j multiplier: a new network device

This letter describes a novel linear nonreciprocal active 2-port network element called a j multiplier. It has the unique property that, whenever a nonlinear immittance is connected across one of its ports (port 1), the resulting 2-terminal network behaves as the original immittance multiplied by j; i.e. a resistance appears as an imaginary resistance, whereas capacitors or inductors appear as frequency-dependent real resistances. There are two types of j multipliers: the voltage j multiplier and the current j multiplier. The realisations of both these types of devices at any frequency using ±jR elements, or at one single frequency using ±R, L and C elements and a controlled source, are given.