Memristor-based emulator for use in digital modulation

A memristor-based emulator for use in digital modulation including a memristor circuit, the memristor circuit comprising:

• a first current feedback operational amplifier (CFOA), the first CFOA having a w-terminal, an x-terminal, a y-terminal, and a z-terminal, the first CFOA in communication with a capacitor Cd at the x-terminal of the first CFOA and in further communication with a resistor Ri at the z-terminal of the first CFOA;
• a second CFOA, the second CFOA having a w-terminal, an x-terminal, a y-terminal, and a z-terminal, the y terminal of the second CFOA in communication with the w-terminal of the first CFOA, the x-terminal of the second CFOA adapted to be in communication with a voltage vM to provide an input current iM that is integrated by a capacitor Ci;
• a nonlinear resistor including a first resistor R1 and second resistor R2 and a diode D, the nonlinear resistor in communication with the second CFOA at the w-terminal of the second CFOA;
• and
• a third CFOA, the third CFOA having a w-terminal, an x-terminal, a y-terminal, and a z-terminal, the third CFOA in communication with the nonlinear resistor through the x-terminal of the third CFOA, the w-terminal of the third CFOA in communication with the y-terminal of the first CFOA, the z-terminal of the third CFOA in communication with a resistor Rd, wherein the third CFOA and the resistor Rd act as an inverting amplifier associated with the nonlinear resistor to increase a current gain to increase a difference between an ON value of a resistance and an OFF value of resistance of a memristor realized by the memristor circuit.

A memristor-based emulator for use in digital modulation including a memristor circuit, the memristor circuit comprising:

• a first current feedback operational amplifier (CFOA), the first CFOA having a w-terminal, an x-terminal, a y-terminal, and a z-terminal, the first CFOA in communication with a capacitor Cd at the x-terminal of the first CFOA and in further communication with a resistor Ri, at the z-terminal of the first CFOA;
• a second CFOA, the second CFOA having a w-terminal, an x-terminal, a y-terminal, and a z-terminal, the y terminal of the second CFOA in communication with the w-terminal of the first CFOA, the x-terminal of the second CFOA adapted to be in communication with a voltage vM to provide an input current iM that is integrated by a capacitor Ci;
• a nonlinear resistor including a first resistor R1 and second resistor R2 in a parallel relationship and further including a germanium diode D, the nonlinear resistor in communication with the second CFOA at the w-terminal of the second CFOA;
• and
• a third CFOA, the third CFOA having a w-terminal, an x-terminal, a y-terminal, and a z-terminal, the third CFOA in communication with the nonlinear resistor through the x-terminal of the third CFOA, the w-terminal of the third CFOA in communication with the y-terminal of the first CFOA, the z-terminal of the third CFOA in communication with a resistor Rd,
• wherein the third CFOA and the resistor Rd act as an inverting amplifier associated with the nonlinear resistor to increase a current gain to increase a difference between an ON value of a resistance and an OFF value of resistance of a memristor realized by the memristor circuit, and
• wherein the memristor-based emulator is adapted to be driven by a current.