Having Magnetostrictive-type Amplifying Device Patents (Class 330/60)
  • Publication number: 20090322419
    Abstract: An amplifying apparatus includes a magneto-resistive device which has a magnetic free layer, a magnetic pinned layer having a magnetic moment larger than that of the magnetic free layer, and an intermediate layer provided in between the magnetic free layer and the magnetic pinned layer. The amplifying apparatus has a first electrode layer provided in a magnetic free layer side of the magneto-resistive device, and a second electrode layer provided in a magnetic pinned layer side of the magneto-resistive device. The amplifying apparatus further includes a direct-current bias power-source for applying a direct-current bias to the magneto-resistive device, and a load resistor. The amplifying apparatus continually causes the change of a magnetization direction of the magnetic free layer to make the magneto-resistive device show negative resistance, and thereby amplifies an input signal.
    Type: Application
    Filed: July 20, 2009
    Publication date: December 31, 2009
    Inventors: Hiroki Maehara, Hitoshi Kubota, Akio Fukushima, Shinji Yuasa, Yoshishige Suzuki, Yoshinori Nagamine
  • Patent number: 7212749
    Abstract: An Improved Signal Receiver Having Wide Band Amplification Capability is disclosed. Also disclosed is a receiver that is able to receive and reliably amplify infrared and/or other wireless signals having frequency bandwidths in excess of 40 MHz. The receiver of the present invention reduces the signal-to-noise ratio of the received signal to ?th of the prior systems. The preferred receiver eliminates both the shunting resistor and the feedback resistor on the input end by amplifing the signal in current form. Furthermore, the receiver includes transconductance amplification means for amplifying the current signal without the need for Cascode stages. Finally, the receiver includes staged amplification to amplify the current signal in stages prior to converting the signal into a voltage output.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: May 1, 2007
    Assignee: ZiLOG, Inc.
    Inventors: T. Allan Hamilton, Alan Grace
  • Patent number: 5619386
    Abstract: An arrangement for reading out an information signal from a magnetic record carrier. The arrangement includes a read head having a magneto-resistive (MR) element (R.sub.m1) with a first terminal (3) connected to a first point (13) of constant potential, and a second terminal (4); a bias-current generator (2) having an output (5) for supplying a bias-current to the MR element; and an amplifier circuit (1) having a first terminal (6) coupled to the output (5) of the bias-current generator (2), and a second terminal (7) coupled to the second terminal (4) of the magneto-resistive element (R.sub.m1) so as to form a series arrangement of the bias-current generator, the amplifier circuit and the magneto-resistive element. At an output terminal (8), the information signal is available. The amplifier circuit (1) includes a MOS transistor T.sub.1 coupled between the output terminal (8) and the second terminal (7), and a feedback circuit, including a resistor (R.sub.1) and a capacitor (C.sub.
    Type: Grant
    Filed: October 5, 1994
    Date of Patent: April 8, 1997
    Assignee: U.S. Philips Corporation
    Inventors: Johannes O. Voorman, Joao N. V. L. Ramalho
  • Patent number: 5373741
    Abstract: An ultrasonic measuring device that is especially suited to nondestructive testing of materials is fitted with an ultrasound test head 72, a transmitter (74) and a receiver (76) that is characterized by a broadband logarithmic amplifier (78). This amplifier consists of several amplifier stages that are identical in construction and connected in series. Each amplification stage is characterized by the fact that it contains two transistorized individual amplifiers, namely a first and a second differential amplifier that are connected to one another and whose transistors (20, 22; 24, 26) are each interconnected at their base and at their collector. Each of these transmitters is connected at the emitters via inverse feedback resistors (34, 36; 40, 42) to a constant-current source (46, 50).
    Type: Grant
    Filed: June 24, 1993
    Date of Patent: December 20, 1994
    Assignee: Krautkramer GmbH & Co.
    Inventors: Klaus Volkmann, Horst Pollok, Manfred Kickartz