Negative impedance converter

About: Negative impedance converter is a research topic. Over the lifetime, 5801 publications have been published within this topic receiving 87636 citations.

DC-DC converter having magnetic feedback

Abstract: A DC-DC converter suitable for multiple converter circuit topologies is disclosed. The DC-DC converter utilizes magnetic feedback of the output load current to provide broad inductance control of a magnetic element, while inhibiting saturation of the switched winding or windings of the magnetic element.

Compact models of negative-capacitance FinFETs: Lumped and distributed charge models

Abstract: This work presents insights into the device physics and behaviors of ferroelectric based negative capacitance FinFETs (NC-FinFETs) by proposing lumped and distributed compact models for its simulation. NC-FinFET may have a floating metal between ferroelectric (FE) and the dielectric layers and the lumped charge model represents such a device. For a NC-FinFET without a floating metal, the distributed charge model should be used and at each point in the channel the ferroelectric layer will impact the local channel charge. This distributed effect has important implications on device characteristics as shown in this paper. The proposed compact models have been implemented in circuit simulators for exploring circuits based on NC-FinFET technology.

Low-frequency admittance of quantized Hall conductors.

Abstract: We present a current and charge conserving theory for the low-frequency admittance of a two-dimensional electron gas connected to ideal metallic contacts and subject to a quantizing magnetic field. In the framework of the edge-channel picture, we calculate the admittance up to first order with respect to frequency. The transport coefficients in first order with respect to frequency, which are called emittances, determine the charge emitted into a contact of the sample or a gate in response to an oscillating voltage applied to a contact of the sample or a nearby gate. The emittances depend on the potential distribution inside the sample, which is established in response to the oscillation of the potential at a contact. We show that the emittances can be related to the elements of an electrochemical capacitance matrix, which describes a (fictitious) geometry in which each edge channel is coupled to its own reservoir. The particular relation of the emittance matrix to this electrochemical capacitance matrix depends strongly on the topology of the edge channels: We show that edge channels that connect different reservoirs contribute with a negative capacitance to the emittance. For example, while the emittance of a two-terminal Corbino disk is a capacitance, the emittance of a two-terminal quantum Hall bar is a negative capacitance. The geometry of the edge-channel arrangement in a many-terminal setup is reflected by symmetry properties of the emittance matrix. We investigate the effect of voltage probes and calculate the longitudinal and the Hall resistances of an ideal four-terminal Hall bar for low frequencies. \textcopyright{} 1996 The American Physical Society.

Temperature compensated constant-voltage circuit and temperature compensated constant-current circuit

Abstract: A constant-voltage circuit which can be driven by a low voltage (lower than 1 V) of a nickel-cadmium battery, etc., and which provides a temperature-compensated stable voltage output. The constant-voltage circuit comprises battery 1, band-gap-type current-mirror-type constant-current source circuit 3 which outputs collector current I C9 of transistor Q 9 with a positive temperature coefficient, current source circuit 5 which outputs collector current I C8 of transistor Q 8 having a negative temperature coefficient and defined by base-emitter voltage V BEQ7 of transistor Q 7 , and a load resistor element R 0 . At node N 0 , collector current I C9 and collector current I C8 are added. The temperature coefficients of these two currents cancel each other. Consequently, the current at node N 0 does not have temperature dependence. Load resistor element R 0 converts this current to a voltage as the output voltage V OUT .

Circuit apparatus for transformerless conversion of an electric direct voltage into an alternating voltage

Abstract: In a circuit apparatus for transformerless conversion of an electric direct voltage of a two-pole direct voltage source ( 1 ) connected to ground having a first voltage pole (+) and a second voltage pole (−) into an alternating voltage, hazardous capacitive leakage currents are avoided by connecting the direct voltage source ( 1 ) to ground and the DC-AC converter ( 400 ) is operated at a controlled intermediate circuit voltage, a DC-DC converter stage ( 300 ) being connected between the direct voltage source ( 1 ) and the DC-AC converter ( 400 ), said DC-DC converter stage providing at its output a +/− voltage that is symmetrical with respect to the grounding point, two series-connected capacitors ( 41, 42 ) having the same polarity and being connected to ground at their connecting point (V) and controlled are charged by two buck-boost choppers ( 100, 200 ) connected one behind the other.