660 results about "Negative resistance" patented technology

A negative resistance device (NRD) has a MOSFET-like structure, and is biased by shorting the gate and source together at a fixed applied potential and applying a different fixed potential to the drain, and sweeping the bulk potential towards the drain potential, causing the bulk current to exhibit a negative resistance characteristic. The NRD may be used in a memory circuit (10) in which a resistor (R) is connected between the bulk (2) and a fixed potential. Two States of the circuit at which the current through the resistor matches that through the bulk of the NRD are stable, providing for bistable memory operation.

This invention provides a voltage controlled oscillator with low phase noise containing a LC resonant loop, a negative resistance generation circuit and a noise suppression loop including a T(or delta) base bias resistant circuit, the said noise suppression loop is for reducing the noise of the said voltage-controlled oscillator and improving its phase noise performance.

The invention discloses a subsynchronous oscillation suppression method for a grid-connected system of a double-feed wind power plant based on virtual resistance, and the method comprises the steps: establishing an impedance model of the double-feed wind power plant according to the operating parameters and control parameters of the double-feed wind power plant and a circuit structure and parameters of the grid-connected system of the double-feed wind power plant; calculating the equivalent negative resistance amplitude of a rotor-side loop, and determining the rotor winding resistance and therotor-side converter equivalent resistance according to the impedance model of the double-feed wind power plant; obtaining a virtual resistance control coefficient according to the rotor winding resistance and the rotor-side converter equivalent resistance, and adjusting the size of the virtual resistance through the virtual resistance control coefficient. The method only needs to adjust the virtual resistance control coefficient to adjust the size of the virtual resistance so as to counteract the rotor winding resistance and the equivalent resistance of the rotor-side converter, and reduce the equivalent negative resistance amplitude of the rotor-side loop, thereby achieving the suppression of the subsynchronous oscillation of a system.

Disclosed are multiphase oscillators comprising a plurality of delay stages serially coupled in a loop by a plurality of nodes, with the loop being folded to provide two concentric rings of delay stages with equal numbers of allocated nodes. A second plurality of negative-resistance elements are provided, each element having a first output coupled to a node on the first concentric ring and a second output coupled to a node on the second concentric ring. Each such output switches between first and second voltage levels, and provides a negative resistance to a signal coupled to it during at least a portion of the transition between voltage levels. The outputs of an element switch to opposite voltage levels. With this construction, a high-voltage pulse propagates around the loop of delay stages, with a low-voltage pulse propagating behind it. Also disclosed are circuits to control the direction of pulse propagation.

An Adjustable Field Effect Rectifier uses aspects of MOSFET structure together with an adjustment pocket or region to result in a device that functions reliably and efficiently at high voltages without significant negative resistance, while also permitting fast recovery and operation at high frequency without large electromagnetic interference.