Abstract: A communication system is provided, including an antenna, a matching network coupled to the antenna, a controller configured to control the matching network, and a look-up table coupled to the controller. The look-up table includes characterization data according to frequency bands and conditions. The controller is configured to refer to the look-up table to determine optimum impedance for a frequency band selected under a condition detected during a time interval, and adjust the matching network to provide the optimum impedance.

Abstract: An electronic device may include an adjustable power supply, at least one antenna, and associated antenna tuning circuitry. The antenna tuning circuitry may be an integral part of the antenna and may include a control circuit and at least one tunable element. The tunable element may include radio-frequency switches, continuously/semi-continuously adjustable components such as tunable resistors, inductors, and capacitors, and other load circuits that provide desired impedance characteristics. The power supply may provide power supply voltage signals to the antenna tuning circuitry via inductive coupling. The power supply voltage signals may be modulated according to a predetermined lookup table during device startup so that the control circuit is configured to generate desired control signals. These control signals adjust the tunable element so that the antenna can support wireless operation in desired frequency bands.

Abstract: The present invention discloses an antenna impedance matching method which is used for adjusting an impedance of an antenna to match an impedance of a radio frequency (RF) integrated circuit (IC). The method comprises the following steps of: (1) providing an antenna matching IC; (2) obtaining a used frequency band of the RF IC, so as to obtain a frequency band signal; (3) adjusting an impedance of the matching IC according to the band signal, so that the antenna achieves impedance matching. In summary, the present invention uses the matching IC to instead of a traditional matching circuit, and according to the band signal of the RF IC to adjust and match the impedance of the IC, so as to change the resonance and impedance of the antenna, and to achieve the impedance matching.

Abstract: Methods for generating a look-up table relating a plurality of complex reflection coefficients to a plurality of matched states for a tunable matching network. Typical steps include measuring a plurality of complex reflection coefficients resulting from a plurality of impedance loads while the tunable matching network is in a predetermined state, determining a plurality of matched states for the plurality of impedance loads, with a matched state determined for each of the plurality of impedance loads and providing the determined matched states as a look-up table. A further step is interpolating the measured complex reflection coefficients and the determined matching states into a set of complex reflection coefficients with predetermined step sizes.

Abstract: An antenna arrangement comprising an input/output connection and a first and a second tuning network with different transfer functions. The arrangement additionally comprises an antenna and a switch for connecting the input/output connection of the arrangement to one of said tuning networks, with a second switch for connecting the antenna of the arrangement to the tuning network to which the input/output connection of the arrangement has been connected. The arrangement comprises a sensor for sensing a form factor of the arrangement or of an apparatus in which the arrangement is used, and said sensor can be used for influencing said first and second switches, so that a device which has been connected to the arrangement may be connected to the antenna via a tuning network optimal for the current form factor of the arrangement.

Abstract: An improved variable matching network for use in a multi-band, multi-mode communications device provides dynamic, fine-tune impedance matching based on current operational conditions associated with a given signal. In one embodiment, gross parameters are selected based on one or more of the operational conditions. Delta parameters are provided using an optimization algorithm based on one or more of the operational conditions. And the gross and delta parameters are combined to obtain overall matching parameters that dynamically fine-tune discrete matching circuitry.

Abstract: An electronic device includes an antenna, an RF circuit, and a matching circuit. The matching circuit is configured to provide variable impedance between the antenna and the RF circuit, wherein the matching circuit includes a first element having a first terminal and a second terminal, and wherein the first terminal is coupled to the antenna; a second element having a third terminal connected to the second terminal of the first element and a fourth terminal coupled to the RF circuit; a first tuning cell connected to the second terminal of the first element and the third terminal of the second element, and comprising a first tuning element, a second tuning element and a first control element, wherein the first control element determines whether to make a first node connected between the first and second tuning elements couple to a voltage level.

Abstract: A mobile communication device includes an antenna structure. The antenna structure includes a circuit board. A ground plane is disposed on the second surface of the circuit board and includes a first side edge and a second side edge. An antenna element is disposed on the first surface of the circuit board or placed near the circuit board, and includes a first operating band and a second operating band. A first inductively-coupled element is located near the first side edge of the ground plane, and includes a metal plate and an inductive element. The metal plate is electrically connected to the ground plane through the inductive element. The first inductively-coupled element generates a resonant mode at a specific frequency within the second operating band to reduce a surface current excitation on the ground plane and to reduce near-field E-field and H-field strengths of the mobile communication device within the second operating band.

Abstract: An apparatus including a cover defining an exterior surface of the apparatus and including a first conductive cover portion; an antenna, connected to a feed point and configured to operate in at least a first resonant frequency band; a first conductive member; a second conductive member; and wherein the first and second conductive members are configured to couple with the first conductive cover portion, the combination of the first and second conductive members and the first conductive cover portion are operable in a second resonant frequency band, different to the first resonant frequency band and are configured to be contactlessly fed by the antenna.

Abstract: Disclosed are apparatus and method for matching an antenna in a wireless terminal, which are tailored for easy control of impedance matching. A controller is configured to generate state information corresponding to states of the wireless terminal, and providing the state information to a Field Programmable Gate Array (FPGA) unit. The FPGA unit outputs an optimal Tunable Matching Network (TMN) adjustment value corresponding to the state information of the wireless terminal State information may include operating bands/protocols and modes discerning particular environmental conditions impacting electric fields, such as a hand-held condition.

Abstract: A space efficient multi-feed antenna apparatus, and methods for use in a radio frequency communications device. In one embodiment, the antenna assembly comprises three (3) separate radiator structures disposed on a common antenna carrier. Each of the three antenna radiators is connected to separate feed ports of a radio frequency front end. In one variant, the first and the third radiators comprise quarter-wavelength planar inverted-L antennas (PILA), while the second radiator comprises a half-wavelength grounded loop-type antenna disposed in between the first and the third radiators. The PILA radiators are characterized by radiation patterns having maximum radiation axes that are substantially perpendicular to the antenna plane. The loop radiator is characterized by radiation pattern having axis of maximum radiation that is parallel to the antenna plane.

Abstract: The present disclosure relates to wireless communication device antennas with tuning elements.

Abstract: A Radio Frequency (RF) device includes an adjustable antenna structure for coupling to a transmit/receive coupling module. The adjustable antenna structure includes an antenna and a plurality of transmission line elements. At least one of the plurality of transmission line circuit elements is selected, based on a transmission line characteristic signal, to form a transmission line circuit that is coupled to the antenna.

Abstract: A mobile wireless communications device may include a portable housing, and an antenna carried by the portable housing. The mobile wireless communications device may further include wireless communications circuitry carried by the portable housing and an adjustable impedance matching network coupled between the wireless communications circuitry and the antenna. An audio input transducer and an audio output transducer may be carried by the portable housing. The mobile wireless communications device may further include a controller carried by the portable housing and configured to determine an acoustic coupling between the audio input transducer and the audio output transducer. The controller may further be configured to adjust the adjustable impedance matching network based upon the determined acoustic coupling.

Abstract: A tag for a radio frequency Identification RFID system that comprises an open cavity with an integral load element. The load element is comprised of an impedance matching network and a load circuit. The load circuit contains one or more of an RFID transponder, microcontroller, capacitive sensor circuit, resistive sensor circuit, complex impedance sensor circuit, and an RF energy scavenging circuit in specific implementations. In various embodiments the tag includes reflector elements which enable the antenna structure to better tolerate the presence of nearby metal objects and provide electromagnetic gain.

Abstract: The invention relates to a controller for a radio circuit. The radio circuit comprises at least one variable impedance element coupled between an antenna and a received signal quality indicator generator. The controller is configured to receive a received signal quality indicator from the received signal quality indicator generator and to provide a control signal to the at least one variable impedance element. The control signal comprises a command to modify the impedance of the variable impedance element in accordance with the value of the received signal quality indicator.

Abstract: A wireless sub-surface soil sensor having a tunable antenna that can be optimized for transmission through various soils is disclosed herein. The wireless sub-surface sensor preferably also measures the moisture and salinity of a material. The wireless sub-surface sensor preferably includes a cover for protecting circuitry of the sensor. The wireless soil sensor is designed to be buried underground and to transmit to above ground receivers.

Abstract: A system for use with a transmitter and an antenna includes a radio frequency power detection portion, a tunable matching network, and a phase lock loop. The tunable matching network has a modifiable impedance to account for impedance mismatch between the transmitter and the antenna. The phase lock loop tunes the tunable matching network to modify the modifiable impedance.

Abstract: A broadband-operable impedance filter has capacitive elements of variable capacitance in the signal path, an inductive element in a parallel path connected in parallel to the signal path, and inductive elements in the ground path. The impedance filter allows communication in a first frequency band and the reception of HF signals in a second frequency band.

Abstract: An automatic tuning circuit for matching an antenna to a radio receiver. The automatic tuning circuit includes a tunable non-Foster circuit for coupling the receiver and the antenna; and sensing and feedback circuits for sensing the combined capacitance of the tunable non-Foster circuit and the antenna and for tuning the tunable non-Foster circuit to automatically minimize the combined capacitance of the tunable non-Foster circuit and the antenna.

Abstract: In one embodiment, the present invention provides a configurable ground plane for a matched antenna so that by configuring or changing the ground plane shape in a controlled manner, a change in the radiation pattern can be achieved such that the main beam of the antenna is steered in a particular direction, and a null in another direction. According to one aspect of the present invention, antennas such as monopole or patch antennas with a configurable ground plane of the present invention with a plurality of configurable sectors can be made to change in shape, size and conductivity. Such ground plane modifications can be used to select the direction of maximum gain away from a direction of interference, such in the case of tactical jamming. Likewise, the ground plane modifications can be used to steer the maximum directivity of an antenna in a desired direction for increased signal integrity.

Abstract: An antenna device of an embodiment includes: an antenna having a feeding point and an end portion apart from the feeding point, the end portion being an open end; a variable impedance matching circuit connected to the antenna at the feeding point; a probe placed in such a position that the distance from the end portion to a tip of the probe is equal to or shorter than one eighth of the wavelength corresponding to the maximum radio frequency used in the antenna device; and a controller that is connected to the probe, and controls the variable impedance matching circuit, based on an electrical signal measured with the probe.

Abstract: An embodiment of the present invention is an apparatus, comprising a tunable antenna including a variable reactance network connected to the antenna a closed loop control system adapted to sense the RF voltage across the variable reactance network and adjust the reactance of the network to maximize the RF voltage. The variable reactance network may comprise a parallel capacitance or a series capacitance. Further, the variable reactance networks may be connected to the antenna, which may be a patch antenna, a monopole antenna, or a slot antenna.

Abstract: According to one embodiment, an electronic apparatus includes an antenna, a switch circuit and a control circuit. The antenna is configured to have a first resonance frequency band and a second resonance frequency band. The switch circuit is connected between a feeder line and the antenna and configured to switch a resonance frequency band of the antenna from the first resonance frequency band to the second resonance frequency band in accordance with a control signal. The control circuit is configured to resonate with a transmission signal of the second resonance frequency band, which flows from a wireless communication module through the feeder line, and to generate the control signal by using energy which is obtained by the resonance with the transmission signal.

Abstract: An antenna interface circuit for a wireless communication device includes a tunable matching circuit that is coupleable to an antenna. The tunable matching circuit includes a variable impedance element having a variable impedance Ztune. The interface circuit further includes a fixed impedance element having a fixed impedance Zmeas, and a switch coupled to the fixed impedance element and configured to controllably switch the fixed impedance element into electrical communication with the tunable matching circuit. Related devices and methods are also disclosed.

Abstract: A tuning circuit disposed between an antenna and wireless network interface card selectively adjusts transmissions from the antenna to plural frequency bands, each band associated with wireless signals of a wireless network provider. A direct current bias selectively applies to tuning circuit analog components to adjust the frequency band as desired to support communication for a selected wireless provider.

Abstract: A first component (CMP1) is connected to the antenna (ANT) and to an impedance matching circuit (CAI) configurable on command and connected to the antenna, and in the absence of another component (CMP2) connected to the antenna, the impedance matching circuit is placed in a first configuration in which it forms with the first component and the antenna a resonant circuit having a first resonant frequency compatible with a carrier frequency. In the presence of a second component (CMP2) connected to the antenna, the impedance matching circuit is placed in a second configuration in which it forms with the first component, the second component and the antenna a resonant circuit having a second resonant frequency compatible with the carrier frequency.

Abstract: A technique is proposed for reducing leakage electromagnetic field that reduces the electromagnetic leakage from a connection point between a communication coupler and a signal transmission apparatus and that can conduct both communication and transmission of electric power. The signal transmission apparatus includes: a first sheet conductive body portion constituting a lower portion electrode; and a second sheet conductive body portion in a mesh shape which is laminated on the first sheet conductive body portion while a gap area is sandwiched therebetween and which includes an uneven mesh size area on which a sheet impedance is continuously changed.

Abstract: This disclosure provides an antenna apparatus in which stable antenna characteristics are maintained by detecting surrounding conditions that affect the antenna characteristics and appropriately compensating the antenna characteristics. More specifically, when surrounding condition such as a human body (e.g., a palm or fingers) approaches and enters an electric field of a pseudo dipole formed by an antenna element electrode, a stray capacitance is sensed and stable antenna characteristics are maintained by appropriately controlling an antenna matching circuit to compensate for a change in the antenna characteristics due to the approach of the surrounding condition.

Abstract: A programmable antenna assembly includes a configurable antenna structure, a configurable antenna interface, and a control module. The configurable antenna structure includes a plurality of antenna elements that, in response to an antenna configuration signal, are configured elements into at least one antenna. The configurable antenna interface module is coupled to the at least one antenna and, based on an antenna interface control signal, provides at least one of an impedance matching circuit and a bandpass filter. The control module is coupled to generate the antenna configuration signal and the antenna interface control signal in accordance with a first frequency band and a second frequency band such that the at least one antenna facilitates at least one of transmitting and receiving a first RF signal within the first frequency band and facilitates at least one of transmitting and receiving a second RF signal within the second frequency band.

Abstract: A configurable antenna assembly includes an antenna structure and a configurable antenna interface. The antenna structure is operable, in a first mode, to provide a first antenna structure and a second antenna structure, wherein the first antenna structure receives an inbound radio frequency (RF) signal and the second antenna structure transmits an outbound RF signal. The configurable antenna interface is operable in the first mode to provide a first antenna interface and a second antenna interface, wherein the first antenna interface is configured in accordance with a receive adjust signal to adjust at least one of phase and amplitude of the inbound RF signal, and wherein the second antenna interface is configured in accordance with a transmit adjust signal to adjust at least one of phase and amplitude of the outbound RF signal.

Abstract: An implantable medical device can include an implantable antenna for communication with external devices or other internal devices. Changes in the patient's body position, weight, composition or other factors may change the efficiency of the implantable antenna and hinder communication. The disclosed circuit can calculate a value for a matching network for an implantable telemetry circuit to decrease an impedance difference between the implantable telemetry circuit and the implantable antenna or increase or maximize a communication power transfer value associated with the implantable medical device.

Abstract: The present invention relates to a method for producing an antenna operating in a given frequency band, from a dual-band antenna. According to the method, the dual-band antenna is a broadband slot antenna that receives and/or transmits electromagnetic signals at a first frequency and at a second higher frequency. The antenna is powered by a single power supply line, and the free end of the power supply line is connected, by a connection means that can be opened or closed, to at least one means for rejecting one of the frequencies. This invention can be used in producing generic electronic boards.

Abstract: A variable capacitance device includes a fixing member, a fixed electrode having a first end side fixed by the fixing member, an actuator element having a first end side fixed by the fixing member directly or indirectly, a movable electrode provided to connect to the actuator element directly or indirectly and disposed to approximately face the fixed electrode, and a driving section deforming a second end side of the actuator element, to change a distance between the fixed electrode and the movable electrode.

Abstract: Methods and systems for reducing AM/PM and AM/AM distortion are disclosed and may comprise selectively coupling and impedance matching one of a plurality of tunable antennas to a single programmable output stage comprising a single power amplifier in a transmitter. A programmable matching circuit comprising adjustable inductance and capacitance may be used to impedance match the antenna to the output stage. The selected tunable antenna may be coupled to the output stage utilizing a programmable switch array, which may comprise at least one transistor integrated on an integrated circuit including the output stage, for example. The tunable antennas may be designed to operate in different frequency bands and to be tuned within one or more frequency bands. The programmable matching circuit may be integrated on the chip or external to the chip. The matching circuit capacitance may be integrated on-chip, and the inductance may be located off-chip.

Abstract: When first and second housings are in an open state, first and second switches are electrically opened, and thus, a first antenna element and a ground conductor operate as a first dipole antenna, and a second antenna element and the ground conductor operate as a second dipole antenna with isolation from the first dipole antenna by the slit. When the first and second housings are in the closed state, the first and second switches are electrically closed, and thus, the first antenna element operates as a first inverted F antenna on the ground conductor, and the second antenna element operates as a second inverted F antenna on the ground conductor with isolation from the first inverted F antenna by the slit.

Abstract: An antenna module includes an antenna, a tunable matching circuit, a power detector and a control unit. The antenna comprises a feeding point. The tunable matching circuit, electrically connected between the antenna and the power detector and configured to provide a loading impedance, comprises a plurality of tunable impedance elements connected to each other and electrically connected to the feeding point as well. The power detector is electrically connected between the tunable matching circuit and a power amplifier and configured to detect a power indicator. The control unit, electrically connected to the tunable matching circuit and the power detector, is configured to read the power indicator and RSSI to generate a control signal for the tunable matching circuit, which consistently changes the loading impedance to achieve impedance matching.

Abstract: The present invention relates to an antenna matching structure, an antenna matching method and a wireless communication terminal. In which, the antenna matching structure comprising: a measuring unit configured to measure a RSSI value; a control unit configured to generate a first switching control signal when the RSSI value measured by the measuring unit is less than a predetermined threshold; and a parameter switching unit configured to select one set of matching parameters from predetermined at least one set of matching parameters according to the first switching control signal, and switch current matching parameters of the adjustable antenna matching circuit to the selected matching parameters. According to the embodiments of the present invention, a higher RSSI value can be acquired to ensure the signal transmission quality.

Abstract: A programmable antenna includes a fixed antenna element and a programmable antenna element that is tunable in response to at least one antenna control signal, wherein tuning the programmable antenna element changes an impedance of the antenna. A programmable impedance matching network is tunable in response in response to at least one matching network control signal to adjust for the changes in the impedance of the antenna.

Abstract: The invention relates to a system comprising an array of two or more receiving antennas (11, 12, 13) for receiving RF signals, each receiving antenna being connected, via a matching network (19, 20, 21), to a low-noise amplifier (22, 23, 24) presenting an input impedance to the matching network (19, 20, 21), each chain consisting of a receiving antenna (11, 12, 13), a matching network (19, 20, 21) and a low-noise amplifier (22, 23, 24) constituting a part of a receiving channel of the system, the matching networks (19, 20, 21) transforming optimum impedances of the low-noise amplifiers (22, 23, 24), the optimum impedances providing optimum noise performance of the low-noise amplifiers (22, 23, 24), wherein each receiving channel comprises at least one switchable impedance (28, 29, 30) at the input of each low-noise amplifier (22, 23, 24) for switching the input impedance as presented to each matching network (19, 20, 21) to a value being the complex conjugate of the optimum impedance of the respective low-noi

Abstract: A method of matching a receive-only antenna (60) for use in receiving video signals in which measurements made on a transceiver's antenna (14) when in an transmitting mode are used in matching the receive-only antenna. The ratio of the amplitude of the reflected signal to the strength of the transmitted signal strength is used not only in selecting components for matching the transceiver's antenna (14) but also in selecting components for matching the receive-only antenna (60). The ratio may be applied to respective look-up tables (54, 64) for selecting the components to be used in matching the respective antennas.

Abstract: An impedance matching circuit for matching planar antennas includes a signal path with a signal path input and a signal path output. A first capacitive element with variable capacitance is connected between the signal path input and signal path output. A second capacitive element with variable capacitance is connected between the signal path and ground. A first inductive element is connected between the signal path input and ground. A second inductive element is connected between the signal path output and ground. An antenna line with an impedance between 30 and 60 ohm is connected to the signal path output.

Abstract: A loop antenna is provided. The loop antenna includes: a substrate; an outer pattern including at least one loop on a surface of the substrate; and an inner pattern in an inner region of the at least one loop of the outer pattern, an end of the inner pattern being connected to an end of the outer pattern, wherein the inner pattern is configured so that an electric current flows in the inner pattern in a direction opposite to a direction in which the electric current flows in the outer pattern. Accordingly, an H-Field characteristic of the loop antenna can be enhanced, thereby allowing the loop antenna to have a decreased size and an improved performance.

Abstract: A (radio frequency) RF reception system includes an RF receiver that demodulates an RF signal at a sequence of selected carrier frequencies. A frequency hop module, coupled to the RF receiver generates the sequence of selected carrier frequencies. A programmable antenna is tuned to each of the sequence of selected carrier frequencies to receive the RF signal via an antenna current.

Abstract: A technique for tuning an antenna may include one or more of the following: working against a ground plane, utilizing the third dimension by alternating layers on a substrate, integrating an inductive short stub in the substrate to improve port matching, and making a tuning port available for capacitive loading and resonance modification.

Abstract: An antenna system is disclosed that includes two or more antennas and an impedance matching network. The antennas of the antenna system are closely separated, such as by a distance of no more than a wavelength of received signals divided by two. The impedance matching network is adapted to respond to and counteract performance degradation resulting from cross coupling between the antennas. Related methods for use in an antenna system are disclosed.

Abstract: An antenna device that includes an antenna having a single feed and a shunt circuit. The shunt circuit includes a first shunt matching circuit causing impedance, viewed from a main path connecting the antenna and a radio frequency circuit, to be substantially infinite with respect to all frequency ranges handled by the antenna, and a second shunt matching circuit providing a predetermined impedance characteristic with respect to a first subset of the frequency ranges handled by the antenna. Each of the first and second shunt matching circuits are selectively connected to the main path, and a selection controller of the antenna device controls selection of which of the first and second shunt matching circuits are connected to the main path.

Abstract: A spiral, helical antenna is configured to produce a generally circular polarized radiation pattern covering a range of frequencies, over a ground plane. The antenna is comprised of a spring-like spiral conductor that may be held in compression by a size and shape regulating outer nonconductive membrane. The assembly may be compressed and or extended to adjust the antenna for best performance in a particular situation. The assembly may be compressed into a generally flattened state for storage and or transportation, and extended at a later time for use. Accurate antenna dimensions and good performance are afforded by the use of high quality spring materials in conjunction with precise membrane dimensions.

Abstract: A non-contact communication device is disclosed comprising: an antenna having an input impedance and being for receiving an AC signal having a voltage and a current, a main unit comprising a power-extraction unit and a communication unit and having a main unit impedance, a tuning circuit, and a matching network for matching the input impedance to the main unit impedance, characterised in that the tuning circuit comprises a phase detector for detecting a phase difference between the voltage and the current and is configured to adjust the impedance of the matching network in dependence on the phase difference. Also disclosed is a method for tuning a non-contact communication device.

Abstract: A method for adjustment of a radio-frequency circuit by impedance loading features includes designing a plurality of test fixtures each corresponding to an impedance loading area according to a predefined operating frequency band, coupling each of the plurality of test fixtures to a test point of the radio-frequency circuit for measuring a plurality of radio-frequency characteristic sets, determining an optimal impedance loading area of the radio-frequency circuit according to the plurality of radio-frequency characteristic sets, and adjusting the radio-frequency circuit according to the optimal impedance loading area.