Compensating For Inter-electrode Impedance (e.g., Neutralization) Patents (Class 330/76)
  • Patent number: 8374279
    Abstract: A modulation device includes a signal input for receiving a data stream to be modulated and a first and a second signal output. At least one first complex component is derived from the data stream in a coding device. A first and a second high-frequency signal are output via the signal outputs. The first and second high-frequency signals are derived from the at least one first complex component and are distinguished by the fact that the second high-frequency signal has a phase shift of substantially 90° with respect to the first high-frequency signal.
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: February 12, 2013
    Assignee: Intel Mobile Communications GmbH
    Inventors: Bernd Adler, André Hanke
  • Publication number: 20120326779
    Abstract: An amplifier circuit comprises a detector element with signal-dependent output current, a load resistance and an operational amplifier. A terminal of the detector element and the load resistance are electrically connected to an input of the operational amplifier. The load resistance is provided in the form of at least two series-connected part-resistors. A compensation capacitor is in each case connected in parallel with each part-resistor, or a number of series-connected part-compensation capacitors are connected in parallel with each part-resistor. The output of the operational amplifier is connected to two of the compensation capacitors or part-compensation capacitors by a feed capacitor so that the effect of a parasitic capacitance of the load resistance is at least partially compensated for.
    Type: Application
    Filed: March 23, 2011
    Publication date: December 27, 2012
    Inventor: Ernst Rau
  • Patent number: 7646247
    Abstract: A frequency compensated operational amplifier includes: an input stage, for receiving an input signal; an output stage, coupled to the input stage, for generating an output signal according to an output of the input stage; a first current source, for providing a first bias current; a second current source, for providing a second bias current identical to the first bias current; an Ahuja compensation circuit, comprising: a matched transistor pair, coupled to the first current source and the second current source; a capacitor coupled between the matched transistor pair and the output stage; and a transconductance boosting circuit, coupled to the matched transistor pair, for boosting transconductance of the matched transistor pair.
    Type: Grant
    Filed: June 2, 2008
    Date of Patent: January 12, 2010
    Assignee: MediaTek Singapore Pte Ltd.
    Inventor: Uday Dasgupta
  • Patent number: 7142059
    Abstract: The invention provides an amplifier arrangement which is of multistage design. The output transistor in the output stage has a coupling path between its control input and its controlled path. The coupling path comprises a series circuit comprising a Miller compensation capacitance and a resistance with a controllable resistance value. It is thus possible to ensure stable operation of the amplifier regardless of bias and load conditions while simultaneously reducing the quiescent current drawn.
    Type: Grant
    Filed: September 27, 2004
    Date of Patent: November 28, 2006
    Assignee: Infineon Technology AG
    Inventors: Axel Klein, Ralf-Rainer Schledz, Marcin Augustyniak
  • Patent number: 6879215
    Abstract: Synthetic circuit elements and amplifier applications for synthetic circuit elements are provided. The synthetic circuit elements disclosed herein may be configured to compensate for some or all of the parasitic capacitance normally associated with circuit elements disposed on a substrate providing a selectable impedance characteristic. Amplifier circuit constructed using such synthetic circuit elements exhibit improved performance characteristics such as improved recovery time, frequency response, and time domain response.
    Type: Grant
    Filed: May 10, 2002
    Date of Patent: April 12, 2005
    Assignee: Linear Technology Corporation
    Inventor: Steven D. Roach
  • Patent number: 5877654
    Abstract: A class A driver circuit (30) has an output stage with a plurality of selectable current sources (42). The selectable current sources (42) are used to optimize the drive capability of the output stage of the class A driver circuit (30) for different applications having different output impedance. In one embodiment, the selectable current sources (42) may be selectable, or switchable, using software programmed by a user. In another embodiment, the current sources may be automatically selected, based on sensing the output current provided to a resistive load. Also, in yet another embodiment, the selectable current sources (42) may be selectable based on the input signal of a first stage amplifier (32). A Miller compensation network (40) includes digitally controlled, switchable capacitors (129) and resistors (128), and provides the necessary amount of Miller compensation for the selected current sources.
    Type: Grant
    Filed: December 2, 1996
    Date of Patent: March 2, 1999
    Assignee: Motorola Inc.
    Inventors: Joseph Yves Chan Yan Fong, Mathew A. Rybicki
  • Patent number: 5729176
    Abstract: A linear differential gain stage (31) has a first input (32), a second input (33), a first output (34), and a second output (35). A differential input voltage is coupled to an input differential transistor pair (39,40). Voltage compensation circuits (53,54) cancel non-linearities due to the input differential transistor pair (39,40). Parasitic capacitance of the input differential transistor pair (39,40) couple current to the first and second inputs (32,33) due to voltage transitions at the first and second outputs (34,35). The current to the first and second inputs (32,33) is canceled by impedance compensation circuits (55,56) that provide an equal magnitude but opposite sign current. The result is an almost infinite input impedance to the linear differential gain stage (31).
    Type: Grant
    Filed: May 3, 1996
    Date of Patent: March 17, 1998
    Assignee: Motorola, Inc.
    Inventors: William Eric Main, Jeffrey C. Durec
  • Patent number: 5392001
    Abstract: A capacitively-coupled amplifier circuit includes an amplifier for receiving an input signal via a coupling capacitance and for amplifying the input signal to produce an output signal. A resistor provides a bias voltage to the amplifier. The resistor is bootstrapped using positive feedback with a loop gain of slightly less than one. The bootstrapping causes an increase in the value of the resistor to lower the cut-in (pole) frequency of the amplifier. The bootstrapping or feedback circuit includes a roll-off (pole) at a frequency below the roll-off (pole) frequency of the amplifier. This prevents phase shift in the feedback loop from adversely effecting the high frequency response of the amplifier. The resulting amplifier circuit exhibits a wide passband and excellent low frequency response despite having a capacitively coupled input signal.
    Type: Grant
    Filed: February 28, 1994
    Date of Patent: February 21, 1995
    Assignee: Hewlett-Packard Company
    Inventors: Thomas F. Uhling, John M. Heumann, Ronald J. Peiffer
  • Patent number: 4910476
    Abstract: High frequency amplifiers require neutrodyning to prevent the risks of self-oscillation generated by the existence of stray capacitances among the electrodes of the active component used in the amplifier. Grid tube amplifiers (such as triodes, tetrodes, pentodes etc.) are more particularly concerned. Instead of simply providing a variable inductive element, in parallel, on the stray capacitance between the input electrode and the output electrode, there is provided a star connection of three reactances between the input electrode, the output electrode and the reference electrode. Only the first reactance is variable. The others are fixed and are in a constant ratio independent of the frequency. Preferably, the variable reactance element is an inductive element, and the other two are capacitive elements. Thus, by means of this single, variable reactance element, it is possible to make a setting, at the same time, of the input or output frequency tuning of the amplifier and of the neutrodyning.
    Type: Grant
    Filed: October 14, 1988
    Date of Patent: March 20, 1990
    Assignee: Thomson-CSF
    Inventors: Michel Benoit, Guy Peillex-Delphe
  • Patent number: 4904951
    Abstract: A technique for reducing phase shift of a signal passing through a large thin film resistor on an insulating layer includes applying a signal to one terminal of the thin film resistor and also to one end of an underlying doped epitaxial region. The opposite terminal of the thin film resistor is connected to a virtual ground or virtual reference voltage produced by an inverting input of an operational amplifier. The corresponding opposite end of the epitaxial layer is connected to ground or other reference voltage. The voltage gradients produced by currents flowing through both the thin film resistor and the epitaxial layer are equal, so that substantially no incremental charging current flows through capacitance between the thin film resistor and the epitaxial layer. Phase shift of the signal flowing through the thin film resistor is thereby avoided.
    Type: Grant
    Filed: June 6, 1988
    Date of Patent: February 27, 1990
    Assignee: Burr-Brown Corporation
    Inventors: Johnnie F. Molina, Robert M. Stitt, II
  • Patent number: 4751471
    Abstract: An amplifying circuit for amplifying a bipotential input signal, including an insulating housing having a conductive input contact mounted on the housing and adapted to engage a human body so that the bipotential input signal applied to the contact; a lead amplifier having inverting and non-inverting inputs, one of which is coupled to the input contact, and an output; first and second diodes connected in parallel inverse polarity across the inputs of the lead amplifier; third and fourth diodes connected in parallel inverse polarity from the inverting input of the lead amplifier to a circuit common potential; and an output resistor connected from the inverting input to the output of the lead amplifier. Portions of the input contact are surrounded by a voltage drive shield connected to the output of the lead amplifier.
    Type: Grant
    Filed: December 23, 1986
    Date of Patent: June 14, 1988
    Assignee: Spring Creek Institute, Inc.
    Inventor: W. J. Ross Dunseath, Jr.
  • Patent number: 4588959
    Abstract: A method and hum neutralization circuit for a grounded grid triode radio frequency amplifier in which the hum signal is detected and a portion thereof related to the amplification of the amplifier applied to the cathode to oppose, when amplified, in amplitude and phase, the effects of the hum signal on the output signal of the amplifier.
    Type: Grant
    Filed: July 12, 1984
    Date of Patent: May 13, 1986
    Assignee: Harris Corporation
    Inventors: William E. Herzog, John H. Atkins
  • Patent number: 4246542
    Abstract: A second order section of an electronic filter comprises three cascaded amplifier stages and a compensating amplifier stage coupled between the first and second amplifier stages. The compensating stage introduces a leading phase shift at high frequencies so that the normalized transfer function of the circuit, for different frequencies, is substantially identical.
    Type: Grant
    Filed: May 8, 1979
    Date of Patent: January 20, 1981
    Assignee: Rockland Systems Corporation
    Inventor: S. N. Thanos