Abstract: Disclosed herein is a swappable modular-based radiofrequency (RF) frontend that is reconfigurable to form transmitting (TX) and receiving (RX) phased array systems for diverse applications. Such swappable RF frontend may be used with unique spatial and spectral optical processing of complex RF signals over an ultra-wide frequency band. The swappable RF front end may be used in conjunction with an optically upconverted imaging receiver and/or in conjunction with optically addressed phased array technologies transmitters.

Abstract: Disclosed herein is a swappable modular-based radiofrequency (RF) frontend that is reconfigurable to form transmitting (TX) and receiving (RX) phased array systems for diverse applications. Such swappable RF frontend may be used with unique spatial and spectral optical processing of complex RF signals over an ultra-wide frequency band. The swappable RF front end may be used in conjunction with an optically upconverted imaging receiver and/or in conjunction with optically addressed phased array technologies transmitters.

Abstract: A charge-compensated modified uni-traveling carrier (CC-MUTC) photodiode comprising a semiconductor substrate and a stack of functional layers including a p-contact layer stacked on and in contact with the semiconductor substrate, an absorber layer stacked on the p-contact layer, a cliff layer stacked on the absorber layer, a drift layer stacked on the cliff layer, and an n-contact layer stacked on the drift layer. The CC-MUTC photodiode further comprises a first metal contact in contact with the p-contact layer and a second metal contact in contact with the n-contact layer.

Abstract: A method of RF signal processing comprises receiving an incoming RF signal at each of a plurality of antenna elements that are arranged in a first pattern. The received RF signals from each of the plurality of antenna elements are modulated onto an optical carrier to generate a plurality of modulated signals that each have at least one sideband. The modulated signals are directed along a corresponding plurality of optical channels with outputs arranged in a second pattern corresponding to the first pattern. A composite optical signal is formed using light emanating from the outputs of the plurality of optical channels. Non-spatial information contained in at least one of the received RF signals is extracted from the composite signal.

Abstract: This disclosure is directed to two-dimensional conformal optically-fed phased arrays and methods for manufacturing the same. The method includes providing a wafer substrate, depositing a first cladding layer on the wafer substrate, and depositing a core layer on the first cladding layer. The method further includes photolithographically patterning the core layer to provide a plurality of optical waveguide cores, and depositing a second cladding layer on the core layer to cover the plurality of optical waveguide cores to provide a plurality of optical waveguides. In addition, the method includes forming a plurality of antennas on the second cladding layer, each antenna of the plurality of antennas located near a termination of a corresponding optical waveguide of the plurality of optical waveguides, and providing a plurality of photodiodes on the second cladding layer, each photodiode of the plurality of photodiodes connected to a corresponding antenna.

Abstract: In certain embodiments, a system includes an optical switch matrix, an optical lens coupled to the switch matrix, and a wireless transmitter coupled to the lens. The switch matrix is configured to switch first optical signals from input ports to output ports of the switch matrix, and output second optical signals that are based at least partially on the first optical signals. The lens is configured to transform wave formats of the second optical signals based on the output ports over which the second optical signals are received. The transmitter includes an antenna array and circuitry coupled to the array. The circuitry is configured to receive the second optical signals from the lens, convert the second optical signals into beamformed wireless signals in accordance with the transformed formats, and transmit the beamformed wireless signals, which signals have spatial characteristics in accordance with the transformed formats, over the array.

Abstract: A method of RF signal processing comprises receiving an incoming RF signal at each of a plurality of antenna elements that are arranged in a first pattern. The received RF signals from each of the plurality of antenna elements are modulated onto an optical carrier to generate a plurality of modulated signals that each have at least one sideband. The modulated signals are directed along a corresponding plurality of optical channels with outputs arranged in a second pattern corresponding to the first pattern. A composite optical signal is formed using light emanating from the outputs of the plurality of optical channels. Non-spatial information contained in at least one of the received RF signals is extracted from the composite signal.

Abstract: This disclosure is directed to two-dimensional conformal optically-fed phased arrays and methods for manufacturing the same. The method includes providing a substrate, depositing a first cladding layer on the substrate, and depositing a core layer on the first cladding layer. The method further includes photolithographically patterning the core layer to provide a plurality of optical waveguide cores, and depositing a second cladding layer on the core layer to cover the plurality of optical waveguide cores to provide a plurality of optical waveguides. In addition, the method includes forming a plurality of antennas on the second cladding layer, each antenna of the plurality of antennas located near a termination of a corresponding optical waveguide of the plurality of optical waveguides, and providing a plurality of photodiodes on the second cladding layer, each photodiode of the plurality of photodiodes connected to a corresponding antenna.

Abstract: In certain embodiments, an apparatus includes a switch matrix and frequency band isolation circuitry. The switch matrix is configured to receive, at an input port, an electrical signal, which corresponds to a transmission signal received at antennas of an antenna array. The transmission signal corresponds to a transmission spatial sector of the array. The electrical signal includes first and second signal portions in first and second frequency bands, respectively, the electrical signal having been generated from an optical signal that corresponds to the transmission signal. The switch matrix is configured to direct, via an output port and in accordance with a control signal, the electrical signal to a first of multiple signal conversion paths.

Abstract: A lithium niobate on insulator (LNOI) optical waveguide including a first region, a second region, and a third region, a substrate layer extending across the first region, the second region, and the third region, and a first cladding layer disposed on the substrate layer across the first region, the second region, and the third region. The LNOI optical waveguide further includes a lithium niobate (LN) layer disposed on the first cladding layer across the first region and the second region.

Abstract: Disclosed herein is a swappable modular-based radiofrequency (RF) frontend that is reconfigurable to form transmitting (TX) and receiving (RX) phased array systems for diverse applications. Such swappable RF frontend may be used with unique spatial and spectral optical processing of complex RF signals over an ultra-wide frequency band. The swappable RF front end may be used in conjunction with an optically upconverted imaging receiver and/or in conjunction with optically addressed phased array technologies transmitters.

Abstract: An RF receiver may include antenna elements to receive RF signals, and electro-optic modulators to generate corresponding upconverted optical signals by mixing an RF signal with an optical carrier beam. The RF receiver may include a transmission array having a first bundle of optical waveguides that receive and transmit upconverted optical signals from their ends. The ends may be arranged in a first pattern. The RF receiver may include an interference space to receive the upconverted optical signals to form a composite beam, and an array of single mode optical fibers that have lenses positioned in a detection plane to receive a portion of the composite beam. The first pattern of the ends generates an RF emitter interference pattern at the detection plane, and the single mode optical fiber lenses have a geometric arrangement that corresponds to the first RF emitter interference pattern.

Abstract: An RF receiver may include antenna elements to receive RF signals, and electro-optic modulators to generate corresponding upconverted optical signals by mixing an RF signal with an optical carrier beam. The RF receiver may include a transmission array having a first bundle of optical waveguides that receive and transmit upconverted optical signals from their ends. The ends may be arranged in a first pattern. The RF receiver may include an interference space to receive the upconverted optical signals to form a composite beam, and an array of single mode optical fibers that have lenses positioned in a detection plane to receive a portion of the composite beam. The first pattern of the ends generates an RF emitter interference pattern at the detection plane, and the single mode optical fiber lenses have a geometric arrangement that corresponds to the first RF emitter interference pattern.

Abstract: An RF pulse generator may comprise a pair of phase-locked lasers that output optical tones offset in frequency by a set amount. The resulting optical signal is periodically transmitted and blocked by an optical switch to generate a pulsed optical signal. A photodiode is irradiated with the pulsed optical signal to generate a corresponding pulsed RF signal having a frequency corresponding to the frequency difference of the optical tones generated by the phase-locked lasers. An antenna may be connected to and driven by the photodiode to electromagnetically transmit the pulsed RF signal.

Abstract: Disclosed herein is a swappable modular-based radiofrequency (RF) frontend that is reconfigurable to form transmitting (TX) and receiving (RX) phased array systems for diverse applications. Such swappable RF frontend may be used with unique spatial and spectral optical processing of complex RF signals over an ultra-wide frequency band. The swappable RF front end may be used in conjunction with an optically upconverted imaging receiver and/or in conjunction with optically addressed phased array technologies transmitters.

Abstract: In the disclosed optically-fed transmitting phased-array architecture, transmitting signals are converted between the electrical domain and the optical domain by using electro-optic (EO) modulators and photodiodes. RF signal(s) generated from a relatively low frequency source modulate an optical carrier signal. This modulated optical signal can be remotely imparted to photodiodes via optical fibers. Desired RF signals may be recovered by photo-mixing at the photodiodes whose wired RF outputs are then transmitted to radiating elements of the antennas. The antenna array may generate a physical RF beam that transmits an RF signal that is focused on one or more selectable locations. Multiple RF beams may be simultaneously generated, each RF beam being capable of being directed to focus on a unique location or set of locations.

Abstract: A method of RF signal processing comprises receiving an incoming RF signal at each of a plurality of antenna elements that are arranged in a first pattern. The received RF signals from each of the plurality of antenna elements are modulated onto an optical carrier to generate a plurality of modulated signals that each have at least one sideband. The modulated signals are directed along a corresponding plurality of optical channels with outputs arranged in a second pattern corresponding to the first pattern. A composite optical signal is formed using light emanating from the outputs of the plurality of optical channels. Non-spatial information contained in at least one of the received RF signals is extracted from the composite signal.

Abstract: A method of RF signal processing comprises receiving an incoming RF signal at each of a plurality of antenna elements that are arranged in a first pattern. The received RF signals from each of the plurality of antenna elements are modulated onto an optical carrier to generate a plurality of modulated signals that each have at least one sideband. The modulated signals are directed along a corresponding plurality of optical channels with outputs arranged in a second pattern corresponding to the first pattern. A composite optical signal is formed using light emanating from the outputs of the plurality of optical channels. Non-spatial information contained in at least one of the received RF signals is extracted from the composite signal.

Abstract: Example embodiments disclose a tunable optical pair source (TOPS) configured to generate first and second output optical beams having respective first and second frequencies that are phase locked with each other. The TOPS may include a first laser, such as a tunable laser, configured to generate a first laser beam, a radio frequency (RF) oscillator configured to transmit an RF reference signal, a beam splitter in optical communication with the first laser, and an electro-optic modulator configured to modulate the second split beam with the RF reference signal to form a modulated beam having a first sideband comb comprising a plurality of harmonics. Additionally, the TOPS may include an optical filter configured to receive the modulated beam and output a filtered optical beam, and a second laser configured to generate a second laser beam at the second frequency, the second laser being configured to receive the filtered optical beam as a seed.

Abstract: A hyperspectral radiometer may comprise one or more antennas, a electro-optical modulator modulating the received RF signal onto an optical carrier to generate a modulated signal having at least one sideband; a filter filtering the modulated signal to pass the sideband to a photodetector; and a photodetector producing an electrical signal from which information of the RF signal can be extracted. In some examples, the optical sideband may be spatially dispersed to provide a plurality of spatially separate optical components to the photodetector, where the spatially separate optical components having different frequencies and correspond to different frequencies of the received RF signal. In some examples, the passed sideband may be mixed with an optical beam having a frequency offset from the optical carrier to form a combined beam having at least one optical signal component having a beat frequency from which information of the RF signal can be extracted.