Fuzzy and multiple valued logic circuit applications using resonant tunneling diodes

The Resonant Tunneling Diode (RTD) possesses unique electrical characteristics which make it suitable for multiple valued logic (MVL), memory and other signal processing applications. It is known as the fastest all-electronic switch at room temperature. In this dissertation, several new circuits based on the Resonant Tunneling Diode (RTD)--a quantum effect device, are presented.; First, for fuzzy logic applications, the method used is to realize a multi-label membership function with a single sawtooth type RTD for fuzzification and defuzzification. The multi-peaked RTD I-V characteristics can be generally classified as triangular, sawtooth and hysteretic types. These different types of I-V characteristics can be utilized to construct membership functions for both fuzzifiers and defuzzifiers. RTDs can also be used to construct some of the basic building blocks within the proposed fuzzy logic hardware. In addition to the reduced circuit complexity, the speed of operation should also be enhanced compared to the previously proposed fuzzy logic circuits using conventional devices such as CMOS or TTL.; Next, a possible solution for the future generations of memory device is presented. The memory cells consist of a series of vertically integrated RTDs where the only means of "writing" is through the topmost RTD contact. SPICE Simulation and breadboard experiments confirm the operation of the "write" operation. The "read" scheme is also proposed. The resulting memory cells can be used to construct future generations of 3 dimensional storage and computing devices.; Finally, because logic implementation is such an important issue in computer design, RTDs can be utilized for constructing and optimizing many other types of analog and multi-valued digital applications in order to save chip area and improve speed. Some examples are Multiplexer, Demultiplexer and Programmable Logic circuits, etc. For the above circuit applications, an universal literal gate is an extremely important functional block in any radix. This dissertation presents the basic operation of a current/voltage mode RTD based literal gate, where its functionality is verified by both simulation and experiment. The simulation result indicates that the RTD based literal gate is far superior than CMOS implementations from both speed and circuit compactness standpoints.