Korkmaz, Muhammet Oguz; Babacan, Yunus; Yesil, Abdullah

In this paper, two floating memcapacitor emulator circuits, one based on a second-generation current conveyor (CCII) and the other on an operational transconductance amplifier (OTA), are proposed. The first floating memcapacitor contains a single CCII, one multiplier, and four transistors, while the second one comprises a single OTA, one multiplier, and only two transistors. External transistors are operated as electronically controllable grounded capacitors and resistors. Therefore, the inverse memcapacitances of the circuits are adjusted electronically by applying appropriate bias voltages. Both emulator circuits can be operated to have incremental or decremental characteristics. The analyses of frequency response, electronic adjustability, temperature behavior, and non-volatile behavior of the circuits, as well as Monte Carlo analysis, are performed. Furthermore, an adaptive learning circuit is utilized to demonstrate the applicability of the proposed memcapacitor. Additionally, the CCII-based emulator circuit is constructed on a printed circuit board using discrete circuit elements and tested experimentally. The non-volatility feature of the circuit was tested for both incremental and decremental memcapacitors. The simulation and experimental results agree with the expected results.

Gur, Muslum; Akar, Funda; Orman, Kamil; Babacan, Yunus; Yesil, Abdullah; Gul, Fatih

Memcapacitor is a type of capacitor but exhibits nonlinear behavior, and its capacitance depends on the past capacitance value. Researchers focused on the memcapacitors and meminductors upon postulation of memristor which is the forth passive fundamental circuit element. Memcapacitor emulator circuits have continuously been designed by researchers since it cannot be found as discrete circuit elements. A number of memcapacitor emulators have been offered in the literature to investigate its usability in CMOS designs. However, the offered designs have some insufficiencies such as grounded restriction, being composed of complex structure, etc. In this study, we designed a simple multioutput operational transconductance amplifier (MO-OTA)-based fully floating and electronically controllable memcapacitor emulator circuit. The circuit is composed of only two MO-OTAs, two analog multipliers, two grounded passive elements, and four transistors. This proposed circuit can also be implemented in VLSI and on breadboard using discrete circuit elements. Performance analyses were completed via using TSMC 0.18 μm parameters. Finally, the obtained results of the proposed fully floating emulator circuit are consistent with the expected memcapacitors behavior. This makes the circuit suitable for ideal memcapacitor emulator.