What is the significance of Negative Capacitance.?

Question

For example, IN BJT CB configuration, the interelectrode capacitance, when reflected back at the input by its miller equivalent, behaves as a negative capacitance. What is the meaning.

Answer 1

You can get a negative impedance effect when an impedance is bridged by a non-inverting gain circuit. Effectively, energy is pumped back into the driving potential. See http://en.wikipedia.org/wiki/Negative_impedance_converter

Answer 2

In single phase ac circuits there may not be any significance. In dc circuits where more than one Voltage or current source is used in a single circuit using negative values of Voltage and current enable you to calculate net amplitude values of Voltage and current throughout the circuit.. The polarity (positive or negative) of a Voltage source across a semiconductor junction determines whether or not current will flow through the junction therefore observance of the polarity of Voltage and current become very significant in electronic circuits.