matching circuit on the flexible substrate.

Abstract: A diversity receiver includes a plurality of antennas, a receiving unit for receiving radio waves via the antennas, a phase adjuster disposed for each said antenna and connected thereto for adjusting a phase angle of a radio wave received by each of the antennas to a value to increase gain of each antenna to which the phase adjuster is not connected, and a switching unit, operative in response to a control signal indicating a selected antenna having a best reception state to receive an external radio wave, for connecting the selected antenna to the receiving unit, for disconnecting the selected antenna from the phase adjuster and non-selected antennas other than the selected antenna, and for connecting the non-selected antennas to the phase adjuster associated therewith. The phase adjuster is connected in a stage subsequent to the switching unit viewed from the antennas. This configuration provides a highly efficient diversity receiver.

Abstract: A signal sensing module senses an RF signal and produces one or more secondary signals representative of the RF signal. An impedance matching control module generates a control signal, based on the one or more secondary signals, which is indicative of an impedance mismatch between a load and a communications device. The control signal is then applied to at least one variable impedance device to adjust the impedance of an impedance matching network and thereby reduce the impedance mismatch between the load and the communications device. In an embodiment, the at least one variable impedance device is a barium strontium titanate, thin film, parallel plate capacitor. In other embodiments, other variable impedance devices such as other types of thin film capacitors or varactor diodes are used to adjust the impedance of the impedance matching network.

Abstract: A tunable antenna matching circuit is provided. The matching circuit includes a ferro-electric tunable component. A control signal is applied to the tunable component, changing the component's impedance. This changes the impedance of the matching circuit.

Abstract: A matching circuit for use with radio frequency identification tag antennas configured for modulated backscatter, the circuit including a stub circuit coupled to a detector diode and an antenna and sized and shaped to match a predetermined frequency. The stub circuit is also designed to couple to the antenna such that a resulting phase is seen at the output, preferably 180° from that seen at the input. In addition, the stub circuit is structured to perform as an antenna, thus increasing the sensitivity of the overall circuit and maximizing efficiency and performance.

Abstract: An antenna device comprises an antenna element formed in a sufficiently shorter length as compared with the wavelength of transmission or reception wave, a resistor, a matching circuit including at least a reactance element, and an output terminal connected to outside, which are connected in series in this sequence. As a result, an antenna device of smaller size and small loss is obtained.

Abstract: A dual band, higher and lower frequency range transducer with a circular coaxial waveguide feed is described having a first junction for connection of a lower frequency range outer waveguide of the coaxial waveguide feed to at least two rectangular or ridge waveguides offset from the longitudinal axis of the transducer and a second junction for connection of the at least two rectangular or ridge waveguides to a further waveguide. A third junction is provided for connecting an inner waveguide of the coaxial waveguide feed to a higher frequency range waveguide. The transducer comprises at least first and second parts joined across a first plane substantially perpendicular to the longitudinal axis and including at least a portion of the higher frequency range waveguide extending within the first plane of the join. A seal such as an “O” ring seal may be placed easily in the plane of the join thus preventing moisture ingress.

Abstract: A tunable dual band antenna system is disclosed. The system includes a transceiver, a matching network and an antenna. The matching network is operable to tune the antenna to the transceiver at both a first and second frequency. Accordingly, the matching network has a variable capacitor, an inductor and a second capacitor. The value of the variable capacitor is chosen to tune the antenna at the first frequency and the second frequency such that the system can be used to transmit and receive electromagnetic energy over two bandwidths. The values of the variable capacitor, the inductor, and the second capacitor are chosen to minimize the standing wave ratio of the system at both the first frequency and the second frequency.

Abstract: A variable type antenna matching circuit includes an antenna, shape change detecting section, transmission/reception radio section, and variable type antenna matching section. The shape change detecting section detects a change in the shape of the housing of a portable terminal. The transmission/reception radio section transmits and receives signals. The variable type antenna matching section changes the input impedance between the antenna and the transmission/reception radio section in accordance with an output signal from the shape change detecting section.

Abstract: An antenna arrangement comprises a patch conductor (102) supported substantially parallel to a ground plane (104) and a feed conductor (106) connected to the patch conductor. Such an arrangement is similar to a conventional Planar Inverted-F Antenna (PIFA), but lacks the additional grounding conductor connected between the patch conductor and the ground plane in known PIFAs. Elimination off this grounding conductor enables matching to be performed by external circuitry, thereby enabling a better match to be achieved and enabling similar performance to conventional PIFA antennas to be achieved from a reduced volume. These advantages are particularly apparent for dual-band (or multi-band) operation, where the use of a dual-band matching circuit allows a much smaller end less complex antenna to be used.

Abstract: A system and a method for providing a global positioning system (GPS) enabled antenna system are provided. The GPS enabled antenna may be used, for example, on a wireless communications device such as a wireless handset. The wireless communications device may include a switching module that can selectively switch communications signals between the antenna and one of a plurality of communications band circuits. A respective impedance matching circuit may be provided between the switching module and particular communications band circuitry to match or to tune the antenna to the particular communications band circuitry.

Abstract: Matching circuit for radio antenna that functions on a two-frequency band which are spaced approximately at a distance of one octave, wherein the upper band is broad. For instance, the first frequency band may be 890-940 MHz and the other band 1710-2200 MHz. The radiator may be a dipole or a monopole over the earth plane, whose bandwidth is sufficient for the first band. The larger bandwidth for the second band is obtained with a transmission circuit that moves and forms the frequency curve stepwise in the Smith chart. When necessary, the matching circuit includes a broadband Balun transformer in addition to said matching circuit.

Abstract: A broadband impedance matching integrated circuit apparatus comprising an alternating current ground plane, a direct current ground plane positioned proximate to the alternating current ground plane, a first conductive transmission line positioned a distance from the alternating current and direct current ground planes, a dielectric material layer with a thickness positioned on the first conductive transmission line, a second conductive transmission line positioned on the dielectric material layer wherein the first and second conductive transmission lines are electrically interconnected to behave as an electromagnetically coupled tapped autotransformer.

Abstract: An antenna device is disclosed, which is intended for a portable radio communication device. The communication device includes a signal generating component having a signal output, said output defining a signal generating circuit impedance. The antenna device includes a substantially planar conductor having an associated impedance and preferably extending in a first dimension greater than approximately one-quarter of a predetermined operational wavelength. The antenna device further includes a matching network which is coupled to the signal generating output. The matching network having a substantially planar dielectric substrate and a conductive meander element and a conductive trace element, wherein said matching network transforms the impedance of the signal generating component to approximate the impedance of the planar conductor element.

Abstract: A signal sensing module senses an RF signal and produces one or more secondary signals representative of the RF signal. An impedance matching control module generates a control signal, based on the one or more secondary signals, which is indicative of an impedance mismatch between a load and a communications device. The control signal is then applied to at least one variable impedance device to adjust the impedance of an impedance matching network and thereby reduce the impedance mismatch between the load and the communications device. In an embodiment, the at least one variable impedance device is a barium strontium titanate, thin film, parallel plate capacitor. In other embodiments, other variable impedance devices such as other types of thin film capacitors or varactor diodes are used to adjust the impedance of the impedance matching network.

Abstract: An antenna is provided to improve the gain and to eliminate various negative effects caused by a surrounding environment in which the antenna is mounted, such as the effects caused by neighboring metal plates and the like, while providing an antenna structure to facilitate its assembly into various communication devices. The antenna emitting radio waves at a center frequency has an antenna main body and a grounding line section connected to the ground-side of the coaxial cable for supplying power to the antenna main body. The grounding line section starts from a reference point and extends in a loop so as to surround the antenna main body, and portions of the conductor line are severed so as to provide a first end terminal and a second end terminal so that the length of the conductor line from the reference point to the first end terminal corresponds to one quarter of a wavelength of the center frequency or its integral multiple.

Abstract: An antenna is provided which can reconcile a low antenna resonance frequency and broadband frequency characteristics, while attaining stable impedance characteristics and enhanced design flexibility. A conductive plate is coupled to a conductive base plate via a first metal lead. A voltage is applied to the conductive plate from a supply point via a second metal lead. A conductive wall is electrically coupled to the conductive plate at one end thereof. An electromagnetic field coupling adjustment plate is electrically coupled to the other end of the conductive wall. The electromagnetic field coupling adjustment plate is disposed so as to leave a predetermined interspace between itself and the conductive base plate, thereby creating a capacitor in conjunction with the conductive base plate.

Abstract: A radio frequency transponder assembly comprises a passive transponder and an antenna with a matching circuit comprising an inductor and a capacitor which are formed integrally with the antenna components. The antenna is a dipole with legs formed from wire or foil strips, in which case the inductor and capacitor are formed from same material as the antenna legs. The values of the inductor and capacitor are calculated to match the antenna impedance to the equivalent load of the transponder circuit as seen via the power rectification circuits of the transponder.

Abstract: A dual-band antenna assembly configured to be mounted on a dielectric substrate such as an automobile window glass. The dual-band antenna assembly is adapted to transmit and receive signals in two distinct frequency bands, particularly the cellular frequency band, 800-900 MHz and the PCS frequency band 1.8 GHz. The antenna assembly is further configured to couple signals in either frequency band through the dielectric so that signals originating on a first side of the dielectric substrate may be coupled to the antenna-radiating element located on the opposite side of the dielectric substrate and signals received by the antenna on the second side of the dielectric substrate may be coupled through the dielectric to a mobile telephone located on the first side of the substrate.

Abstract: A signal sensing module senses an RF signal and produces one or more secondary signals representative of the RF signal. An impedance matching control module generates a control signal, based on the one or more secondary signals, which is indicative of an impedance mismatch between a load and a communications device. The control signal is then applied to at least one variable impedance device to adjust the impedance of an impedance matching network and thereby reduce the impedance mismatch between the load and the communications device. In an embodiment, the at least one variable impedance device is a barium strontium titanate, thin film, parallel plate capacitor. In other embodiments, other variable impedance devices such as other types of thin film capacitors or varactor diodes are be used to adjust the impedance of the impedance matching network.

Abstract: The invention relates to an active reception antenna comprised of a passive antenna component with a frequency-dependent effective length le. The output connections of this passive component are connected to the input connections of an amplifier circuit. The amplifier circuit consists of a field effect transistor and a low-loss filter circuit with an input admittance. The low-loss filter circuit is connected on its input to the source connection of the field effect transistor. On its output, the high-frequency reception signal is de-coupled, and the low-loss filter circuit is loaded with an effective resistance or conductance acting on its output.

Abstract: An antenna apparatus which has an antenna element (102) being mounted on a portable radio for receiving electric power from a feeding point (103) in the portable radio and matching in a predetermined frequency band and a matching circuit (104) for matching the impedance of the antenna element (102) and the internal impedance of the radio circuit (105). The matching circuit (104) has a match characteristic to conjugately match the internal impedance of the radio circuit (105) and the input impedance of the matching circuit (104).

Abstract: An antenna system for transmitting and receiving, in association with a radio device that develops an H-field and an E-field corresponding to a radio frequency power signal having a voltage and a current, the voltage having a phase relationship to the current. The antenna system includes a Hertz-type radiating element. A phasing and matching circuit is electrically coupled between the Hertz-type radiating element and the radio device. The phasing and matching circuit adjusts the phase relationship between the voltage and the current of the radio frequency power signal so that the H-field and the E-field are in nominal time phase. This enhances the performance of all of the antenna parameters in addition to allowing reduction in size.

Abstract: A signal sensing module senses an RF signal and produces one or more secondary signals representative of the RF signal. An impedance matching control module generates a control signal, based on the one or more secondary signals, which is indicative of an impedance mismatch between a load and a communications device. The control signal is then applied to at least one variable impedance device to adjust the impedance of an impedance matching network and thereby reduce the impedance mismatch between the load and the communications device. In an embodiment, the at least one variable impedance device is a barium strontium titanate, thin film, parallel plate capacitor. In other embodiments, other variable impedance devices such as other types of thin film capacitors or varactor diodes are be used to adjust the impedance of the impedance matching network.

Abstract: A signal divider/combiner (11) and method combines first and second frequency signals received by microstrip patch antennas (58, 48). A first transmission line stub (28) blocks the second frequency signals on the first signal receiving path, and a second transmission line stub (20) blocks the first frequency signals on the second signal receiving path providing increased signal levels at a receiver input (10). In one embodiment, the transmission line stubs are open-circuit stubs and are positioned a quarter-wavelength from a combining junction (12) formed from stripline transmission lines (14, 32, 50). The transmission line stubs (28, 20) also reduce radiation of the first frequency signal by the second antenna as well as radiation of the second frequency signal by the first antenna. In one embodiment, the first and second frequency signals are the L1 and L2 signals provided by the Global Positioning System.

Abstract: The present invention provides for low loss tunable matching circuits at rf frequencies. Ferro-electric materials are used to produce low loss tunable capacitors and inductors for use in matching circuits.

Abstract: In an antenna system for transmitting and receiving, in association with a radio device, electromagnetic radiation has an E-field component and an H-field component. The electromagnetic radiation corresponds to a radio frequency power signal having a current and a voltage at a radio frequency. The antenna system includes a first radiating element and a second radiating element, each comprising a conductive material. The second radiating element is spaced apart from, and in alignment with, the first radiating element. A phasing and matching network is in electrical communication with the first radiating element, the second radiating element and the radio device. The phasing and matching network aligns the relative phase between the current and the voltage of the radio frequency power signal so that the H-field component of the corresponding electromagnetic signal is nominally in time phase with the E-field component.

Abstract: An impedance matching means (3) according to the present invention is used with a printed wire board (PWB) antenna. The PWB antenna includes a PWB (1) having an upper side (11) and a lower side (12), and an antenna body (2) having a radiating portion (21), a feed portion (22), and a ground portion (23). A transmission cable is connected to the antenna body with its inner conductor soldered to the feed portion and its outer shield soldered to the ground portion. The matching means has a first conductive patch (5), which is electrically connected to the feed portion, and a second conductive patch (6), which may or may not be electrically connected to the ground portion. The first and the second conductive patches are disposed in parallel, one on the upper side and one on the lower side of the PWB, and thus sandwich a portion of the PWB therebetween.

Abstract: A tunable antenna matching circuit is provided. The matching circuit includes a ferro-electric tunable component. A control signal is applied to the tunable component, changing the component's impedance. This changes the impedance of the matching circuit.

Abstract: An LC parallel resonance circuit is connected in series with the power supply side of the antenna conductor portion. The antenna conductor portion is configured so as to resonate at a frequency slightly lower than the center frequency in the higher frequency band of two frequency bands for transmitting and receiving radio waves. The LC parallel resonance circuit is configured so as to resonate substantially at the center frequency in the lower frequency band for transmitting and receiving a radio wave and be capable of providing to the antenna conductor portion a capacitance for causing the antenna conductor portion to resonate at the center frequency in the higher frequency band. Thus, a circuit for changing the upper and lower frequency bands is not needed. Such a change-over circuit, which is complicated, causes problems in that the conduction loss increases, and the antenna sensitivity deteriorates.

Abstract: One matching circuit (8-2) comprises a transmission line (6b) of a predetermined electrical length and a parallel resonance circuit (5) connected in parallel with the transmission line. The resonance circuit has a resonant frequency f2 and a predetermined susceptance at a frequency f1 lower than the frequency f2. ANother matching circuit (8-1) comprises a transmission line (6a) of a predetermined electrical length and a capacitor element (b 3a) connected in series with the transmission line between an input terminal (2) of an antenna (1) and the matching circuit (8-2) so that the input impedence of the antenna at the frequency f2 may match the characteristic impedance of an external circuit (10).

Abstract: An antenna apparatus for providing wireless communication comprise a first antenna plate, a second antenna plate and a matched circuit. The matched circuit has a front line and a transferring line so as to be formed as an appropriate impedance between the first antenna plate and the second antenna plate, wherein one end of the transferring line is coupled to the front line forming a T shaped converging portion having a first feedback point and a second feedback point. The first antenna plate has an electrical foot connecting to the first feedback point and a ground foot connecting to the ground. Similarly, the second antenna plate has an electrical foot connecting to the second feedback point and a ground foot connecting to the ground.

Abstract: An antenna device including matching circuits corresponding to reflection coefficients of antenna elements determined by taking into account the couplings between the antenna elements occurring when the antenna elements are excited with corresponding excitation amplitudes and excitation phases at each of operational frequencies.

Abstract: A tunable dual band antenna system is disclosed. The system includes a transceiver, a matching network and an antenna. The matching network is operable to tune the antenna to the transceiver at both a first and second frequency. Accordingly, the matching network has a variable capacitor, an inductor and a second capacitor. The value of the variable capacitor is chosen to tune the antenna at the first frequency and the second frequency such that the system can be used to transmit and receive electromagnetic energy over two bandwidths. The values of the variable capacitor, the inductor, and the second capacitor are chosen to minimize the standing wave ratio of the system at both the first frequency and the second frequency.

Abstract: An apparatus and method for matching an antenna having a high or low impedance with a transceiver circuit having an impedance of 50 ohms. A multilayer substrate, such as one or more printed circuit boards, is provided and has the various components of a matching circuit formed on including a capacitor and an inductor. The components are formed on the substrate using printed circuit techniques. A radiating element is connected to the matching circuit. The radiating element may be a discrete antenna or may also be formed on the substrate.

Abstract: When the antenna is extended, the length of the ½&lgr; whip antenna 102 operates as an antenna thus causing only a negligible quantity of high-frequency currents to flow into the ground for the circuit board 108. When the antenna is housed, the entire length of a ¼&lgr; helical antenna 101 and a ¼&lgr; radial 109 operates as an antenna thus causing only a negligible quantity of high-frequency currents to flow into the ground for the circuit board 108. When the antenna is extended, the second contact 104 makes adjustments so that high-frequency electric signals from the ½&lgr; whip antenna 102 may be transmitted to the circuit board 108 and matching may be provided at the second matching section 106 when the antenna is extended.

Abstract: The present invention provides a miniature, built-in multi-band antenna which is suitable for use in future compact mobile terminals. According to exemplary embodiments, a built-in patch antenna is provided which includes patch elements of different sizes and capable of being tuned to different frequency bands. On each patch element is formed a slot which divides the patch element into sub-parts. Each sub-part of a patch element is structured so as to be resonant at a frequency in the same frequency band to which the patch element is tuned. As a result, a high efficiency, broad band, multi-band, and surface mountable low profile antenna can be realized.

Abstract: A matching network for coupling an OEM vehicle antenna to communications equipment operating at two different frequencies without any physical modification of the antenna mast and base. The network comprises a first transmission line section connected at one end to the antenna, a first stub tuner connected to the opposite end of the first transmission line section, a second transmission line section connected at one end to the junction of the first transmission line section and the first stub tuner, a second stub tuner connected to the opposite end of the second transmission line section, and a feedline connected to the junction of the second transmission line section and the second stub tuner for connection to the communications equipment operating at the two different frequencies.

Abstract: The present invention includes antenna connectors, antenna connecting devices, and antenna connecting systems. This invention also includes machines or electronic devices using these aspects of the invention.

Abstract: The present invention relates to an impedance-matching device of antenna units, and in particular to antenna-matching in small radio units. An impedance-matching device (16) is arranged in a radio equipment (10) having an antenna (12), between said antenna and a feeding unit, e.g. an output power unit, the impedance quotient of which units exceeding a factor 3. The invented impedance-matching (16) includes at least two quarter-wave transformers (18,20) connected in series, which consist of a dielectric material (28) having a dielectric coefficient &egr;, the value of which is exceeding a factor 10. The device may be made with dimensions so small that it may be integrated with the antenna to an antenna unit and despite the small dimensions, good frequency characteristics are achieved, such as good precision, easy tuning and sufficiently broad bandwidth.

Abstract: A bifilar coil construction is used for isolating radio signals picked up by a motor vehicle window heating element from the power supply circuit for the heating element. The coil construction has two separate windings (9,10) which are arranged bodily alongside each other. In one embodiment there is an inner cylindrical winding (9) within and in contact with an outer cylindrical winding (10), and a two part pot core (15,16) is clamped within and around the windings (9,10).