Käänteisvastus

Käänteisvastus, often translated as negative resistance, is a property of certain electronic components or circuits where an increase in voltage across the component leads to a decrease in current through it, or vice versa. This behavior is contrary to that of a standard resistor, where current increases proportionally with voltage according to Ohm's Law.

Negative resistance is not a fundamental property of passive components like resistors, capacitors, or inductors. Instead, it arises from the active mechanisms within devices that utilize power to achieve this effect. Examples of devices that exhibit negative resistance include tunnel diodes, Gunn diodes, and arc lamps. These devices typically have a region in their current-voltage characteristic curve where the slope is negative.

The concept of negative resistance is crucial in the design of oscillators, amplifiers, and other electronic circuits that require regenerative feedback. By incorporating a negative resistance element, it's possible to overcome resistive losses within a circuit and sustain oscillations or achieve signal amplification. However, the inherent instability associated with negative resistance requires careful circuit design to ensure predictable and stable operation. When used, negative resistance elements are often biased to operate within their negative resistance region.