A versatile design giving both N-type and S-type of negative-resistances

Abstract

There is no network design in the literature so far which can yield both voltage controlled and current controlled negative-resistances with a simple circuit modification. This has greatly restricted the applicability of negative-resistances in active network designs because of the possibility of the system becoming unstable if the impedance of the source driving the negative-resistance circuit is not properly matched to the value of negative-resistance. In this paper, we give a design using two transistors and four resistances, which can be used as either a voltage controlled or a current controlled negative-resistance, given the flexibility of changing one transistor. Both the circuits are individually versatile and it should be possible to integrate the design in microelectronic forms.