Hi,

I have read about what is negative resistance all about in wikipedia. It doesn't exists in real components. It can be synthesized using op-amp (as what I have read in wikipedia):

http://en.wikipedia.org/wiki/Negative_resistance

How can a negative resistance effect a circuit in real application? Anyone has tried on a real hardware?

Regards,
lkgan

 

I simulated it in this: http://www.falstad.com/afilter;

Interestingly, it seems the response is identical frequency wise, but the phase response is reversed.

 

Actually negative resistance not only exists, but is very common. Neon bulbs, tunnel diodes, and many more devices have regions of negative resistance in their characteristic curves. It is the principle behind a relaxation oscillator.