Concept Of Negative Resistance Research Articles

Fractional circuit network theory with n-V-structure

This paper studies a class of circuit network model with fractional n-V-structure, the model contains several independent resistance elements, so it is the topology of multiple network models. First, this paper calculates the equivalent resistance of n-V circuit network by constructing equivalent model, and gives two closed equivalent resistance analytic expressions. Additionally, the concept of negative resistance is put forward. A series of special results of equivalent resistance are discussed. Finally, the complex impedance characteristics of fractional n-V structure circuit networks are studied in detail by using variable substitution technique. The amplitude frequency characteristics and phase frequency characteristics of fractional n-V structure circuit network are revealed through Matlab drawing research.

Prikaz negativne otpornosti realizovane pomoću konvertora negativne impedanse

In this paper, we presented the concept of negative resistance in a simplified way. Although the negative resistance was noticed even in the 19th century, it still causes inconveniences due to its absence as a discrete component. In this paper, the negative resistance was realized using a negative impedance converter. To understand clearly its influence in the electric circuit, a voltage divider circuit was used, which was analyzed both numerically and symbolically. The numerical analysis was performed in the simulation program LTspice, while the symbolic analysis was conducted in the Wolfram Mathematica software package. First, a voltage difference circuit with a positive resistor value was analyzed, after that one of the resistors was replaced with a negative resistance resistor. Additionally, simulations for the positive and negative equivalent resistance of the circuits were performed. Finally, the practical realization of the voltage divider circuit was demonstrated in order to make this concept more complete.

Формирование понятия отрицательного сопротивления в курсе общей физики технических вузов

Формирование понятия отрицательного сопротивления в курсе общей физики технических вузов

Resistance formulae of a multipurpose n‐step network and its application in LC network

SummaryWe consider a multipurpose n‐step network with cross resistors that is a profound problem that has not been resolved before. This network contains a number of different types of resistor network model. This problem is resolved by three steps: First of all, we simplify a complex graphics into a simple equivalent model; next, we use Kirchhoff's laws to analyse the network and establish a nonlinear difference equation; and finally, we construct the method of equivalent transformation to obtain the general solution of the nonlinear difference equation. In this paper, we created a new concept of negative resistance for the needs of the equivalent conversion and obtain two general resistance formulae of a multipurpose ladder network of cross resistors. As applications, several interesting specific results are produced. In particular, an n‐step impedance LC network is discussed. Our method and the results are suitable for the research of complex impedance network as well. Copyright © 2017 John Wiley & Sons, Ltd.

Nyquist-Stability-Criterion-Based SSR Explanation for Type-3 Wind Generators

Type-3 wind generators in series-compensated networks could lead to subsynchronous resonance (SSR) oscillations- a phenomenon observed recently. In this letter, impedance-based Nyquist stability criterion is applied to explain the phenomenon. The resonance is not due to the shaft's torsional characteristics, but rather due to its slip related impedance, which can give rise to equivalent negative resistance. The explanation corroborates the authors' previous explanation of self-excitation using net negative resistance concept. Nyquist map is also able to demonstrate the impact of wind speed on SSR.

On the Amplitude Analysis of MOS Differential LC Oscillators

In this paper we discuss the application of the negative resistance concept to estimate the amplitude of oscillation of MOS differential LC oscillators in a steady-state regime. This is done by approximating the large-signal non-linearity, associated with the negative resistance, by a piecewise linear model. The analytical findings are in very good agreement with the results provided by transient circuit simulation.

A compact and low-phase-noise Ka-band pHEMT-based VCO

A low phase-noise Ka-band monolithic voltage-controlled oscillator (VCO) designed using the negative resistance concept is reported. A circuit fabricated using the three-dimensional monolithic microwave integrated circuit technology exhibits a high integration level; its size is a record at just 0.5 mm/sup 2/. On-wafer measurements demonstrate a low phase noise of -102 dBc/Hz at a 1-MHz offset. The VCO delivers an output power of 11.8 dBm at the center frequency of 28.3 GHz. The frequency tuning range is more than 3.8 GHz. Dependence of the circuit performance on the bias conditions is also reported and suggests that an optimum phase-noise characteristic can be achieved when biasing the transistor to optimize its transconductance and noise figure.

An Intuitive Method for Oscillator Analysis Using Miller's Theorems

In this paper we discuss an intuitive method for the calculation of the oscillation frequency and the calculation of the conditions for sustained oscillation of analogue oscillators using the concept of negative resistance combined with Miller's theorems.

An analytic method of microwave bipolar single‐frequency and voltage‐controlled oscillator design

An analytic method of microwave bipolar oscillator design, allowing one to define explicit expressions for optimum values of feedback elements and load through bipolar transistor Z-parameters, is developed. A negative resistance concept is utilized to design series feedback microwave bipolar oscillator with optimized feedback elements and maximum output power in terms of the transistor impedance parameters. The design of the wideband common-base bipolar voltage controlled oscillators (VCOs) is also presented. Numerical and experimental results verify the validity of the design methods described. ©1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 403–414, 1999.

An analytic method of microwave transistor oscillator design

An analytic method of microwave transistor oscillator design is developed, allowing one to define explicit expressions for optimum values of feedback elements and load through immitance parameters of the active two-port network. A negative resistance concept is used to design a series feedback microwave GaAs FET oscillator with optimized feedback elements and maximum output power in terms of the transistor impedance parameters. A large-signal model for GaAs FET is derived, based on its small-signal Z parameters and DC characteristics. Numerical results verify the validity of the design method.

Negative resistance design for crystal oscillators

An analytic method using the concept of negative resistance is developed for the design of microwave crystal oscillators. A systematic design procedure is proposed which with minor modifications can be applied to other oscillators, such as voltage controlled oscillators. The design procedure is applied to the design of a crystal oscillator having a fundamental frequency in the microwave range. The design is verified experimentally and compared with CAD results.

The Negative Resistance Concept in Modern Electronics†

ABSTRACT The importance of negative resistance as an equivalent circuit element for the description of power producing devices has been the subject of many papers since the early 1930's. The present paper surveys the subject with particular reference to some of the more modern high frequency valves Negative resistance devices can be divided into two main classes according to whether they are current controlled or voltage controlled and the properties of each class are enumerated and contrasted. The general stability criterion for a.c. circuits containing negative resistance is examined and the use of negative resistance for amplifiers and oscillators, both in the transient and steady states, is discussed. Negative resistance can be produced in many circuits by the addition of positive feedback, although there are many other basic types of device in which the negative resistance property is intrinsic. These latter are classified and numerous illustrations are given. In conclusion the description of microwa...

Negative Resistance

Relaxation oscillations and other discontinuous phenomena in nature are considered in terms of the regenerative feedback needed for their appearance. In the electrical case the concept of negative resistance is often especially convenient and the present paper attempts to summarize and discuss this, as well as to present a novel current vs voltage characteristic of more complicated form. Some counting devices, impulse propagators, and several nonstationary systems are mentioned and there are explanations in terms of analogous nonelectrical systems.