548 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.

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.

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.

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.

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.

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.

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.

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.