56results about "Loop antennas with variable reactance" patented technology

Embodiments of this application relate to the field of antennas, and provide a terminal antenna. The terminal antenna includes n radiators. The n radiators include a first radiator, a second radiator, and a third radiator. Lengths of the first radiator, the second radiator, and the third radiator form a descending arithmetic progression. The first radiator, the second radiator, and the third radiator are arranged in sequence to form two gaps. A coupling capacitance formed by the first radiator and the second radiator through the corresponding gap is greater than a coupling capacitance formed by the second radiator and the third radiator through the corresponding gap. The first radiator, the second radiator, and the third radiator are any three of the n radiators distributed in sequence.

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 radio frequency (RF) circuit 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 of the transmission line, an impedance transformation circuit, and an impedance matching detuning circuit electrically connected between the transmission line and the impedance transformation circuit, the impedance matching detuning circuit comprising a plurality of reactive impedance elements and two or more switches operable to controllably switch between configurations of the plurality of reactive impedance elements to effect matching of an overall impedance of the RF circuit to a predetermined input impedance seen by the amplifier circuit at a predetermined RF frequency during a receive mode of the MRI scanner, while effecting an increase in impedance at the antenna to reduce the sensitivity of the antenna to RF signals at a predetermined frequency during an excitation mode of the MRI scanner.

Provided are a circularly polarized antenna and an intelligent terminal. The circularly polarized antenna includes an annular radiator and a first feed terminal. A first breakpoint is provided on the radiator, and a first capacitor or a first inductor is connected in series with the radiator at the first breakpoint. One end of the first feed terminal is electrically connected to the radiator, and another end of the first feed terminal is electrically connected to a first feed module of a mainboard. When a capacitor or inductor is connected in series with the radiator at the first breakpoint, the resonance frequencies of a first mode and a second mode excited on the radiator which are mutually perpendicular will both change, so that the difference between the resonance phase of the first mode and the resonance phase of the second mode reaches 90°, thereby the circular polarization is realized.

A terminal antenna and an electronic device, which relate to the field of antenna technologies. By adding a choke structure, optimization of a maximum gain of an original antenna is implemented, and in addition. A specific solution is as follows: the terminal antenna includes a first radiator and a second radiator. a first end of the first radiator is provided with a feed, and a second end of the first radiator is connected to a reference ground; the first radiator is provided with a gap that runs through the first radiator, the gap is in an interdigitated structure, and there are at least two gaps; and the second radiator is arranged on a side of the first radiator, the second radiator is L-shaped, the second radiator and the reference ground enclose an inverted L-shaped first gap.

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.

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.

The invention relates to a liquid metal microfiber system with a balanced transmission line that comprises at least one liquid metal microfiber twin line section. The liquid metal microfiber twin line section comprises a plastic core material defining two separately formed portions that each comprise a liquid metal such that two separate liquid metal conductors are confined by the plastic core material. Further, a method of controlling a flexible liquid metal microfiber system is described.

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 fluid sensing system including a planar antenna, the antenna having a non-fluid-absorbing substrate, the non-fluid-absorbing substrate including a seat configured to embed a fluid-absorbing element; and a conductor layer on the non-fluid-absorbing substrate. The planar antenna has a resonant frequency, and is configured to vary the resonant frequency based on fluid absorbed by the fluid-absorbing element. A method for determining fluid properties, the method by providing the fluid sensing system; embedding a fluid-absorbing element in the seat of the non-fluid-absorbing substrate; and determining fluid properties or fluid dielectric properties, of a fluid absorbed by the fluid-absorbing element based at least on a frequency of maximum signal reception power, the signal reception power being at least a part of the signal power of the transmitted signal, received by a reception antenna.

A device includes a plurality of antennas, including one or more active antennas, the antennas being configured in one of a plurality of possible configurations to achieve operation in WAN, LTE, WiFi, or WiMax bands, or a combination thereof. In some embodiments, a passive antenna is utilized with lumped loading to fix the antenna tuning state. A primary and auxiliary radiator can be included in the device and configured for WAN / LTE bands, while additional antennas can be incorporated for WiFi and WiMax bands. Various antenna configurations incorporate the antenna having multiple coupled regions.

The antenna architectures disclosed herein may include a magnetic dipole antenna that includes a radiating element formed in an open loop that includes at least first and second portions that are positioned opposite each other. The magnetic dipole antenna may further include an electrically conductive via connecting the first and second opposing portions of the radiating element. The magnetic dipole antenna may further include an antenna feed disposed within the electrically conductive via. The first portion of the radiating element may be shorter in length than the second, opposite portion of the radiating element, and the difference in length between the first and second portions of the radiating element may form a capacitive gap across the radiating element. Various other systems, apparatuses, wearable electronic devices, and methods of manufacturing are also disclosed.

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.

Systems and methods for operating a radio system include configuring a first antenna of a plurality of antennas in a wireless device to operate in a configured mode of a plurality of modes, wherein the plurality of modes include a first mode of operating as a quarter wave for operation in a 2.4 GHz band, a second mode of operating as a half wave for operation in a 5 GHz band, and a third mode of operating simultaneous as a half wave and a quarter wave for operation in both the 2.4 GHz band and the 5 GHz band; and operating a first radio of a plurality of radios connected to the first antenna in the configured mode of the first antenna.

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 provide a terminal antenna and an electronic device, which relate to the field of antenna technologies. By adding a choke structure, optimization of a maximum gain of an original antenna is implemented, and in addition, an overall radiation performance of the antenna is improved. A specific solution is as follows: the terminal antenna includes a first radiator and a second radiator, a first end of the first radiator is provided with a feed, and a second end of the first radiator is connected to a reference ground; the first radiator is provided with a gap that runs through the first radiator, the gap is in an interdigitated structure, and there are at least two gaps; and the second radiator is arranged on a side of the first radiator, the second radiator is L-shaped, the second radiator and the reference ground enclose an inverted L-shaped first gap, and a non-open end of the first gap is close to the first radiator.

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.

An antenna device is disclosed. The antenna device includes a main antenna element and a sub antenna element, the sub antenna element being configured to form a mutual coupling with the main antenna element where a central axis of the sub antenna element forms an angle different from a right angle with a central axis of the main antenna element.

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.

An example discloses a near-field wireless device comprising: a stack of layers distributed along a first axis; a first near-field antenna having a conductive surface and embedded in a first layer within the layer stack; wherein the conductive surface is configured to carry a non-propagating quasi-static near-field electrical induction signal for on-body near-field communication; a second near-field antenna having an induction loop and embedded in a second layer within the layer stack; wherein the induction loop is configured to carry a non-propagating quasi-static near-field magnetic induction signal for off-body near-field communication; wherein the first layer and the second layer are different layers; and wherein the first antenna and the second antenna have no galvanic contact.

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.

An antenna architecture disclosed herein may include a magnetic dipole antenna including a radiating element formed as a split ring including at least a first portion and a second portion positioned opposite each other. The magnetic dipole antenna may also include a conductive via connecting the first portion and an opposing second portion of the radiating element. The magnetic dipole antenna may also include an antenna feed disposed within the conductive via. A first portion of the radiating element may be shorter in length than an opposing second portion of the radiating element, and a difference in length between the first and second portions of the radiating element may form a capacitive gap across the radiating element. Various other systems, apparatuses, wearable electronic devices, and methods of manufacture are also disclosed.