554 results about "Antenna matching" patented technology

The present invention provides a device and method for antenna matching applied in a transceiver. Wherein, the transceiver has a transmission module and a receiving module. The antenna matching device includes a matching circuit, a duplexer, a circulator, a control unit, and a coupler. Wherein, the matching circuit adjusts the matching impedance according to an adjusting signal and generates a reflection signal. The duplexer receives the reflection signal and a receiving signal and respectively sent the received two signals to the control unit and the receiving module according to their frequencies. The control unit, according to the reflection signal, estimates the adjusting signal for adjusting the matching circuit to an optimal state of the load impedance of the matching antenna, such that the antenna gain may is maximized, and a best efficiency is obtained no matter during receiving or transmission.

A dual-band antenna matching system and a method for dual-band impedance matching are provided. The method comprises: accepting a frequency-dependent impedance from an antenna; and, selectively supplying a conjugate impedance match for the antenna at either a first and a second communication band, or a third and a fourth communication band. More specifically, the method comprises: tuning a first tuning circuit to a first frequency; and, simultaneously tuning a second tuning circuit to a second frequency. In response, a conjugate match is supplied to the antenna in the first communication band in response to the first frequency. Simultaneously, the antenna is matched in the second communication band in response to the second frequency. When the first tuning circuit is tuned to a third frequency, and the second tuning circuit is tuned to a fourth frequency, then conjugate matches are supplied for the third and fourth communication bands, responsive to the third and fourth frequencies, respectively.

The present invention features an RFID smart shelf reader capable of working with a wide range of antenna types and numbers. The smart shelf reader readily accommodates and accurately reads a diverse range of package shapes, sizes, and contents. Multiple tags in close proximity to one another are accurately read by the smart shelf reader. The reader includes features for optimizing its own interface by periodically recalibrating itself to the current antenna load characteristics caused by varying external conditions, primarily in the type, number, and position of merchandise items on the shelf proximate at least one of the antennas. An external I / O interface is provided for communication with a remote controller.

A method and system performs antenna tuning using detected changes in antenna self-capacitance in a wireless communication device. A modem detects changes in antenna self-capacitance by utilizing multiple antenna elements. The modem determines a current antenna loading condition using the detected changes in antenna self-capacitance. The modem determines appropriate tuning states for each antenna matching and tuning circuit (AMTC) associated with a respective antenna element. In order to determine the appropriate tuning states, the modem utilizes pre-established antenna self-capacitance information which is mapped to antenna tuning states. The antenna tuning states which are respectively mapped to pre-established antenna self-capacitance are empirically pre-determined by correlating antenna self-capacitance changes to antenna impedance changes. The modem is thus able to change the tuning states of multiple tunable matching circuits and perform antenna tuning using (a) detected real-time changes in antenna self-capacitance and (b) pre-established mappings of antenna self-capacitance and antenna tuning states.

This invention constructs an antenna matching circuit able to avoid a bad influence when a conductor, such as a metal, or tag, approaches a reader / writer, and dissolves a communication defect area on the reader / writer and stably maintains a communication distance. In this invention, in a RFID system, when the tag corresponds to the generating area of a magnetic field of the reader / writer, a radio wave for sending information to the reader / writer is outputted by operating a control circuit of the tag by electric power generated in an antenna coil of this corresponding tag. A conductor is arranged near the antenna coil of the reader / writer and an eddy current is intentionally flowed. Thus, the communication defect between the reader / writer and the tag approaching this reader / writer is reduced.

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.

The invention discloses a monopole radio frequency antenna comprising a metal sheet, a feeder line and a medium for the placement of the metal sheet and the feeder line. The feeder line is fed into the metal sheet through a coupling mode. The monopole radio frequency antenna has the advantages of small size, simple machining, low cost, high utilization rate of an antenna radiation area, easy matching design of a multimode antenna, high interference resisting capability and the like.

The present disclosure relates to combining tunable antenna matching circuit adjustments and RF power amplifier output power adjustments of a first RF terminal in response to output power adjustment commands received from a second RF terminal. The output power adjustment commands may be part of an output power control loop between the first RF terminal and the second RF terminal to control the output power from the first RF terminal. The first RF terminal may include an RF receiver, an RF power amplifier, and a tunable antenna matching circuit coupled between an output of the RF power amplifier and an antenna. The tunable antenna matching circuit adjustments may be impedance adjustments of the tunable antenna matching circuit and the RF power amplifier output power adjustments may result from adjustments to one or more input signals to the RF power amplifier.

An apparatus and a method of realizing an antenna matching in accordance with a user's body effect and a state of a mobile device are provided. The method includes determining a state of the mobile device on a basis of a call mode and at least one of whether an external device is connected to the mobile device, whether a receiver is being used, whether a speaker is being used, and whether a proximity sensor is activated, determining an optimal Tunable Matching Network (TMN) circuit adjustment value in accordance with the determined state, and performing the antenna matching in accordance with the optimal TMN circuit adjustment value.

A method and communications device for providing antenna tuning to compensate for antenna de-tuning caused by a presence of an object detected using an antenna element within a capacitive touch and proximity sensor (CTPS). The CTPS propagates object detection signals associated with a detected object to a detection IC. An object detection and antenna tuning (ODAT) logic uses object detection signal information to generate tuning control signals to trigger compensatory antenna tuning, based on pre-established mappings of object detection signal data and antenna tuning states. The tuning control signals indicate at least one of (a) a level of compensatory antenna impedance tuning and (b) an amount of compensatory antenna length adjustment. In response to generating the tuning control signals, the ODAT logic triggers the propagation of the tuning control signals to the antenna matching and control circuit to provide the corresponding antenna tuning.

Real-time calibration of a tunable matching network that matches the dynamic impedance of an antenna in a radio frequency transmitter system. The radio frequency transmitter system includes two non-linear equations that may be solved to determine the reflection coefficient of the antenna. The tunable matching network is repeatedly perturbed and the power reflected by the antenna is measured after each perturbation at the same node within the tunable matching network. The power values are used by an optimizer in converging to a solution that provides input impedance of the antenna. The elements of the matching circuit are adjusted to match the input impedance of the antenna.

An internal multiband antenna intended to be used in small-sized radio devices and a radio device having an antenna according to the invention. The radiating element (330) of the antenna is a conductive part in the cover of the radio device or a conductive surface attached to the cover. The radiating element is fed electro-magnetically by a feed element (320) connected to the antenna port. The feed element is designed (321, 322) such that it has, together with the radiating element and ground plane (310), resonating frequencies in the areas of at least two desired operating bands. In addition, the resonating frequency of the radiating element itself is arranged to fall into an operating band. Antenna matching is provided by feed element design and short-circuiting (315). The radiating element design can be based on the desired external appearance of the device, and the locations of the operating bands and antenna matching are provided through feed element design and short-circuiting. The antenna requires a relatively minor space within the device.

The antenna matching circuit control device with an antenna body includes a sensing module, a processing module, a power adjusting module and a frequency adjusting module. The sensing module senses an object that approaches the antenna body and outputs a sensing signal accordingly. The processing module is coupled to the sensing module and outputs a first control signal and a second control signal according to the sensing signal. The power adjusting module is coupled to the processing module and controls a power amplifier to couple with one of a plurality of first matching circuits according to the first control signal. The frequency adjusting module is coupled to the antenna body and the power adjusting module. The frequency adjusting module controls one of a plurality of second matching circuits to couple with one of the first matching circuits according to the second control signal.

An antenna intended to be used in a small-sized and flat radio device, and to a radio device which has an antenna according to the invention. The base element of the antenna is a monopole-type conductor (110) internal to the device. This conductor may be designed such that the harmonic nearest to the fundamental resonating frequency can be utilized in providing an upper operating band. In addition to the base element the antenna structure comprises a parasitic element (120) which functions as both an auxiliary radiator and antenna matching element. Matching is optimized using an inductive component (125) which connects the parasitic element to signal ground. The antenna gain achieved is considerably higher than that of known antenna structures occupying the same space (h), and the antenna matching is improved, compared to known internal monopole antennas.

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

A distributed multiband antenna intended for radio devices, and methods for designing manufacturing the same. In one embodiment, a planar inverted-F antenna (PIFA) configured to operate in a high-frequency band, and a matched monopole configured to operate in a low-frequency band, are used within a handheld mobile device (e.g., cellular telephone). The two antennas are placed on substantially opposing regions of the portable device. The use of a separate low-frequency antenna element facilitates frequency-specific antenna matching, and therefore improves the overall performance of the multiband antenna. The use of high-band PIFA reduces antenna volume, and enables a smaller device housing structure while also reducing signal losses in the high frequency band. These attributes also advantageously facilitate compliance with specific absorption rate (SAR) tests; e.g., in the immediate proximity of hand and head “phantoms” as mandated under CTIA regulations. Matching of the low-frequency band monopole antenna is further described.

A novel and useful apparatus for and method of improving antenna matching and reducing mismatch loss for a VHF receiver such as an FM receiver. The invention can be used in a very low cost implementation of a single chip radio such as used in cellphone applications. The impedance of the low cost VHF antenna in cellphone application can dramatically vary across time, frequency and depending on the human body proximity resulting in a large mismatch loss. The adaptive antenna matching mechanism uses dynamically configurable on-chip variable capacitors to provide a custom matching network with the external inductor in a pi-network configuration. The variable ranges of the on-chip capacitors enable adaptation in a closed loop manner so that the optimum SNR is achieved thus ensuring minimum mismatch loss. The mechanism measures RSSI and SNR and, using a novel adaptive calibration mechanism, adjusts the internal matching network capacitors such that the mismatch loss is minimized.

A radio frequency (RF) communication device is provided comprising means for switching between a low current operating mode and a high current operating mode. The low current operating mode is optimized to conserve power while the RF device is awaiting a wake-up signal from an interrogator. The high current operating mode is optimized to provide antenna matching during backscatter communications so as to maximize the range of backscatter communication between the RF device and the interrogator. Further provided, is a system and method for optimizing power consumption and backscatter range within an RF communication device.

Disclosed is an antenna matching device of a folder type portable wireless terminal with a built-in antenna. In the antenna matching device, a π-type matching circuit is connected between an built-in antenna and a duplexer, one end of a passive element is shunted between the π-type matching circuit and the duplexer, and an active element opens or connects the other end of the passive element to ground according to the opening or closing of a folder of the terminal. The antenna matching device lowers antenna impedance difference between the opened and closed states of the folder, such that the terminal can constantly maintain its radiation performance, such as VSWR and resonant frequency, regardless of the opened or closed position of the folder.

The invention provides an antenna system and a mobile terminal, and relates to the technical field of antennas. The antenna system is applied to a mobile terminal, and includes: a first metal arm and a second metal arranged on two end parts of a frame of one side edge of the mobile terminal; and a third metal arm arranged on the frame of the side edge and located between the first metal arm and the second metal arm. A first opening is arranged between the third metal arm and the first metal arm, and a second opening is arranged between the third metal arm and the second metal arm; a first end of the third metal arm is connected to the ground through a radio frequency front end matching circuit; and a second end of the third metal arm is connected to the ground through a first antenna matching circuit. The scheme of the invention solves the problem of poor antenna signal quality when mobile terminals at present use metal structures, realizes antenna signals of higher quality, and tuning is easy.

A front end module for a wireless transmission / reception device has two antennas and two signal paths connected thereto. A mismatch in the antenna is identified by monitoring the transmitted power and the reflected power in the active and passive signal paths and using the powers in a controller to generate a control signal for the antenna tuner. In this case, decreasing isolation between the first and second antennas and the first and second signal paths is identified, and is compensated for using different devices, in order to ensure faster and safer antenna matching.

An antenna matching apparatus capable of eliminating impedance mismatching produced when the antenna element is placed close to the human body in a short time and reducing power loss due to impedance mismatching. This apparatus connects variable capacitance capacitors VC1 and VC2 for impedance adjustment to transmission antenna element TA1, connects variable capacitance capacitors VC3 and VC4 to reception antenna element RA1 respectively, provides beforehand capacitance values of respective variable capacitance capacitors which are impedance matched in a table in a one-to-one correspondence with the distances between the antenna elements and human body and stores the table in storage section (106). The apparatus completes adaptive control processing for any one of transmission antenna element TA1 and reception antenna element RA1, reads other capacitance values corresponding to the capacitance value at that moment from the table and performs adaptive control processing on other antenna elements using the read values as initial values.

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.

This disclosure relates to real-time calibration of a tunable matching network that matches the dynamic impedance of an antenna in a radio frequency receiver system. The radio frequency receiver system includes two non-linear equations that may be solved to determine the reflection coefficient of the antenna. Control system that calculates, in realtime, a value of an input impedance of the antenna to match a load in a receiver system, wherein said impedance is calculated directly using a closed-form solution. The reflection coefficient of the antenna may be used to determine the input impedance of the antenna. The elements of the matching circuit are then adjusted to match the input impedance of the antenna.

The invention provides an NFC (Near Field Communication) antenna and a mobile phone using the same, wherein the antenna comprises two NFC antenna coils which are spliced at the same plane through two parallel double-conductor lines; and a feed end connected with an antenna matching circuit is led out from the middle points of the parallel double-conductor lines respectively. The mobile phone comprises a mobile phone PCB (Printed Circuit Board) main board, an NFC chip, an antenna matching circuit and an NFC antenna. According to the NFC antenna and the mobile phone provided by the invention, two NFC antenna coils are set, two NFC antenna coils are spliced at the same plane by using two parallel double-conductor lines, and the feed end connected with the antenna matching circuit is led out from the middle points of the parallel double-conductor lines respectively, thus adding and number of windings of the antenna coils, the magnetic induction intensity can be strengthened by the antenna without increasing ferrite materials or turns of the antenna coil, and the thickness and manufacturing cost of the mobile phone are reduced effectively.

Real-time calibration of a tunable matching network that matches the dynamic impedance of an antenna in a radio frequency receiver system. The radio frequency receiver system includes two non-linear equations that may be solved to determine the reflection coefficient of the antenna. The tunable matching network is repeatedly perturbed and the power received by the antenna is measured after each perturbation at the same node in the matching network. The measured power values are used by an optimizer in converging to a solution that provides the reflection coefficient of the antenna. The reflection coefficient of the antenna may be used to determine the input impedance of the antenna. The elements of the matching circuit are then adjusted to match the input impedance of the antenna.

An antenna includes antenna elements, an electric power feeding portion for supplying an electric power to each of the antenna elements, a short-circuit element for antenna matching electrically connected to the electric power feeding portion, and a ground connected to the short-circuit element. The antenna is built in a chassis made of a metal, and the chassis made of a metal and the ground are electrically connected to each other.

The invention provides a method for selecting a full-duplex antenna in a multiple-in multiple-out (MIMO) system. The method comprises the following steps of: 1, performing self-interference elimination on receiving antennae at two communication ports in a full-duplex antenna system to acquire corresponding self-interference channels; 2, performing equalization processing on signals received by the receiving antennae at the two communication ports to acquire postprocessing signals of corresponding transmitting antennae; 3, when distribution of the self-interference channels corresponding to the receiving antennae at the two communication ports accords with independent identically distributed Rice distribution, calculating the postprocessing signal to interference and noise ratio of the receiving antennae at the two communication ports; and 4, traversing all antenna pairs between the two communication ports based on antenna selection criteria to determine a final antenna matching scheme. The advantages of a full-duplex antenna technology and an MIMO technology are combined, a scheme with gain is selected from all possible antenna matching schemes, channel capacity is improved, and the whole performance of the system is improved.