107results about How to "Reduce SAR value" patented technology

A mobile phone capable of reducing an electromagnetic SAR in human bodies includes a base and a cover disposed on the base. The base includes an antenna for transmitting and receiving electromagnetic waves. The cover includes a screen and buttons. Electromagnetic absorbing materials having electric or magnetic loss are applied on the cover to mitigate electromagnetic waves radiating from the antenna into the user. Moreover, a meandered planar inverted-F antenna is attached to the back of the circuit board near the bottom of the base, which can generate a lower near field at the user's side than those in other directions, thereby reducing the electromagnetic specific absorption rate of the mobile phone in human bodies.

The invention discloses a mobile phone and a method for automatically adjusting the radiation of the mobile phone. The mobile phone includes a radio frequency chip, a baseband chip, a proximity sensor and a power amplifier. The radio frequency chip generates radio frequency signals. The baseband chip is connected with the radio frequency chip and controls the radio frequency chip to generate radio frequency signals. The proximity sensor is connected to the baseband chip and starts when it detects the approach of a human face. The power amplifier is connected with the radio frequency chip and the baseband chip. When the proximity sensor is not activated, the baseband chip controls the power amplifier to adjust the transmission power of the radio frequency signal to the first transmission power according to the first radio frequency parameter. When the proximity sensor is activated, the baseband chip controls the power amplifier according to the second radio frequency parameter. Adjust the transmit power of the radio frequency signal to the second transmit power. The first transmit power is greater than the second transmit power. Through the above method, when the user approaches the mobile phone to talk, the transmission power of the radio frequency signal adjusted by the power amplifier can be automatically reduced, thereby reducing radiation.

The invention discloses a narrow-spacing low-SAR high-isolation MIMO antenna. The narrow-spacing low-SAR high-isolation MIMO antenna comprises a PCB and two antenna bodies used for supporting different service signals, wherein the two antenna bodies are distributed on the two sides of the top end of the PCB and respectively provided with feeding points, the antenna bodies are connected to the PCB through the feeding points respectively, and the feeding points of the two antenna bodies are asymmetrically distributed. According to the antenna, the feeding positions are arranged in the asymmetrical positions on the same side of the PCB, it is avoided that the feeding positions of the antenna are located in the symmetrical current resonance positions, and the isolation degree between the antennas is improved.

A system and method for medium access control (MAC) protocol which controls transmissions in wireless devices to at least substantially comply with specific absorption rate (SAR) limits. The system and method of MAC protocol uses “source-based” time averaging measurements of transmitter “on-times” and an integral of transmission power to direct transmitter duty-cycle such that SAR limits are met. The system and method monitors and controls topology-dependent functions of a node transceiver, including transceiver duty cycle, transceiver transmit power levels and transceiver power-time products, using a automatic transmission control protocol (ATP) to vary functions to maintain specific absorption rate (SAR) limits for handheld and portable devices which are used close to human bodies. In cases in which SAR limits are approached, the ATP can direct the transceiver at the device to adjust each function, or combination of functions, to maintain an acceptable SAR limit.

The invention discloses a selective excitation sequential design method for magnetic resonance imaging in a three-dimensional space. According to the sequential design method disclosed by the invention, a proper excitation K space track is optimally determined according to space sensitive conditions of an excitation target and a plurality of transmitting channels of a radio-frequency coil, thereby a gradient pulse waveform and a radio frequency pulse envelope waveform corresponding to each transmitting channel are determined. A gradient driving unit and a radio-frequency driving unit in a magnetic resonance system can be used for generating gradient pulse and radio frequency pulse according to the radio frequency pulse envelope waveform and the gradient pulse waveform and driving a gradient coil and the radio frequency coil to apply the gradient pulse and radio frequency pulse in a scanning space, thereby the expected selective excitation target in the three-dimensional space is realized.

The invention discloses an antenna array system, a control method and a terminal. The antenna array system comprises an array control module and an antenna array, wherein the array control module is used for controlling the radiation direction of an antenna array pattern to enable a main lobe of the antenna array pattern to face the direction with the maximum base station signal strength; and antenna array is used for transmitting and receiving signals under control of the array control module. Through adjusting the antenna pattern, the main lobe of the antenna radiates towards the base station direction in a non-stop mode, the transmission efficiency of the mobile terminal is improved, and a SAR (Specific Absorption Rate) value is reduced.

In a method for adjustment of a B1 field in a magnetic resonance apparatus, the position of the measurement subject relative to a coordinate system is determined from a plurality of measurement subjects with a morphological magnetic resonance measurement. Three-dimensionally associable measurement subject data are determined from the measurement subject. Respective tissue types of the measurement subject are determined using the three-dimensional measurement subject data and a segmentation of the measurement subject into regions is effected using the tissue types. Known dielectric properties are respectively associated with the tissue types. The segmentation and the association for all positions of the measurement subject are recorded in respective entries of a database, such that the database contains all entries of the measurement subjects. A radio-frequency simulation for an transmission coils is implemented with the entries of the database, with which electrical field distributions and / or B1 field distributions related to spatial elements are determined as a simulation result and are entered as results into the database. For further magnetic resonance examinations, the entries of the database are used for determination of an optimized current distribution for elements of a transmission coil with which the B1 field is ultimately adjusted.

The present disclosure relates to an apparatus and method for transmitting power compensation in a mobile communication terminal. Under a preferred embodiment, a terminal is equipped with a power amplifier, whose output signal amplitude is dependent upon a frequency of an input signal of the power amplifier, an HF connector, an internal antenna and a connection for an external antenna and which is designed to be operated in at least one mobile radio frequency range. The configuration aims to effectively optimize a specific absorption rate value. At least one standard mobile radio frequency range is subdivided into several frequency intervals and power compensation is carried out for at least part of the frequency intervals.

The invention relates to a multilayer super-rapid magnetic resonance imaging method based on segmental excitation space-time coding and relates to the magnetic resonance imaging method. According to the method, an imaging object is divided into multiple segments, at an excitation stage, a 90-degree segment selection sinc pulse is utilized to select an imaging segment, in-segment protons are made to spin through a 180-degree linear frequency modulation pulse to acquire a secondary phase, and time-space coding for the spinning protons in the imaging segment is carried out; the secondary phase information is stored through a phase identical to the 90-degree segment selection pulse; a layer selection 90-degree sinc pulse is connected, decoding and sampling for the protons are carried out. Through designing the center frequency and the decoding sampling gradient of the layer selection pulse, the magnetic resonance data of multiple layers of the segment can be acquired, different imaging segments are selected through correcting the center frequency of the segment selection pulse, and the multilayer data of the whole imaging object is acquired through repeated operation, high resolution reconstruction for the acquired magnetic resonance data of each layer is sequentially carried out, and the multilayer high resolution magnetic resonance image is acquired.

The embodiment of the invention provides a method and a terminal device for regulating antenna transmission power, which are applied to the technical field of communication, so as to solve the problemthat the terminal device mistakenly reduces the transmission power when transmitting radio frequency signals through the antenna. Specifically, the scheme is applied to a terminal device including anantenna.The method comprises the following steps of: acquiring a first image in the case of transmitting a radio frequency signal through an antenna, wherein the first image includes a biometric characteristic of a user; when the biometrics of the user matches the biometrics of the preset head, the transmitting power of the transmitted radio frequency signal is adjusted to be the target power, and the target power is the transmitting power corresponding to the preset head biometrics. The preset biometrics includes user's preset eyebrow feature, preset eye feature, preset nose feature, presetmouth feature and preset ear feature. The scheme is specifically applied to the scenario where the terminal equipment reduces the transmission power of the transmitted radio frequency signal.

An antenna module is provided. The antenna module includes a first slot antenna unit and a second slot antenna unit. The first slot antenna unit is coupled to a radio frequency (RF) unit. The second slot antenna unit is coupled to the RF unit. The first and second slot antenna units are embedded in a wireless communications dongle, and the wireless communications dongle operates as a modem to transmit or receive a wireless signal to or from a wireless telephony communications network for a computer via the first and second slot antenna units when the wireless communication dongle connects to the computer.

The invention relates to a communication device, comprising a first circuit board, a second circuit board and an antenna. The first circuit board is arranged on the second circuit board, and is electrically connected with the second circuit board by a connecting point. The first circuit board comprises a clear zone, a plurality of key pads and a plurality of inductors, wherein the key pads correspond to the clear zone, and the inductors are respectively connected between the key pads in series for regulating the inductance of the key pads. The antenna comprises a radiation metal sheet which corresponds to the clear zone and is positioned at one side of the second circuit board so as to receive and transmit wireless signals. By the communication device, SAR value can be effectively reduced,and the design elasticity of the antenna limited by the design of the dimension of the communication device is increased.

The invention discloses a method for reducing an SAR value of a mobile terminal, a storage medium and the mobile terminal. The method comprises the following steps: in a call process, detecting and comparing the signal strength of an upper antenna and a lower antenna of the mobile terminal in real time; and when it is detected that the signal strength of the upper antenna of the mobile terminal is greater than that of the lower antenna, switching the communication work of the mobile terminal to the upper antenna, and reducing the radio frequency transmitting power of the upper antenna. By adoption of the method disclosed by the invention, the communication work of the mobile terminal is always implemented by the antenna with greater signal strength, and when the upper antenna is switched to implement the communication work of the mobile terminal, the SAR value of the mobile terminal can be reduced by reducing the radio frequency transmitting power of the upper antenna.

The invention provides a mobile terminal and a method for reducing the electromagnetic wave energy absorption ratio thereof. The method comprises the following steps of: determining to arrange a wave-absorbing material on a flexible printed circuit (FPC) of an LCD (Liquid Crystal Display) in the mobile terminal; and attaching the wave-absorbing material to the FPC to absorb the electromagnetic wave energy radiated by an antenna of the mobile terminal. By using a method of adding the wave-absorbing material at the specific position of the mobile terminal, the invention not only reduces the SAR (Synthetic Aperture Radar) value of the mobile terminal, but also ensures that the TRP (Transmission Reference Point) of the mobile terminal is not reduced. Therefore, the influence of the mobile terminal on the human radiation can be reduced on the premise without influencing the calling quality and the appearance of the mobile terminal; meanwhile, the method is easier to realize.

The invention provides an antenna structure, which comprises a double-arm antenna and a main board, wherein the main board is connected with the double-arm antenna and is used for feeding electricity to the double-arm antenna; the double-arm antenna comprises a first arm, a second arm and a coupling branch; the first arm is used for achieving low-frequency resonance; the second arm is used for achieving high-frequency resonance; the first end of the first arm and the first end of the second arm are connected to the main board respectively; the coupling branch is parallel to the second arm and comprises a first branch part and a second branch part; the first branch part and a first part of the second arm are arranged side by side; the first part of the second arm forms one part, extending towards the first end, of the second end of the second arm; and the second branch part extends towards the direction far away from the first end of the second arm relative to the first branch part; and the second branch part is connected with the first arm. According to the antenna structure provided by the embodiment of the invention, the specific absorption rate SAR of the antenna is reduced; and the radiation injury to a human body is reduced.

The invention relates to a terminal antenna for reducing a specific absorption rate (SAR) of a data card and a molding method of the terminal antenna. The terminal antenna has an annular antenna structure connected with the data card, wherein the annular antenna structure at least comprises two sections of parallel slot lines; and the current flow directions in the parallel slot lines are opposite. By the annular arrangement, the SAR of a wireless terminal product is reduced, and the aims of realizing the whole bandwidth and reducing the SAR of a preset frequency range by changing the annular wiring form can be fulfilled under the condition that the bandwidth is guaranteed.

The invention relates to a broadband wireless data card antenna, which is characterized in that antenna cabling and a metal floor collectively form an antenna radiation system, the antenna cabling is directly printed or welded on one surface of a wireless data card main board, and the metal floor is printed on the other surface of the wireless data card main board. The metal corresponding to the orthographic projection area of the antenna cabling on the metal floor is completely hollowed, so that a semi-closed metal-free area is formed on the metal floor, and since a patch of the antenna cabling and the metal floor are respectively arranged on two surfaces of the wireless data card main board, a coupling clearance is conveniently formed between the patch and the metal floor. The clearance coupling between the antenna cabling and the metal floor can play a role of distributive capacitance; and meanwhile, a narrow band in the antenna cabling can play a role of distributive inductance, and the input impedance of the antenna can be effectively adjusted, so that the antenna produces resonance within a needed frequency band to form a wider bandwidth.

The invention provides an antenna capable of reducing an equipment SAR value. The antenna comprises a main circuit board and an antenna circuit board, wherein an adjustable power divider, and a first antenna matching network and a second antenna matching network respectively connected with the adjustable power divider are arranged on the main circuit board, a first antenna and a second antenna are respectively printed on the front and back sides of the antenna circuit board, the first antenna is connected with the first antenna matching network, and the second antenna is connected with the second antenna matching network. Antennas are printed on the front and back sides of an antenna circuit board, and no extra antenna units or devices added on the surrounding of an antenna are needed, thereby simplifying antenna design and saving space. Reconstruction of an antenna directional diagram can be realized through adjusting of a power division network. The SAR value can be effectively reduced through further adjusting antenna radiation direction. Commissioning is flexible, and the performance of an antenna can be optimized by fine tuning antenna wiring and matching elements.

The invention relates to a multi-antenna mobile phone data card capable of reducing specific absorption rate, and a method of the same. The data card comprises a radio frequency substrate, an antenna used for sending and receiving signals and connected between the radio frequency substrate and the antenna, and a feed source for exciting the antenna. The radio frequency substrate is rectangular, the feed source is arranged at a first corner; a second corner, adjacent to the first corner and located at one side of a short edge where the first corner is, is provided with a first hollowed part, the first hollowed part is provided with a first metal strap, one side of the first metal strap is connected with the short edge, and the other end of the metal strap is a free end; and a first electrical length formed from the feed source to the free end of the first metal strap is equal to a second electrical length formed from the feed source to a bottom end of a long edge where the first corner is. According to the invention, by change of the shape of the radio frequency substrate, the electrical lengths from the feed source to several marginal points are respectively equal, current peak and SAR (Specific Absorption Rate) value on the radio frequency substrate are reduced, and structure space is saved, thus, radiation hazard of the data card to human body is reduced.

The present invention relates to a terminal and an antenna layout method for reducing a specific absorption rate. By disposing an offloading antenna which is near a main communications antenna and coupled to the main communications antenna in an opposite direction, a magnetic field around the main communications antenna is impaired, and a field strength of the main communications antenna is reduced, so that the field strength is directly proportional to an SAR value; when the field strength is reduced, the SAR value is reduced, that is, the SAR value is reduced by adding the offloading antenna coupled to the main communications antenna in an opposite direction.

A dome switch assembly that can reduce the SAR value and improve radiation performance of a mobile communication terminal and a mobile communication terminal having the same are provided. The ground layer of the dome switch assembly is connected to a hinge by a hinge contact unit. The hinge contact unit extends through a groove formed in the ground layer towards the inside area of the ground layer and is connected to a bottom surface of the groove. The position and length of the connection of the hinge contact unit to the ground layer may be adjusted so that the SAR value can be reduced and radiation performance can be improved.

The invention relates to electronic equipment. The electronic equipment comprises a circuit board and an antenna device, wherein the antenna device is arranged on one side of the circuit board. The antenna device comprises a radiator and a feed point arranged on the radiator. The circuit board is provided with a circuit area and a vacant area, wherein the circuit area is used for arranging circuitwiring, the circuit area is provided with a feed end, the feed end is electrically connected with the feed point and used for feeding excitation current into the radiator through the feed point, theexcitation current forms a strong current area on the radiator, and the vacant area is arranged opposite to the strong current area. The circuit area surrounds at least part of the outer edge of the vacant area. The vacant area is configured to enable the current of the circuit area to flow to the side away from the vacant area. According to the electronic equipment, the circuit board is providedwith the vacant area, so that the electric field distribution around the circuit board can be improved, SAR hot spots of the antenna device are deviated and dispersed, and the SAR value of the antennadevice is enabled to be relatively low.

There is provided a wireless communication apparatus, including: an antenna including: an antenna element having one end portion that is opened; and a ground conductor to be used as a ground, to which another end portion of the antenna element is connected; a wireless device connected to the antenna; and a blocking member, which is arranged so as to be opposed to the antenna, and is configured to block an electromagnetic wave, wherein the blocking member is arranged so as to, in plan view from the blocking member side in a direction toward the antenna, avoid overlapping at least the one end portion of the antenna element and overlap the another end portion of the antenna element.

The invention provides a wireless communication device which comprises a circuit board, an antenna, a metal module and an inductive reactance module, wherein a feed part and an earthing part are arranged on the circuit board; a clearance area is arranged at the tail end of the circuit board; the antenna is arranged in the clearance area, and electrically connected with the feed part and the earthing part; the metal module is electrically connected with the feed part and the earthing part of the circuit board by the inductive reactance module, and arranged in the clearance area; and the metal module and the antenna are arranged at an interval. According to the wireless communication device, the metal module is arranged in a reasonable position of the clearance area of the antenna, and the energy of an area with higher current distribution on the antenna is reduced by adjusting an inductance value of the inductive reactance module in a fundamental mode without influencing signal transmitting or receiving of the antenna, so that the energy of a hotspot area originally influencing an SAR (Specific Absorption Rate) of the antenna is uniformly dispersed, absorption of an electromagnetic wave by a human body is reduced, and a purpose of reducing the SAR is achieved.

The invention provides an antenna device and a communication device using the antenna device. The communication device comprises a circuit board, a first antenna and a metal sheet. The circuit board is provided with a first feed-in point connected with a high-frequency unit, the first antenna is provided with a first radiation portion coupled with the first feed-in point, the metal sheet is connected with the ground and arranged in a mode of corresponding to a projection shape of the first radiation portion, a gap is arranged between the metal sheet and the first radiation portion, and the metal sheet is larger than or equal to the projection of the first radiation portion in area. The structure is used for reducing SAR values.

The invention relates to an image distortion correction method based on single-scanning mixed space-time coding magnetic resonance imaging. The method is characterized by including the steps that (1)firstly, an area-of-interest of a to-be-imaged object is positioned; (2) a single-scanning mixed space-time coding sequence which is compiled in advance is guided into a nuclear magnetic resonance imager; (3) data sampling is performed; (4) the effective peak value center position of each sampled return wave is determined; (5) the deviation point number of the return wave center position of each return wave peak value center position under the condition relative to the ideal condition in an non-uniform field is calculated; (6) the gradient skewing area caused by skewing of each return wave peak value position in the non-uniform field is calculated; (7) the effective return wave time of each return wave signal is calculated; (8) an equivalent non-uniform-field magnetic susceptibility gradient value Ginh is calculated; and (9) distorted images are corrected through the equivalent non-uniform-field gradient value obtained in the step (8). According to the method, the robustness of a traditional phase coding direction non-uniform field is achieved.

The invention discloses an antenna device and a mobile terminal. The antenna device comprises an antenna conductor, wherein the antenna conductor is provided with a radiation pattern, the radiation patter is provided with a first structure part, a second structure part, a third structure part and a fourth structure part, a first gap part is formed between the first structure part and the second structure part and is used for gap coupling, a second gap part is formed between the third structure part and the fourth structure part and is used for gap coupling, the fourth structure part is connected with the second structure part, the second structure part and the fourth structure part are divided by a feed unit, and a hollow hole is formed in the second structure part. By the antenna device, the technical problem how to form more resonance by arranging branches, gaps and the feed unit is solved, and a specific absorption ratio (SAR) value of an antenna is effectively reduced by holes formed in the branches.

The invention provides an antenna component based on a mobile terminal. The antenna component comprises an antenna arranged in the mobile terminal. The antenna comprises two groups of antenna branches. At least one group of antenna branch is arranged at the lower side of the back surface of the front shell of the mobile terminal. The invention also provides the mobile terminal which is equipped with the antenna component. Compared with the antenna components in the prior art, at least one group of antenna branch is arranged at the lower side of the back surface of the front shell so that the person is enabled to have a certain spatial distance from the antenna when the person is close to the terminal, the radiation of the antenna to the human body can be reduced, the OTA requirements of the antenna can be met and the requirement of reducing the SAR value can be met, the process of using a distance sensor to act as a switch control processor to reduce power can also be eliminated and thus the cost can be reduced.