Abstract: A method of manufacturing a cathode active material for a lithium secondary battery according to embodiments of the present invention includes performing a first heat treatment on a first mixture of a transition metal precursor and a lithium precursor at a first calcination temperature to obtain a preliminary lithium-transition metal composite oxide particle; and performing a second heat treatment on a second mixture obtained by adding the lithium precursor to the preliminary lithium-transition metal composite oxide particle at a second calcination temperature which is lower than the first calcination temperature to form a lithium-transition metal composite oxide particle.

Abstract: An embodiment includes: a base; a circuit board which is disposed on the base and which includes first and second terminals; a housing disposed on the circuit board; a bobbin disposed in the housing; a first coil disposed on the bobbin; a sensing magnet disposed on the bobbin; a magnet disposed in the housing; a first position sensor which is disposed in the housing and which corresponds to the sensing magnet; a second coil disposed between the base and the magnet; and a second position sensor which is disposed on the circuit board and which includes a first sensor and a second sensor, wherein each of the first sensor and the second sensor is a driver integrated circuit including a hall sensor and a driver, a clock signal is provided to the first terminal of the circuit board, a data signal is provided to the second terminal of the circuit board, and the driver of each of the first position sensor, the first sensor, and the second sensor transmits/receives the clock signal through the first terminal of the ci

Abstract: The spindle motor includes a rotating shaft, a rotor cover which is secured to the rotating shaft and rotates the rotating shaft, a bearing for rotatably supporting the rotating shaft, a holder for holding the bearing, and a holding magnet which is directly mounted to an inner wall of the rotor cover. In this case, the holding magnet is positioned above the bearing to prevent oil from being discharged from the bearing to the outside.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A conductive H-shaped impedance matching element matches a source impedance to an antenna impedance. The impedance matching element having a feed terminal at the center thereof from which current is supplied to the two filars of each filar pair disposed about an edge of the impedance matching element and symmetric with respect to a center of the impedance matching element. The impedance matching element further comprises a reactive element for matching the antenna and source impedances.

Abstract: Disclosed herein is a spindle motor. The spindle motor includes a rotating shaft, a rotor cover which is secured to the rotating shaft and rotates the rotating shaft, a bearing for rotatably supporting the rotating shaft, a holder for holding the bearing, and a holding magnet which is directly mounted to an inner wall of the rotor cover. In this case, the holding magnet is positioned above the bearing to prevent oil from being discharged from the bearing to the outside.

Abstract: The spindle motor includes a rotating shaft, a rotor cover which is secured to the rotating shaft and rotates the rotating shaft, a bearing for rotatably supporting the rotating shaft, a holder for holding the bearing, and a holding magnet which is directly mounted to an inner wall of the rotor cover. In this case, the holding magnet is positioned above the bearing to prevent oil from being discharged from the bearing to the outside.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A conductive H-shaped impedance matching element matches a source impedance to an antenna impedance. The impedance matching element having a feed terminal at the center thereof from which current is supplied to the two filars of each filar pair disposed about an edge of the impedance matching element and symmetric with respect to a center of the impedance matching element. The impedance matching element further comprises a reactive element for matching the antenna and source impedances.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A conductive H-shaped impedance matching element matches a source impedance to an antenna impedance. The impedance matching element having a feed terminal at the center thereof from which current is supplied to the two filars of each filar pair disposed about an edge of the impedance matching element and symmetric with respect to a center of the impedance matching element. The impedance matching element further comprises a reactive element for matching the antenna and source impedances.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A conductive H-shaped impedance matching element matches a source impedance to an antenna impedance. The impedance matching element having a feed terminal at the center thereof from which current is supplied to the two filars of each filar pair disposed about an edge of the impedance matching element and symmetric with respect to a center of the impedance matching element. The impedance matching element further comprises a reactive element for matching the antenna and source impedances.

Abstract: A quadrifilar helical antenna comprising two pairs of filars having unequal lengths and phase quadrature signals propagating thereon. A conductive H-shaped impedance matching element matches a source impedance to an antenna impedance. The impedance matching element having a feed terminal at the center thereof from which current is supplied to the two filars of each filar pair disposed about an edge of the impedance matching element and symmetric with respect to a center of the impedance matching element. The impedance matching element further comprises a reactive element for matching the antenna and source impedances.

Abstract: An antenna structure for use in a communications device for reducing a user's SAR exposure. In addition to the conventional antenna elements, e.g., a radiating element and a ground plane, the antenna structure of the present invention comprises a conductive element for directing radio frequency energy emitted by the radiating element away from the user, thereby reducing the user's SAR exposure. The conductive element can be disposed on an interior or an exterior surface of a case enclosing the communications device.