Abstract: A memristor-based emulator including a memristor circuit for use in digital modulation that includes a first current feedback operational amplifier (CFOA) having multiple terminals in communication with a capacitor Cd and in further communication with a resistor Ri. A second CFOA having multiple terminals is in communication with the first CFOA and is adapted to be in further communication with a voltage vM to provide an input current iM for integration by a capacitor Ci. A nonlinear resistor is in communication with the second CFOA. A third CFOA having multiple terminals is in communication with the nonlinear resistor and is in further communication with the first CFOA and a resistor Rd. 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 ON and OFF values of a resistance of a realized memristor.

Abstract: An apparatus for a direct down-conversion of modulated RF signals, the device including: a first power detector connected between an input port for the modulated RF signal and ground, which outputs a first DC signal, a second power detector connected between an input port for a local oscillator signal and ground, which outputs a second DC signal, the local oscillator signal having the same center frequency as the modulated RF signal, and a third power detector connected between the input port for the modulated RF signal and the input port for the local oscillator signal, which outputs a third DC signal.

Abstract: A resonant tunneling diode or diode array oscillator (10) including a resonant diode (11) is coupled to a millimeter-wave source (14) and a quench generator (16) for periodically quenching the oscillations so that the average oscillation time of the oscillator is proportional to signal strength of the source (14). The signal source can be from an antenna such as a dipole or tapered slot line antenna.

Abstract: Systems and methods are provided for calibration of a transmitter system modulator, wherein local oscillator nodes of a mixer are held at first and second voltages, and a first offset value is determined. The terminals are then held at third and fourth voltages and a second offset value is determined. The first and second offset values are then averaged to provide a calibration offset value for the modulator.

Abstract: An optoelectronic phase locked loop for clock recovery in high-speed optical time division multiplexed systems. The optoelectronic phase locked loop includes a balanced photodetector through which the polarity ambiguity in error signal is resolved and the cancellation of laser noise enabling clock recovery with low timing jitter. The optoelectronic phase locked loop also includes an electroabsorption modulator as a phase detector, a lowpass filter, a variable controlled oscillator, a power divider and an amplifer.