Negative resistance devices

Two‐terminal devices which exhibit a type‐S (current‐controlled) or type‐N (voltage‐controlled) negative differential resistance can be built using only two bipolar transistors and linear positive resistors without any internal biasing power supply. Two general algorithms are presented in this paper for systematically generating all such devices. Hundreds of negative resistance devices have been derived to date using these algorithms and a selection of these circuits is presented in this paper along with their computer‐simulated v‐i curves. Laboratory measurements of a few sample circuits agree remarkably well with the computer‐simulated results.