Patent classifications
G01R33/0029
Radio-frequency coil signal chain for a low-field MRI system
A radio-frequency (RF) coil for use in a low-field magnetic resonance imaging system and methods of making the same are provided. The RF coil may include a conductor arranged on a substrate in an arrangement such that symmetry in the arrangement cancels at least a portion of a common mode voltage when a current is passed through the conductor. The RF coil may be included in a magnetic resonance imaging (MRI) system for imaging a patient having at least one B.sub.0 magnet for generating a B.sub.0 magnetic field.
Magnetic sensor
A magnetic sensor that includes a Hall element; a switch circuit configured to switch a direction of a drive current supplied to the Hall element between a first direction and a second direction; a magnetic field detection circuit configured to execute a detection operation for detecting a target magnetic field acting on the Hall element, based on a first difference between a Hall voltage generated in the Hall element when the drive current is supplied to the Hall element in the first direction and a Hall voltage generated in the Hall element when the drive current is supplied to the Hall element in the second direction; and a test magnetic field generation circuit configured to generate a test magnetic field different from the target magnetic field in a test operation.
Semiconductor device
The semiconductor device includes a Hall element, a first differential pair, a second differential pair, an output amplifier circuit, and a voltage divider circuit. The Hall element outputs a signal that is dependent on stress to be applied to a semiconductor substrate to the first differential pair. The voltage divider circuit divides a voltage into a divided voltage having a voltage dividing ratio that is dependent on the stress. The first differential pair outputs a first current based on the signal. The second differential pair outputs a second current based on the divided voltage and a reference voltage. The output amplifier circuit outputs a voltage based on the first and second currents. A gain of the output amplifier circuit is approximated by a sum of a difference between stress dependence coefficients of transconductances of the first and second differential pairs and a stress dependence coefficient of the voltage dividing ratio.
Reducing stray magnetic-field effects using a magnetic-field closed-loop system
In one aspect, a magnetic-field sensor includes main coil circuitry configured to generate a first magnetic field signal at a first frequency. A reflected signal is generated from a target caused by the first signal generated by the main coil circuitry. The magnetic field sensor also includes magnetoresistance circuitry configured to receive an error signal. The error signal is formed from a combination of the reflected signal and a second magnetic field signal. The magnetic-field sensor further includes analog circuitry configured to receive an output signal from the magnetoresistance circuitry, digital circuitry configured to receive an output signal from the analog circuitry, a mixer configured to receive a feedback signal from one of the digital circuitry or the analog circuitry, and secondary coil circuitry configured to receive a driver signal from the mixer causing the secondary coil circuitry to generate the second magnetic field signal at the first frequency.
ELECTRONIC DEVICE FOR PROVIDING INDOOR POSITIONING AND METHOD THEREFOR
An electronic device is provided. The electronic device includes a display, a camera, and a processor operatively connected to the display and the camera. The processor may display an augmented reality on the display on the basis of an image captured by the camera, may display a point on the display so as to move on the augmented reality while interworking with the movement of the electronic device, may recognize a selected spot on the augmented reality, may display a guide area on the augmented reality, the guide area including the selected spot such that the point moves within a specific area, may store sensor information including a geomagnetic value measured while the point moves within the guide area, may store radio signal intensity information measured while the point moves within the guide area, and may correct a geomagnetic value included in the sensor information.
Magnetic field sensor arrangement and method for processing a magnetic field sensor output signal
A magnetic field sensor arrangement includes a magnetic field sensor element configured to provide a sensor output signal responsive to a magnetic field, wherein the sensor output signal is representative of a magnetic field amplitude; a processing module configured to provide a processed sensor output signal representative of the sensor output signal; a switching level calculation module configured to calculate a switching level, (1) during a power up mode, based on a default switching level, and (2) during a running mode, based on the processed sensor output signal; a comparator module configured to compare the processed sensor output signal with the switching level, and to provide a comparator output signal based on the comparison; and a storage module configured to store the default switching level, provide the default switching level during the power up mode, and update the default switching level during the running mode.
Magnetism detection device
A magnetism detection device according to an embodiment of the disclosure includes a sensor section and a resistive section. The sensor section includes a first magnetism detection element. The first magnetism detection element has a first stacked structure and is configured to detect a magnetic field to be detected. The resistive section includes a first resistive element and is coupled to the sensor section. The first resistive element has the first stacked structure.
MAGNETIC SENSOR FOR MEASURING AN EXTERNAL MAGNETIC FIELD ANGLE IN A TWO-DIMENSIONAL PLANE AND METHOD FOR MEASURING SAID ANGLE USING THE MAGNETIC SENSOR
Magnetic sensor for measuring an external magnetic field angle in a two-dimensional plane, including: a first and second sensing unit outputting, respectively, a first signal sin(θ) and a second signal cos(θ); a first multiplying DAC receiving the first signal and a first digital input sin(f*t) and outputting a first modulated output signal; a second multiplying DAC receiving the second signal and a second digital input cos(f*t) and outputting a second modulated output signal; a first RC filter receiving the first modulated output signal and outputting a first filtered signal sin(θ)*sin(f*t+RCd); a second RC filter receiving the second modulated output signal and outputting a second filtered signal sin(θ)*sin(f*t+RCd); an adder adding the first and second filtered signals and outputting a summed signal cos(f*t+RCd+θ); and an angle extracting unit for measuring the phase delay between the summed signal and a synchronization signal and determining the angle from the phase delay.
MAGNETIC LOGIC UNIT (MLU) CELL FOR SENSING MAGNETIC FIELDS WITH IMPROVED PROGRAMMABILITY AND LOW READING CONSUMPTION
A magnetic logic unit (MLU) cell for sensing magnetic fields, including: a magnetic tunnel junction including a storage layer having a storage magnetization, a sense layer having a sense magnetization; a tunnel barrier layer between the storage layer and the sense layer; and a pinning layer pinning the storage magnetization at a low threshold temperature and freeing it at a high threshold temperature. The sense magnetization is freely alignable at the low and high threshold temperatures and the storage layer induces an exchange bias field magnetically coupling the sense layer such that the sense magnetization tends to be aligned antiparallel or parallel to the storage magnetization. The tunnel barrier layer is configured for generating an indirect exchange coupling between the tunnel barrier layer and the sense layer providing an additional exchange bias field.
MAGNETIC FIELD SENSOR AND APPARATUS FOR MEASURING MAGNETIC FIELD
A magnetic field sensor of the present invention includes a first electrode including a magnetic material, a second electrode including a non-magnetic material, a common electrode disposed between the first electrode and the second electrode and connected to a ground terminal, a power supplier of which one end is connected to the first electrode and the second electrode and of which another end is connected to the common electrode to supply power of a frequency band required, a variable resistor configured to control at least one of a resistance value between the first electrode and the power supplier or a resistance value between the second electrode and the power supplier, and a differential amplifier connected to the first electrode through a positive terminal and connected to the second electrode through a negative terminal to output a difference value between a first capacitance generated by the first electrode and a second capacitance generated by the second electrode in response to external application of a magnetic field.