A negative resistance converter (NRC) is a two-terminal active circuit whose terminal current/voltage (i/v) relationship is that of a negative resistor. NRCs with a nonlinear i/v relationship are especially useful for creating marginal oscillators (MO) by canceling the losses in a tuned circuit. Though NRCs have been implemented in earlier MO designs, few authors have fully understood what the shape of an NRC's i/v characteristic should be, and none have presented simulated or experimental verification of their NRC's i/v characteristic. This thesis examines three previous NRC implementations both analytically and through the use of simulation software. This thesis goes on to design and synthesize an analog nonlinear NRC using high-frequency operational amplifiers and Schottky diodes. The NRC is designed such that its i/v characteristic can be tuned with potentiometers. Finally, this thesis experimentally confirms that the NRC's i/v characteristic matches that of a desired characteristic characteristic.
