Negative Resistance

Negative resistance is a property of some electric circuits where an increase in the current entering a port results in a decreased voltage across the same port. This is in contrast to a simple ohmic resistor, which exhibits an increase in voltage under the same conditions. Negative resistors are theoretical and do not exist as a discrete component. However, some types of diodes (e.g., tunnel diodes) can be built that exhibit negative resistance in some part of their operating range. Such a differential negative resistance is illustrated in Figure 1 with a resonant-tunneling diode. Electric discharges through gases exhibit negative resistance, and some chalcogenide glasses, organic semiconductors, and conductive polymers exhibit a similar region of negative resistance as a bulk property. In electronics, negative resistance devices are used to make bistable switching circuits, and electronic oscillators, particularly at microwave frequencies



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Other articles related to "negative resistance, negative, resistance":

Negative Resistance - Applications - Impedance Cancellation
... Negative impedances can be used to cancel the effects of positive impedances, for example, by eliminating the internal resistance of a voltage source or making the internal resistance of ...
Negative Differential Conductivity
... Negative resistance is a property of some electric circuits where an increase in the current entering a port results in a decreased voltage across the same port ... Negative resistors are theoretical and do not exist as a discrete component ... tunnel diodes) can be built that exhibit negative resistance in some part of their operating range ...
Vacuum Tube - History and Development - Tetrodes and Pentodes
... This is the so-called "tetrode kink" and is an example of negative resistance which can itself cause instability ... The otherwise undesirable negative resistance was exploited to produce an extremely simple oscillator circuit only requiring connection of the plate to a resonant LC circuit to oscillate this was ... The so-called dynatron oscillator thus operated on the same principle of negative resistance as the tunnel diode oscillator many years later ...
Ridley–Watkins–Hilsum Theory
... theory (RWH) explains the mechanism by which differential negative resistance is developed in a bulk solid state semiconductor material when a voltage is applied to the terminals of the sample ... Negative resistance oscillations in bulk semiconductors had been observed in the laboratory by J ... While this transfer occurs, the material exhibits a decrease in current – that is, a negative differential resistance ...
Negative Differential Conductivity - Applications - Amplifiers
... A device exhibiting negative resistance can be used to amplify a signal and this is an especially useful technique at microwave frequencies ... Such devices do not present as pure negative resistance at these frequencies (in the case of the tunnel diode a large parallel capacitance is also present) and a matching filter is usually required ... so the circuit can be represented as a pure resistance followed by a bandpass filter ...

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