Abstract: An electromagnetic field optimization apparatus providing a means of more independently modifying the field in either the reactive near-field region or the far-field region while having significantly less modification to the other field. This means that a design to affect the real component of the impedance that affects the radiation in the far-field region does not affect, or minimally affects, the reactive component of the impedance that affects the field in the reactive near-field region.

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 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: An electro-optic modulator includes a Mach-Zehnder interferometer having a bias input, an optical input, and an optical output. A first arm comprises an optical waveguide. A second arm comprises an optical waveguide. A plurality of electrode segments is distributed along or proximate to a length of the optical waveguides of the first and second arms. A plurality of amplifiers, where at least one of the plurality of amplifiers has an RF input that receives an electrical modulation signal, and where each of the plurality of amplifiers are electrically connected to one of the plurality of electrode segments so as to provide distributed gain. A number of the plurality of amplifiers is chosen to achieve a desired combination of noise figure and spur-free dynamic range.

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 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.

Abstract: An electromagnetic field optimization apparatus providing a means of more independently modifying the field in either the reactive near-field region or the far-field region while having significantly less modification to the other field. This means that a design to affect the real component of the impedance that affects the radiation in the far-field region does not affect, or minimally affects, the reactive component of the impedance that affects the field in the reactive near-field region.

Abstract: An electro-optic modulator includes a Mach-Zehnder interferometer having a bias input, an optical input, and an optical output. A first arm comprises an optical waveguide. A second arm comprises an optical waveguide. A plurality of electrode segments is distributed along or proximate to a length of the optical waveguides of the first and second arms. A plurality of amplifiers, where at least one of the plurality of amplifiers has an RF input that receives an electrical modulation signal, and where each of the plurality of amplifiers are electrically connected to one of the plurality of electrode segments so as to provide distributed gain. A number of the plurality of amplifiers is chosen to achieve a desired combination of noise figure and spur-free dynamic range.

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 bi-directional signal interface includes a carrier signal source that generates a carrier traveling wave at an output. A first traveling wave structure includes a first and a second waveguide having an input that is coupled to the output of the carrier signal source. The first and second waveguide propagate the carrier traveling wave. A second traveling wave structure includes an outgoing signal port that receives an outgoing signal and a bi-directional signal port that receives an incoming electrical signal and provides the outgoing signal. The first and second traveling wave structures have an electromagnetic interaction region with a geometry that is chosen for a desired outgoing-to-incoming signal isolation. A detector having an input coupled to the output of the first traveling wave structure generates an electrical signal related to the incoming electrical signal.

Abstract: An apparatus for determining V? of an optical modulator includes an RF source that generates a variable power RF modulation signal for modulating an optical modulator. An optical detector detects a modulated optical signal generated by the optical modulator and generates an electrical detection signal in response to the detected modulated optical signal. An RF power meter measures an RF detection signal power to determine a minimum RF detection signal power, an RF modulation signal power corresponding to the minimum RF detection signal power being used to calculate V? of the optical modulator.

Abstract: Approaches to bias control are disclosed for an optical modulator that modulates an optical carrier with a data input signal. In one embodiment an electrical bias input signal provided to the modulator is adjusted based on a characteristic of the data input signal detected from the modulated optical output signal. Another embodiment injects an additive dither signal into an optical modulator receiving a data input signal having a modulation depth of at least on the order of 50%. These embodiments can obtain and maintain a correct bias point on a modulator's transfer function curve when the modulation signal has a modulation depth on the order of 100%.

Abstract: An apparatus for determining V? of an optical modulator includes an RF source that generates a variable power RF modulation signal for modulating an optical modulator. An optical detector detects a modulated optical signal generated by the optical modulator and generates an electrical detection signal in response to the detected modulated optical signal. An RF power meter measures an RF detection signal power to determine a minimum RF detection signal power, an RF modulation signal power corresponding to the minimum RF detection signal power being used to calculate V? of the optical modulator.