The memristor is a non-linear circuit element. In principle one can imagine an infinite variety of non-linear elements with different types of non-linearity.
Resistors, capacitors, and inductors are linear elements. Linear elements must have response consisting of current in-phase with voltage or ±90° out-of-phase, or some linear combination. That leaves only three possibilities. You might imagine a fourth possibility, with current 180° out-of-phase, but that would dump energy into the circuit instead of dissipating it. In thermal equilibrium, that would violate thermodynamics. So, at least at any one frequency, resistors, capaciitors, and inductors are all you need.
Mike W.
(published on 07/10/2017)
