Abstract: A method of separating a desired signal from an undesired signal includes obtaining a total input signal comprising the desired signal and the undesired signal in a time domain occupying a time duration from time t1 to time t2 of a single symbol in the desired signal. A transform is performed of the total input signal wherein an output of the transform is a time domain signal representing the desired signal.

Abstract: A same-aperture any-frequency simultaneously transmit and receive (STAR) system includes a signal connector having a first port electrically coupled to an antenna, a second port electrically coupled to a transmit signal path, and a third port electrically coupled to receive signal path. The signal connector passes a transmit signal in the transmit signal path to the antenna and a receive signal in the receive signal path. A signal isolator is positioned in the transmit signal path to remove a residual portion of the receive signal from transmit signal path. An output of the signal isolator provides a portion of the transmit signal with the residual portion of the receive signal removed. A signal differencing device having a first input electrically coupled to the output of the signal isolator and a second input electrically coupled to the third port of the signal connector subtracts a portion of the transmit signal in the receive signal path thereby providing a more accurate receive signal.

Abstract: A method of interference suppression with intermodulation distortion mitigation includes processing an RF signal comprising an RF signal of interest and an RF interfering signal to produce a first and second RF drive signal each with a desired RF interference signal power and having a 90 degree relative phase. The first RF drive signal is imposed onto a first optical signal with a modulator to generate a first modulated optical signal so that the modulator has a large-signal behavior that is characterized by a Bessel function of the first kind J1(?), wherein the desired power at a frequency of the interference signal of the first drive signal is chosen to correspond to a zero of the Bessel function of the first kind J1(?).

Abstract: A bi-directional signal interface includes a first and second port configured to pass transmit RF signals and receive RF signals. A MZI includes a first traveling wave electrode connected to the first bidirectional signal port and a second traveling wave electrode connected to the second bidirectional signal port. A coupler has an input connected to a transmit input port, a first output connected to the first traveling wave electrode, and a second output connected to a second end of the second traveling wave electrode. A laser provides an optical signal to the MZI. An optical filter is coupled to an output of the MZI and preserves the optical carrier and the modulation sideband at the second frequency and rejects the modulation sideband at the first frequency. A detector converts light received from the filter to the receive RF signal and a suppressed level of the transmit RF signal.

Abstract: A method of interference suppression with intermodulation distortion mitigation includes processing an RF signal comprising an RF signal of interest and an RF interfering signal to produce a first and second RF drive signal each with a desired RF interference signal power and having a 90 degree relative phase. The first RF drive signal is imposed onto a first optical signal with a modulator to generate a first modulated optical signal so that the modulator has a large-signal behavior that is characterized by a Bessel function of the first kind J1(?), wherein the desired power at a frequency of the interference signal of the first drive signal is chosen to correspond to a zero of the Bessel function of the first kind J1(?).

Abstract: A method of interference suppression with intermodulation distortion mitigation includes processing an RF signal comprising an RF signal of interest and an RF interfering signal to produce a first and second RF drive signal each with a desired RF interference signal power and having a 90 degree relative phase. The first RF drive signal is imposed onto a first optical signal with a modulator to generate a first modulated optical signal so that the modulator has a large-signal behavior that is characterized by a Bessel function of the first kind J1(?), wherein the desired power at a frequency of the interference signal of the first drive signal is chosen to correspond to a zero of the Bessel function of the first kind J1(?).

Abstract: An electromagnetic interface having an impedance with a resistive and a reactive component generates an electromagnetic field in both the reactive near-field region and the radiating far-field. A sensing circuit generates voltage and/or current having at least one of real and imaginary components that are proportional to an electromagnetic field in at least one of the reactive near-field region and the radiating far-field region. An electromagnetic modifier minimizes the electromagnetic field in the reactive near-field region in response to the signal generated at the output of the electromagnetic sensor.

Abstract: A method of interference suppression with intermodulation distortion mitigation includes processing an RF signal comprising an RF signal of interest and an RF interfering signal to produce a first and second RF drive signal each with a desired RF interference signal power and having a 90 degree relative phase. The first RF drive signal is imposed onto a first optical signal with a modulator to generate a first modulated optical signal so that the modulator has a large-signal behavior that is characterized by a Bessel function of the first kind J1(?), wherein the desired power at a frequency of the interference signal of the first drive signal is chosen to correspond to a zero of the Bessel function of the first kind J1(?).

Abstract: A same-aperture any-frequency simultaneously transmit and receive (STAR) system includes a signal connector having a first port electrically coupled to an antenna, a second port electrically coupled to a transmit signal path, and a third port electrically coupled to receive signal path. The signal connector passes a transmit signal in the transmit signal path to the antenna and a receive signal in the receive signal path. A signal isolator is positioned in the transmit signal path to remove a residual portion of the receive signal from transmit signal path. An output of the signal isolator provides a portion of the transmit signal with the residual portion of the receive signal removed. A signal differencing device having a first input electrically coupled to the output of the signal isolator and a second input electrically coupled to the third port of the signal connector subtracts a portion of the transmit signal in the receive signal path thereby providing a more accurate receive signal.

Abstract: A same-aperture any-frequency simultaneously transmit and receive (STAR) system includes a signal connector having a first port electrically coupled to an antenna, a second port electrically coupled to a transmit signal path, and a third port electrically coupled to receive signal path. The signal connector passes a transmit signal in the transmit signal path to the antenna and a receive signal in the receive signal path. A signal isolator is positioned in the transmit signal path to remove a residual portion of the receive signal from transmit signal path. An output of the signal isolator provides a portion of the transmit signal with the residual portion of the receive signal removed. A signal differencing device having a first input electrically coupled to the output of the signal isolator and a second input electrically coupled to the third port of the signal connector subtracts a portion of the transmit signal in the receive signal path thereby providing a more accurate receive signal.

Abstract: A method of separating a desired signal from an undesired signal includes obtaining a total input signal comprising the desired signal and the undesired signal in a time domain occupying a time duration from time t1 to time t2 of a single symbol in the desired signal. A transform is performed of the total input signal wherein an output of the transform is a time domain signal representing the desired signal.

Abstract: A linearized electro-optic modulator includes a substrate comprising a first Mach Zehnder interferometer comprising a first and second optical waveguide and a second Mach Zehnder interferometer comprising a first and a second optical waveguide. A signal electrode is positioned on the substrate to receive a modulation signal. First and second ground electrodes are positioned on the substrate and are electrically connected to ground potential. The signal electrode and the first and second ground electrodes are positioned so that an electric field generated by the signal electrode modulates both the first and second Mach Zehnder interferometers to generate a first and a second linearized modulated optical signal.

Abstract: A same-aperture any-frequency simultaneously transmit and receive (STAR) system includes a signal connector having a first port electrically coupled to an antenna, a second port electrically coupled to a transmit signal path, and a third port electrically coupled to receive signal path. The signal connector passes a transmit signal in the transmit signal path to the antenna and a receive signal in the receive signal path. A signal isolator is positioned in the transmit signal path to remove a residual portion of the receive signal from transmit signal path. An output of the signal isolator provides a portion of the transmit signal with the residual portion of the receive signal removed. A signal differencing device having a first input electrically coupled to the output of the signal isolator and a second input electrically coupled to the third port of the signal connector subtracts a portion of the transmit signal in the receive signal path thereby providing a more accurate receive signal.

Abstract: A method of separating a desired signal from an undesired signal includes obtaining a total input signal comprising the desired signal and the undesired signal in a time domain occupying a time duration from time t1 to time t2 of a single symbol in the desired signal. A transform is performed of the total input signal wherein an output of the transform is a time domain signal representing the desired signal.

Abstract: A same-aperture any-frequency simultaneously transmit and receive (STAR) system includes a signal connector having a first port electrically coupled to an antenna, a second port electrically coupled to a transmit signal path, and a third port electrically coupled to receive signal path. The signal connector passes a transmit signal in the transmit signal path to the antenna and a receive signal in the receive signal path. A signal isolator is positioned in the transmit signal path to remove a residual portion of the receive signal from transmit signal path. An output of the signal isolator provides a portion of the transmit signal with the residual portion of the receive signal removed. A signal differencing device having a first input electrically coupled to the output of the signal isolator and a second input electrically coupled to the third port of the signal connector subtracts a portion of the transmit signal in the receive signal path thereby providing a more accurate receive signal.

Abstract: A same-aperture any-frequency simultaneously transmit and receive (STAR) system includes a signal connector having a first port electrically coupled to an antenna, a second port electrically coupled to a transmit signal path, and a third port electrically coupled to receive signal path. The signal connector passes a transmit signal in the transmit signal path to the antenna and a receive signal in the receive signal path. A signal isolator is positioned in the transmit signal path to remove a residual portion of the receive signal from transmit signal path. An output of the signal isolator provides a portion of the transmit signal with the residual portion of the receive signal removed. A signal differencing device having a first input electrically coupled to the output of the signal isolator and a second input electrically coupled to the third port of the signal connector subtracts a portion of the transmit signal in the receive signal path thereby providing a more accurate receive signal.

Abstract: A same-aperture any-frequency simultaneously transmit and receive (STAR) system includes a signal connector having a first port electrically coupled to an antenna, a second port electrically coupled to a transmit signal path, and a third port electrically coupled to receive signal path. The signal connector passes a transmit signal in the transmit signal path to the antenna and a receive signal in the receive signal path. A signal isolator is positioned in the transmit signal path to remove a residual portion of the receive signal from transmit signal path. An output of the signal isolator provides a portion of the transmit signal with the residual portion of the receive signal removed. A signal differencing device having a first input electrically coupled to the output of the signal isolator and a second input electrically coupled to the third port of the signal connector subtracts a portion of the transmit signal in the receive signal path thereby providing a more accurate receive signal.

Abstract: A same-aperture any-frequency simultaneously transmit and receive (STAR) system includes a signal connector having a first port electrically coupled to an antenna, a second port electrically coupled to a transmit signal path, and a third port electrically coupled to receive signal path. The signal connector passes a transmit signal in the transmit signal path to the antenna and a receive signal in the receive signal path. A signal isolator is positioned in the transmit signal path to remove a residual portion of the receive signal from transmit signal path. An output of the signal isolator provides a portion of the transmit signal with the residual portion of the receive signal removed. A signal differencing device having a first input electrically coupled to the output of the signal isolator and a second input electrically coupled to the third port of the signal connector subtracts a portion of the transmit signal in the receive signal path thereby providing a more accurate receive signal.

Abstract: An electromagnetic interface having an impedance with a resistive and a reactive component generates an electromagnetic field in both the reactive near-field region and the radiating far-field. A sensing circuit generates voltage and/or current having at least one of real and imaginary components that are proportional to an electromagnetic field in at least one of the reactive near-field region and the radiating far-field region. An electromagnetic modifier minimizes the electromagnetic field in the reactive near-field region in response to the signal generated at the output of the electromagnetic sensor.

Abstract: A radio frequency (RF) signal separation and suppression system includes an input that couples in a radio frequency signal comprising desired and undesired radio frequency signals. The RF signal separation and suppression system also includes a reproduction generator connected to the input. The reproduction generator produces a reproduction from the radio frequency signal of the undesired signal at an output. The RF signal separation and suppression system also includes an electrical subtractor having a first input that is electrically connected to the output of the reproduction generator and a second input that is electrically connected to the input of the radio frequency signal separation system. An output of the subtractor generates an output radio frequency signal comprising the desired radio frequency signal and a suppressed undesired radio frequency signal.