22results about "Loop antennas with variable reactance" patented technology

An electronic device according to one embodiment of the present invention comprises: a housing including a first plate and a second plate; a side member; a display; a printed circuit board; an NFC circuit; and a processor. The side member comprises: a first metal frame; a second metal frame; a first insulation member disposed between the first metal frame and the second metal frame; and a support member which forms a first loop with the first metal frame and a second loop with the second metal frame, and supports the display and the printed circuit board. The NFC circuit is electrically connected to the first loop, and the second loop can be electrically connected to a first reactive load circuit.

A controllable electrical outlet may comprise a resonant loop antenna. The resonant loop antenna may comprise a feed loop electrically coupled to a radio-frequency (RF) communication circuit and a main loop magnetically coupled to the feed loop. The controllable electrical outlet may comprise one or more electrical receptacles configured to receive a plug of a plug-in electrical load and may be configured to control power delivered to the plug-in electrical load in response to an RF signal received via the RF communication circuit. The RF performance of the controllable electrical outlet may be substantially immune to devices plugged into the receptacles (e.g., plugs, power supplies, etc.) due to the operation of the resonant loop antenna. For example, degradation of the RF performance of the controllable electrical outlet may be less when the controllable electrical outlet includes the resonant loop antenna rather than other types of antennas.

One example discloses a near field wireless device comprising: a near field antenna; a variable current source; a controller coupled to the near field antenna and the variable current source; wherein the controller is configured to measure a transmission quality factor (Qtx) of the near field antenna; and wherein the controller is configured to increase a current sent by the variable current source to the near field antenna when the measured Qtx is below a minimum Qtx.

An electronic device according to one embodiment of the present invention comprises: a housing including a first plate and a second plate; a side member; a display; a printed circuit board; an NFC circuit; and a processor. The side member comprises: a first metal frame; a second metal frame; a first insulation member disposed between the first metal frame and the second metal frame; and a support member which forms a first loop with the first metal frame and a second loop with the second metal frame, and supports the display and the printed circuit board. The NFC circuit is electrically connected to the first loop, and the second loop can be electrically connected to a first reactive load circuit.

A capacitively or inductively driven spiral antenna creates an electric current distribution of a dipole, which generates a sensible magnetic field for various military applications including detecting and pre-detonating improvised explosive devices (IEDs). The antenna includes a dielectric substrate, a spiral antenna, driving elements such as tuning forks or loop, and a coaxial cable that connects to a source terminal. The substrate is a low dielectric loss insulating material to provide support for the antenna. The spiral antenna is tuned to a natural frequency is disposed on the substrate. The coaxial cable extends from the substrate to the source terminal.

In some embodiments, a radio frequency identification (RFID) system may include at least one Ultra High Frequency (UHF) antenna component, a conductive loop having a largest dimension that is smaller than the wavelength of radiation transmitted at a Microwave Frequency (MW). The conductive loop may define a gap and an RFID chip may be electrically coupled to the conductive loop. The conductive loop may be configured to be resonant at an Ultra High Frequency (UHF) and less resonant at Microwave Frequency (MW). The antenna component may be selected from the group consisting of a dipole antenna, a monopole antenna, a loop antenna, or a slot antenna.

Provided is a resonant multi-loop antenna circuit for magnetic field communication. The resonant multi-loop antenna circuit includes a first loop antenna and a second loop antenna arranged substantially on a same plane, and a first / a second matching circuit connected in series to the first and the second loop antenna respectively. The first matching circuit may be configured to minimize reactance of the first loop antenna and the first matching circuit connected in series to each other at a first carrier frequency, the second matching circuit may be configured to minimize the reactance of the second loop antenna and the second matching circuit connected in series to each other at a second carrier frequency, and the first loop antenna and the second loop antenna may be arranged so that a center of the first loop antenna is spaced apart from a center of the second loop antenna by a predetermined distance.

In some embodiments, a wireless communication device is disclosed. In some embodiments, the present subject matter provides the wireless communication device including a communication circuit and an antenna structure. In some embodiments, the antenna structure is formed out of an electrically conductive material. In some embodiments, an impedance-matching structure is formed out of the electrically conductive material. In some embodiments, the impedance-matching structure includes one or more microstrip lines adapted to be electrically shunted to match an impedance of the communication circuit. In some embodiments, the impedance-matching structure may be electrically coupled to the antenna structure. In other embodiments the impedance-matching structure may be electro- magnetically coupled to the antenna structure. In some embodiments, the one or more microstrip lines are electrically shunted by soldering at least one microstrip line. In some embodiments, the present subject matter also provides a method for impedance-matching of a wireless communication device.

A wrist-worn electronic device comprises a housing, a first antenna, a second antenna, and an electrical switch. The housing includes a circumferential side wall, an electrically conductive bezel, a bezel retainer, a lower ring and an electrically conductive bottom plate. The first antenna is formed in part by a portion of the bezel and receives a first wireless signal having a first frequency in a global navigation satellite system (GNSS) band. The second antenna is formed in part by at least a portion of the bottom plate and transmits a second wireless signal to a non-terrestrial network (NTN), receives a third wireless signal from the NTN, or both. The electrical switch having a plurality of selectable positions each associated with a tuning network that causes the second antenna to transmit the second wireless signal at a second frequency and to receive the third wireless signal at a third frequency.

Embodiments of this application disclose a terminal monopole antenna based on coupled feeding, relate to the technical field of antennas. The antenna includes a feed stub and a radiation stub. The radiation stub includes at least one radiator. Ends on two sides of the radiator are coupled to a reference ground through a first capacitor and a second capacitor. The feed stub is not connected to the radiation stub. The feed stub is arranged between the radiation stub and the reference ground. A feed point is provided on the feed stub. The feed stub is used to perform coupled feeding on the radiation stub.

An electronic device may comprise: a housing including a first plate and a second plate; a side member comprising a frame; a display; a printed circuit board; an NFC circuit; and at least one processor comprising processing circuitry. The side member comprises: a first metal frame; a second metal frame; a first insulation member comprising a non-conductive material disposed between the first metal frame and the second metal frame; and a support which forms a first loop with the first metal frame and a second loop with the second metal frame, and supports the display and the printed circuit board. The NFC circuit is electrically connected to the first loop, and the second loop can be electrically connected to a first reactive load circuit.

The application discloses a parameter acquisition method of a circular ring antenna array with equal-amplitude and in-phase patch feed, the antenna array comprises a metal ground plane and a plurality of equal-amplitude and in-phase excited antenna units arranged in a linear array on the metal ground plane, the antenna unit has a common mode port, each common mode port comprises two single ports, an active common mode reflection coefficient of the common mode port of the antenna unit is equal to half of the sum of common mode reflection coefficients of the two single ports, the common mode reflection coefficient of the single port is calculated first, and the active common mode reflection coefficient of the common mode port is indirectly obtained; the application has the advantages that the calculation process is simplified, the calculation amount is small, the time consumption is relatively short, and the application is beneficial to popularization and application in engineering practice.

Provided are a circularly polarized antenna structure and a wearable device. The antenna structure being circularly polarized and including a mainboard; an annular radiator, wherein the mainboard and the annular radiator are spaced apart to form an annular gap structure; a feeding terminal electrically connected to the annular radiator at a first end and connected to a feeding module of the mainboard at a second end; and a grounding terminal electrically connected to the annular radiator at a first end and electrically connected to a grounding module of the mainboard through a first capacitor at a second end.

Tunable electromagnetic filters and antennas are described. The tunable electromagnetic filters and tunable antennas comprise a transmission line or antenna feed line, an isolated conductor or semiconductor material, and a support structure supporting a mechanical or electromagnetic actuator. The mechanical or electromagnetic actuator moves the isolated conductor or semiconductor material, and tunes the resonance frequency of an electromagnetic resonator.

An antenna structure includes a middle frame body. The middle frame body includes a main board and an embedded metal, the embedded metal includes a metal body part and a metal extension part, the metal main body part and the metal extension part are an integral structure, the main board includes a first main board and a second main board, the first main board is electrically connected to the metal extension part, the first main board is configured to introduce a radio frequency signal into the metal extension part, the second main board is electrically connected to the metal extension part, and the second main board is configured to ground the metal extension part.

A nonlinear antenna is disclosed which includes a driven element configured to receive a signal of frequency fi incident to the driven element, and a switch electrically connected to the driven element and configured to increase an electrical size of the driven element by interrupting a current flow in the driven element by switching on and off at a switching frequency fsw that is higher than the incident frequency fi.

Playback devices can include touch sensor assemblies with one or more integrated antennas. Such touch sensor assemblies can be incorporated into a playback device such as a headphone device. The playback device can include an electrode comprising a first conductor, a second conductor, and a filter coupled between the first and second conductors, a capacitive-touch circuit coupled to the electrode, and a wireless radio coupled to the second conductor. The capacitive-touch circuit is configured to deliver a capacitive sensing signal to the electrode. The wireless radio is configured to facilitate communication over at least one wireless network via the second conductor.

A radio frequency (RF) circuit is provided for use with a magnetic resonance imaging (MRI) scanner to transmit an RF receive signal to an amplifier circuit, the RF circuit comprising: a transmission line; an antenna electrically connected to a first end portion of the transmission line; an impedance transformation circuit; an impedance matching and detuning circuit electrically connected between the transmission line and the impedance transformation circuit, wherein the impedance matching and detuning circuit includes: multiple reactive impedance elements; and two or more switches operable to controllably switch between configuring the multiple reactive impedance elements to cause matching of overall impedance of the RF circuit to a prescribed input impedance seen at the amplifier circuit at a prescribed RF frequency during a receive mode of the MRI scanner, and to cause an increase of impedance at the antenna, to reduce sensitivity of the antenna to RF signals at the prescribed frequency during an excitation mode of the MRI scanner.

A method of providing a single structure multiple mode antenna is described. The antenna is preferably constructed having a first inductor coil that is electrically connected in series with a second inductor coil. The antenna is constructed having a plurality of electrical connections positioned along the first and second inductor coils. A plurality of terminals is connected to the electrical connections that facilitate numerous electrical connections and enables the antenna to be selectively tuned to various frequencies and frequency bands.

A reconfigurable antenna, a control method therefor, a router, and a signal transceiving device are disclosed. The reconfigurable antenna may include: a horizontal polarization antenna including a patch structure arranged on an upper surface of a first dielectric plate and a first reflector arranged on a lower surface of the first dielectric plate; a vertical polarization antenna arranged below the horizontal polarization antenna and including a third dielectric plate and a fourth dielectric plate which are perpendicular to the first dielectric plate; and an antenna board, including a fifth dielectric plate.

Embodiments of this application provide a printed antenna, to expand an operating frequency and a directivity pattern coverage mode that can be selected by the antenna. The printed antenna is printed on a substrate, a feed module is further disposed on the substrate, and the printed antenna includes a loop antenna body, a feed port, and a switch component. The loop antenna body includes a first end and a second end, there is a spacing between the first end and the second end, a connection line between the first end and the second end forms a closed loop with the loop antenna body, the first end is connected to the feed module by using the feed port, and the second end is connected to a ground point (GND). The feed module is configured to output a feed signal to the loop antenna body by using the feed port. The loop antenna body includes a plurality of loop antenna branches, the switch component is disposed between every two adjacent loop antenna branches, and the switch component is configured to connect or disconnect the two adjacent loop antenna branches.