Abstract: A perpendicular exchange biased device comprises a layer of buffer material on a surface of a substrate, a layer of ferromagnetic material on a surface of the buffer layer, wherein the magnetization of the ferromagnetic layer lies in a direction perpendicular to the plane of the layer of ferromagnetic material, and a layer of antiferromagnetic material on a surface of the layer of ferromagnetic material. A method of making a perpendicular exchange biased device comprising positioning a layer of buffer material on a surface of a substrate, positioning a layer of ferromagnetic material on a surface of the layer of buffer material, wherein the magnetization of the ferromagnetic layer lies in a direction perpendicular to the plane of the layer of ferromagnetic material, and positioning a layer of antiferromagnetic material on a surface of the layer of ferromagnetic material is also included.

Abstract: A write pole for a magnetic recording head, such as a perpendicular magnetic recording head, includes a first layer of material adjacent a second layer of material. In one embodiment, the first layer of material has a saturation magnetic moment less than about 1.0 T and the second layer of material has a saturation magnetic moment greater than the saturation magnetic moment of the first layer of material. The first layer of material may include (NiFe)100−yXy, wherein X comprises Cr, Cu and/or Ti and wherein y is in the range of about 2 to about 50.

Abstract: A write head for a disk drive includes a first layer of magnetic material having a fixed magnetization aligned in a first direction, a second layer of magnetic material having a changeable magnetization aligned in a quiescent state in a second direction orthogonal to the first direction, a first non-magnetic layer positioned between the first layer of magnetic material and the second layer of magnetic material, electrodes for connection to a current supply for passing an electric current through the first layer of magnetic material, the first non-magnetic layer, and the second layer of magnetic material for switching the changeable magnetization of the second layer, and an arm for positioning a first edge of the second layer of magnetic material adjacent to a magnetic recording medium, whereby the magnetization of the second layer of magnetic material affects magnetization of the magnetic recording medium.

Abstract: A method for pre-compensating an analog signal in a composite digital audio broadcasting signal including the analog signal and a plurality of digitally modulated sub-carrier signals, the method comprising the steps of sampling the analog signal to obtain successive blocks of samples, demodulating each of the blocks of samples to obtain a plurality of demodulator outputs, remodulating the demodulator outputs that correspond to the predetermined ones of the digitally modulated sub-carrier signals to produce an error signal, subtracting the error signal from the one of the blocks of samples to produce a pre-compensated block of samples, and combining the pre-compensated block of samples with a plurality of OFDM pulses to produce a compensated composite signal. An apparatus for performing the method is also included.

Abstract: An apparatus for producing a small spot of optical energy comprises a planar waveguide shaped to direct a linearly polarized electromagnetic wave to a focal point within the waveguide, and a metallic pin positioned at the focal point whereby the linearly polarized electromagnetic wave creates surface plasmons on a surface of the pin. The apparatus can further comprise means for phase shifting a portion of the linearly polarized electromagnetic wave. Recording heads comprising a magnetic write pole, a planar waveguide positioned adjacent to the magnetic write pole, the planar waveguide being shaped to direct a linearly polarized electromagnetic wave to a focal point within the waveguide, and a metallic pin positioned at the focal point whereby the linearly polarized electromagnetic wave creates surface plasmons on a surface of the pin, and disc drives that use such recording heads are also disclosed.

Abstract: A write head for writing information bits to magnetic storage media includes a first write pole for producing a first magnetic field in a first direction and a second write pole for producing a second magnetic field such that the combined field from the two poles lies either substantially along the first direction or in a second direction that is substantially orthogonal to the first direction. The second write pole includes a free layer having magnetization controlled by spin transfer torque, and a first spacer positioned between the free layer and the first write pole. The write head can further include a pinned layer and a second spacer positioned between the pinned layer and the free layer. A disc drive that includes the write head and a method of writing to magnetic storage media that utilizes the write head are also included.

Abstract: A method of manufacturing a thin film of magnetic material, comprises sputtering magnetic material from a target to a substrate to form a thin film of the magnetic material on the substrate, wherein the ratio of sputtering power in Watt to sputtering pressure in mTorr is greater than one. Thin films of magnetic material made according to the method and magnetic storage media including a thin film of magnetic material made according to the method are also included.

Abstract: An apparatus for providing environmental control, secondary power and emergency power for an aircraft, comprises a cooling turbine coupled to a first electromechanical machine rotor, and including an input for receiving compressed air or ram air, and an output for discharging cooled air or exhaust air; a compressor coupled to a second electromechanical machine rotor, and including an input for receiving engine bleed air or ambient air, and an output for discharging compressed air; means for magnetically coupling the first and second rotors; a power turbine coupled to the compressor; a heat exchanger connected between the compressor output and the cooling turbine input; and a control unit for controlling the magnetic coupling between the first and second rotors.

Abstract: A read head for use with magnetic recording media having a plurality of magnetic tracks includes a read sensor, first and second magnetic lead shields for improving track resolution, and first and second magnetic shields for improving linear resolution. The read sensor is formed on a side wall of one of the first and second magnetic lead shields using a technique such as ion beam deposition for enhanced film growth rate on the side wall. A magnetic disc drive storage system incorporating the read head and a method of making the read head are also included.

Abstract: A spin valve read element for use with, for example, magnetic recording media, includes a permanent magnet as one of the multilayers that make up the spin valve. The spin valve may also include a pinned ferromagnetic layer, an antiferromagnetic coupling inducing layer, a reference ferromagnetic layer, an electroconductive layer, and/or a free ferromagnetic layer. Epitaxy breaking layers may also be advantageously positioned within the spin valve. The multilayers of the spin valve may be constructed as a current perpendicular to the plane or a current parallel to the plane type spin valve.

Abstract: A method is provided for transmitting a composite digital audio broadcast signal having an analog portion and a digital portion to mitigate intermittent interruptions in the reception of said digital audio broadcast signal. The method comprises the steps of arranging symbols representative of the digital portion of the digital audio broadcast signal into a plurality of audio frames, producing a plurality of modem frames, each of the modem frames including a group of the audio frames, and adding a frame synchronization signal to each of the modem frames. The modem frames are then transmitted along with the analog portion of the digital audio broadcast signal, with the analog portion being delayed by a time delay corresponding to an integral number of the modem frames. The invention also encompasses radio receivers and transmitters which process signals according to the above methods.

Abstract: A method for transmission of compressed data for a digital audio broadcasting system comprises the steps of producing digital information representative of an audio signal; estimating the number of bits to be allocated to the digital information in a modem frame; encoding the digital information within the estimated number of bits to produce encoded data; removing selected bits from the encoded data; adding bits corresponding to digital messages to the encoded information to form a composite modem frame; formatting the composite modem frame bits to produce formatted composite modem frame bits; and transmitting the formatted composite modem frame bits. The invention also encompasses transmitters that perform the method.

Abstract: A recording head for use in conjunction with a magnetic storage medium, comprises a waveguide for providing a path for transmitting radiant energy, a near-field coupling structure positioned in the waveguide and including a plurality of arms, each having a planar section and a bent section, wherein the planar sections are substantially parallel to a surface of the magnetic storage medium, and the bent sections extend toward the magnetic storage medium and are separated to form a gap adjacent to an air bearing surface, and applying a magnetic write field to sections of the magnetic recording medium heated by the radiant energy. A disc drive including the recording head and a method of recording data using the recording head are also provided.

Abstract: A method for making a magnetic sensor for a disk drive read head, the method comprising the steps of depositing a magnetoresistive stack on a surface of a first layer of material, depositing a resist layer on a first portion of the magnetoresistive stack, removing a second portion of the magnetoresistive stack not covered by the resist layer, depositing a layer of additional material on the magnetoresistive stack, the resist material, and the surface of the first layer, removing the additional material from sidewalls of the resist material, and using a lift-off process to remove the resist material. Magnetic sensors made by the above process are also included.

Abstract: A navigation system for an unmanned aerial vehicle, the navigation system comprising a first antenna for receiving a global positioning system signal, a first interference suppression unit coupled to the first antenna, the first interference suppression unit suppressing interference in the global positioning system signal using a first interference suppression technique, a first navigation unit for receiving signals from the first interference suppression unit, a second antenna for receiving the global positioning system signal, a second interference suppression unit coupled to the second antenna, the second interference suppression unit suppressing interference in the global positioning system signal using a second interference suppression technique, and a second navigation unit for receiving signals from the second interference suppression unit. A method for controlling the flight of an air vehicle performed by the apparatus is also included.

Abstract: A write head comprises a yoke including a top pole and a bottom pole, the top pole including a layer of insulating material, a layer of a first magnetic material positioned on a surface of the layer of insulating material, the first magnetic material having a first end positioned adjacent to an air bearing surface of the write pole, and a layer of a second magnetic material positioned on the surface of the layer of insulating material, the second magnetic material having a lower magnetic moment than the first magnetic material and being positioned to conduct magnetic flux between the return pole and the layer of first magnetic material. The method of constructing the write head and a disc drive including the write head are also included.

Abstract: This invention provides a method for reducing radio frequency interference in an FM in-band on-channel digital audio broadcasting receiver. The method comprises the steps of receiving a composite signal including a signal of interest and an interfering signal, demodulating the composite signal to produce a first demodulated signal, computing a first binary soft decision from the first demodulated signal, processing the composite signal to produce a processed signal, demodulating the processed signal to produce a second demodulated signal, computing a second binary soft decisions from the second demodulated signal, and combining the first and second binary soft decisions to produce an output signal. Radio receivers that utilize the above method are also included.

Abstract: A method of recording information bits in a magnetic storage medium, the method comprising positioning a first conductor adjacent to a magnetic recording medium, the conductor having a width and a length, wherein a distance between the first conductor and the magnetic recording medium is less than or equal to the width and the length, and passing a first current through the conductor of sufficient magnitude to produce a magnetic field in the magnetic medium greater than one Tesla and having a magnetic field gradient in a cross track direction and a down track direction greater than 100 Oe/nm over a bit dimension. The thickness of the first conductor can be less than or equal to the distance between the first conductor and the magnetic recording medium. The current density in the conductor can be greater than 109 ampere/cm2, and the length of the conductor can be less than 100 nm. The current can be applied as one or more pulses in a predetermined clock cycle time.

Abstract: A method of pre-compensating for pulse overlap in a digitally modulated signal comprises the steps of receiving a sequence of pulses, modulating the pulses to produce a first sequence of modulated pulses, demodulating the first sequence of modulated pulses to produce a first sequence of demodulated pulses, combining the first sequence of demodulated pulses with the first sequence of pulses to produce a first sequence of error pulses, modulating the first sequence of error pulses to produce a first sequence of modulated error pulses, and combining the first sequence of modulated error pulses with the first sequence of modulated pulses to produce a first sequence of compensated pulses.

Abstract: This invention provides a method for reducing FM interference in an in-band on-channel digital audio broadcasting system. The method includes the steps of receiving a composite signal including a signal of interest and an interfering signal and normalizing the composite signal to produce a normalized composite signal. The composite signal is then multiplied by the complex conjugate of the normalized composite signal to produce a real signal. Then the real signal is filtered and the resulting filtered signal is multiplied by the normalized composite signal to produce an output signal. The adverse effects of the interfering signal in the output signal are reduced with respect to the magnitude of the signal of interest reducing FM interference in an in-band on-channel digital audio broadcasting system, thereby making it easier to detect the signal of interest.