634 results about "Magnetic dipole" patented technology

A transmitter antenna assembly for transient electromagnetic well logging instrument comprises an antenna coil coupled with a current source and a magnetic core having residual magnetization. Switching current in the antenna coil results in magnetization reversal in the magnetic core and change in magnetic dipole moment of the antenna. After the magnetization reversal is complete the current is removed and the new vector of magnetic dipole of the antenna maintains constant (steady-state phase of the antenna dipole) due to magnetic hysteresis of magnetic material employed for the magnetic core. No power expenditure during the steady-state phase of the magnetic dipole facilitates highly effective generation and fast switching of a large magnetic dipole. The magnetic core also serves as a shield between the antenna coil and any conductive part of the antenna assembly. Embodiments suitable for measurement-while-drilling or measurements through casing make use of residual magnetization of magnetic drill collar or magnetic casing respectively.

A method and apparatus for generating a controlled torque of a desired direction and magnitude in an object within a body, particularly in order to steer the object through the body, such as a catheter through a blood vessel in a living body, by producing an external magnetic field of known magnitude and direction within the body, applying to the object a coil assembly including preferably three coils of known orientation with respect to each other, preferably orthogonal to each other, and controlling the electrical current through the coils to cause the coil assembly to generate a resultant magnetic dipole interacting with the external magnetic field to produce a torque of the desired direction and magnitude.

Methods and apparatus for making directional measurements of earth formations surrounding a borehole. New antenna coil shield designs are utilized to provide selective attenuation of at least one electromagnetic energy field component as the component interacts with the shield. The new shields are implemented in several downhole tool configurations to provide azimuthally focused formation measurements. In effect, the new shield filters interacting electromagnetic energy field components to pass those components corresponding to a magnetic dipole oriented at an angle from the tool axis. The shields thereby alter a coil's envelope of influence to electromagnetic energy. The new shields also form part of a system for making directional measurements while drilling.

A method is provided for determining an electric conductivity of an earth formation formed of different earth layers, which earth formation is penetrated by a wellbore containing a wellbore fluid, is provided. The method includes the steps of: lowering an induction logging tool into the wellbore to a location surrounded by a selected one of the earth layers, the tool having a magnetic field transmitter effective to induce magnetic fields of different frequencies in the earth formation, and a magnetic field receiver effective to receive response magnetic fields and to provide a signal representative of each response magnetic field, at least one of the transmitter and the receiver having a plurality of magnetic dipole moments in mutually orthogonal directions. At least two of the different frequencies are selected, and for each selected frequency, the transmitter is operated so as to induce a magnetic field in the earth formation and the receiver is operated so as to provide a signal representing a response magnetic field, wherein the at least one of the transmitter and receiver is operated in the mutually orthogonal directions. The signals are combined in a manner so as to create a combined signal having a reduced dependency on the electric conductivity in the wellbore region. The formation resistivity and the relative orientation of the logging tool with respect to the formation layering is determined from the combined signal.

A high-frequency oscillation element has a ferromagnetic material which exhibits thermal fluctuation of magnetization and generates spin fluctuations in conduction electrons, a nonmagnetic conductive material which is laminated on the first magnetic material and transfers the conduction electrons, a magnetic material which is laminated on the nonmagnetic conductive material, generates magnetic resonance upon injection of the conduction electrons, and imparts magnetic dipole interaction to magnetization of a neighboring magnetic area by means of magnetic vibration stemming from the magnetic resonance, a first electrode electrically coupled with the first magnetic material, and a second electrode electrically coupled with the second magnetic material.

A system and method for embedding tracking technology in a medical table is disclosed. A plurality of table sensors is attached to a medical table to form an array. An instrument sensor is attached to an instrument. At least one of the table sensors and the instrument sensor generates at least one magnetic dipole field. The instrument sensor is moved relative to the array while at least one of the table sensors and the instrument sensor measures at least one vector component of the field. The measured vector component(s) are communicated to tracker electronics that determine at least one of a position and orientation of the instrument sensor relative to the array.

An electromagnetic antenna for Measurement-While-Drilling (MWD) applications is disclosed. The antenna can include several array elements that can act alone or together in various measurement modes. The antenna elements can be disposed in tool body recesses to be protected from damage. The antenna elements can include a ferrite plate crossed or looped by independent current carrying conductors in two or more directions forming a bi-directional or crossed magnetic dipole. Although disclosed as a MWD system conveyed by a drill string, basic concepts of the system are applicable to other types of borehole conveyance.

A magnetic anomaly sensing system and method uses at least four triaxial magnetometer (TM) sensors with each of the TM sensors having X,Y,Z magnetic sensing axes. The TM sensors are arranged in a three-dimensional array with respective ones of the X,Y,Z magnetic sensing axes being mutually parallel to one another. The three-dimensional array defines a geometry that forms at least one single-axis gradiometer along each of the X,Y,Z magnetic sensing axes. Information sensed by the TM sensors is to generate scalar magnitudes of a magnetic anomaly field measured at each of the TM sensors, comparisons of the scalar magnitudes to at least one threshold value, distance to a source of the magnetic anomaly field using the scalar magnitudes when the threshold value(s) is exceeded, and a magnetic dipole moment of the source using the distance.

A low-loss, high-efficiency, broadband antenna including both electric and magnetic dipole radiators is provided herein. The broadband antenna may be referred to as a “P×M antenna” and may generally include a ground plane; a magnetic radiator formed within the ground plane; a conductive feed arranged within a first plane, which is parallel to the ground plane; and an electric radiator arranged within a second plane, which is perpendicular to the ground plane and coupled at one end to the conductive feed. According to a particular aspect of the invention, the electric and magnetic radiators are substantially complementary to one another and are coupled for producing a P×M radiation pattern over a broad range of operating frequencies. One advantage of the P×M antenna described herein is that the complementary antenna elements are combined without the use of a lossy, resistive matching network, thereby increasing the efficiency with which the P×M radiation pattern is produced.

The invention provides apparatus having a series of individual plasma excitation devices each constituted by a wire applicator of microwave energy, having one end connected to a source for producing microwave energy and having an opposite end fitted with at least one magnetic dipole for creating at least one surface having a magnetic field that is constant and of intensity corresponding to electron cyclotron resonance, the dipole being mounted at the end of the microwave applicator in such a manner as to ensure that electrons accelerated to electron cyclotron resonance oscillate between the poles so as to create a plasma diffusion zone situated on the side of the dipole that is remote from the end of the applicator, the individual excitation devices being distributed relative to one another and in proximity with the work surface so as to create together a plasma that is uniform for the work surface.

A magnetic arrangement is described for an implantable system for a recipient patient. A planar coil housing contains a signal coil for transcutaneous communication of an implant communication signal. A first attachment magnet is located within the plane of the coil housing and rotatable therein, and has a magnetic dipole parallel to the plane of the coil housing for transcutaneous magnetic interaction with a corresponding second attachment magnet.

It is described an electron optical arrangement, a X-ray emitting device and a method of creating an electron beam. An electron optical apparatus (1) comprises the following components along an optical axis (25): a cathode with an emitter (3) having a substantially planar surface (9) for emitting electrons; an anode (11) for accelerating the emitted electrons in a direction essentially along the optical axis (25); a first magnetic quadrupole lens (19) for deflecting the accelerated electrons and having a first yoke (41); a second magnetic quadrupole lens (21) for further deflecting the accelerated electrons and having a second yoke (51); and a magnetic dipole lens (23) for further deflecting the accelerated electrons.

Techniques for implementing antenna configurations with substantially co-located axes are disclosed. A method for constructing co-located antennas includes winding a first antenna on a support, the first antenna having a first magnetic dipole in a first orientation; and winding a second antenna on the support through a first set of openings in the support, the second antenna having a second magnetic dipole in a second orientation, wherein the first orientation is different from the second orientation, and wherein a center of the first magnetic dipole substantially co-locates with a center of the second magnetic dipole.

An antenna having a driven element coupled to multiple additional elements to resonate at multiple frequencies. A magnetic dipole mode is generated by coupling a driven element to a second element, and additional resonances are generated by coupling additional elements to either or both of the driven or second element. One or multiple active components can be coupled to one or more of the coupled elements to provide dynamic tuning of the coupled or driven elements.

A modal antenna is formed within a battery assembly for use with a portable electronic device. In certain embodiments, the antenna is printed on an exterior surface of a battery enclosure using a conductive ink. In other embodiments, the antenna is attached, or etched, on a substrate; the substrate may at least partially include a battery housing. The antenna can include an Isolated Magnetic Dipole (IMD) antenna, or other radiating structure. Active components, such as active tuning components, are optionally included in the antenna-integrated battery assembly for the purpose of tuning the antenna.

A magnetic anomaly sensing system uses triaxial magnetometer (TM) sensors arranged in a three-dimensional array. A processor coupled to the TM sensors generates partial gradient contraction data, and complete gradient tensor data and corresponding complete gradient contraction data. The generated data can be used to align the three-dimensional array with a magnetic target. Once the three-dimensional array is aligned with the magnetic target, the generated data can be used to uniquely determine (i) distance to the magnetic target, (ii) position of the magnetic target relative to the three-dimensional array, and (iii) the magnetic dipole moment of the magnetic target.

Provided are a touch screen and a method of operating the same. The touch screen includes a detecting part, a control part, and a tactile feedback part. The detecting part detects object's approach or contact. The control part receives a signal of the detecting part to output a feedback signal. The tactile feedback part receives the feedback signal of the control part to provide a tactile feedback to a contact position using a magnetic force. The tactile feedback uses the magnetic force of a magnetic dipole.

The spiral sheet antenna allows a small efficient antenna structure that is much smaller than the electromagnetic wavelength. It achieves the small size by introducing a high effective dielectric constant through geometry rather than through a special high dielectric constant material. It typically includes a rectangular cylinder-like shape, with a seam. The edges of the seam can overlap to make a high capacitance, or they can make a high capacitance by simply having the edges of the seam very close to each other. The high capacitance serves the same role as a high dielectric constant material in a conventional compact antenna.