Design and Analysis of Mem-elements Emulator using Analog Building Blocks

Abstract

The evolution of electronic components has led to the discovery of various mem-elements, including memristors, memcapacitors, and meminductors, which exhibit memory-dependent behavior. These elements are poised to revolutionize many fields of science and engineering. However, fabricating these devices at the nanoscale remains a significant challenge, thereby creating a demand for mem-element emulators to facilitate experimental research and circuit design. Earlier, electronic systems relied on fundamental components like resistors, capacitors, and inductors alongside semiconductor devices. Even while these conventional components are essential, they are not very flexible in responding to changing environmental conditions. Mem-elements overcome these limitations and potentially revolutionize the industry by enhancing circuit design, functionality, and efficiency. Therefore, researchers and practicing engineers use emulation techniques to replicate mem-element functionality, allowing engineers to study their behavior without needing physical prototypes. This thesis presents the development of a versatile mem-element emulator capable of reproducing mem-elements’ behavior, including memristors and meminductors. This work lays the groundwork for further exploration of mem-elements in future electronic systems and provides a platform for simulating their diverse functionalities. In the thesis, six designs of mem-element emulators have been presented, including three for memristors and another three for meminductors. These circuits utilize analog building blocks such as operational transconductance amplifiers (OTAs), current differencing buffered amplifiers (CDBAs), voltage differencing gain amplifiers (VDGAs), fully-balanced voltage differencing buffered amplifiers (FB-VDBAs), and voltage differencing transconductance amplifiers (VDTAs). The first memristor emulator is designed using OTA and CDBA. The second memristor emulator employs VDGA, whereas the third memristor emulator is designed using FB-VDBA. These designs feature a grounded capacitor as a memory element and achieve grounded and floating configurations with incremental and decremental topologies. In addition, the first meminductor emulator is designed using two OTAs. The second meminductor emulator has been designed using VDGA, while the third meminductor emulator is designed using a VDTA. In all designs of meminductor emulators, CDBA has been utilized to obtain incremental and decremental topologies. One of the capacitors is used as a memory element, while the other is used to form the inductance. The emulator’s performance is thoroughly analyzed through pinched hysteresis loops, non- volatility tests, temperature analyses, Monte Carlo analyses, etc. These analyses confirm the efficacy of proposed emulator designs in natural environments. The emulators also offer the feature of electronic tunability, often required to adjust the internal parameters of the circuit. These emulators display pinched hysteresis loops across a broad frequency range (hundreds of Hz to MHz). Both memristor and meminductor emulators present promising results that offer a wide range of memristances and meminductances. The memristor emulators have been used in the design of analog filters, while meminductor emulators are used in adaptive learning and chaotic circuits, demonstrating satisfactory performance. Non-ideal analyses have also been conducted to verify their performance in the natural environment. The simulation results have been obtained using Eldo simulation tools for 180 nm CMOS technology parameters.