Phase Sensitive Innovations, Inc. | Date: 2016-08-03
An optical imaging system and method that reconstructs RF sources in k-space by utilizing interference amongst modulated optical beams. The system and method involves recording with photodetectors the interference pattern produced by RF-modulated optical beams conveyed by optical fibers having unequal lengths. The photodetectors record the interference, and computational analysis using known tomography reconstruction methods is performed to reconstruct the RF sources in k-space.
Phase Sensitive Innovations, Inc. | Date: 2016-08-19
An optically-fed tightly-coupled array (TCA) antenna comprises a plurality of photodiodes and antennas. Each photodiode may receive an optical signal from an optical fiber and convert the optical signal into an RF driving signal to drive a corresponding antenna to which it is connected. Each photodiode may be connected to the antenna. In some examples, the TCA is capable of ultra-wideband operation ranging from 2-12 GHz and wide beam-steering capability up to 40 from the broadside. Inductance peaking and resistance matching may be employed.
Phase Sensitive Innovations, Inc. | Date: 2016-12-06
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.
Phase Sensitive Innovations, Inc. | Date: 2017-05-10
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.
Phase Sensitive Innovations, Inc. | Date: 2017-01-19
An transmitter to be used in wireless multi-user MIMO has been described above. The system combines the virtues of digital, analog and optical processing to arrive at a solution for scalable, non-blocking, simultaneous transmission to multiple UE-s. The system architecture is independent of the RF carrier frequency, and different frequency bands can be accessed easily and rapidly by tuning the optical source (TOPS). The data channels are established in the digital domain and the RF beam-forming accuracy is only limited by the available resolution of DAC, which can be as high as 16 bits for 2.8 GSPS in off-the-shelf components.
Agency: Department of Defense | Branch: Air Force | Program: STTR | Phase: Phase I | Award Amount: 149.96K | Year: 2015
ABSTRACT: Under the proposed effort, PSI will leverage a novel pmmW imaging technology developed under a prior Navy program to realize the low size, weight, and power sensors required for UAV implementation. This technology is based on an optical upconverted distributed aperture technology that can make use of the full aperture of the aircraft thereby maximizing achievable resolution. This sensor technology has already reached TRL 6 with successful flight tests on rotorcraft for DVE mitigation. Key elements of this effort will be to further reduce and integrate the sensor nodes and optical processor to make the technology better suited for the stricter SWaP constraints imposed by UAV platforms. Additionally, under this effort PSI will utilize existing phenomenology modelling tools and data from previous flight tests to develop sensor requirements and CONOPs for UAV navigation using pmmW sensors. These same modelling tools will also be utilized to predict the ability of the sensor to track navigation paths in terrain and geographic databases when operating in GPS denied environments. Based on these findings a preliminary sensor design for a representative UAV platform will be started in Phase I to be built as a deliverable under a Phase II effort, if awarded.; BENEFIT: The potential applications for PSIs technology and its capabilities are significant and could have a appreciable impact in many application areas. Traditional imaging modalities which exist mainly in the infrared (IR) for night vision and visible regions for daylight imaging are vulnerable to extreme scattering losses in harsh conditions. Millimeter-wave radiation is attenuated millions of times less in clouds, fog, smoke, snow, and sandstorms than visual or IR radiation. This enables millimeter wavelength imaging systems to see-through the obscurants in day or night conditions. A list of potential applications includes: (1) marine navigation in dense fog and inversion layers with passive imaging systems; (2) navigational aids for landing aircraft in adverse weather, operating emergency response vehicles in poor weather or smoke, piloting ships in poor-visibility conditions, and monitoring highways for traffic safety; (3) military surveillance and target acquisition in inclement weather with potential use on unmanned autonomous vehicles (UAVs); (4) enhanced visualization in smoke and fog, providing superior performance over infrared systems for locating victims and navigating within a fire zone; (5) non-intrusive portal security whose use would proliferate in airports, embassies, government and landmark buildings, schools, sports arenas, etc.; (6) scanners at the more than 300 ports of entry into the U.S. to look simultaneously for weapons and contraband without the need for multiple sensors; (7) stand-off frisking, providing police and security guards with the ability to detect concealed objects without the need for a physical search. More specifically, many military, security, environmental, and commercial opportunities exist for an affordable, easy to deploy system that is able to image through clothing and in harsh atmospheric condition. Passive millimeter wave imaging has the advantage over visual and infrared systems of being a near all-weather surveillance system with the ability to see through clouds and most adverse weather conditions with equal day and night sensitivity. Commercially, fog, mist, and rain cost airlines around the world billions of dollars each year in delays and rerouting. There is also the intangible cost of customer dissatisfaction. Even though Instrument Landing Systems (ILS) can help reduce weather-related flight cancellations at major airports, thousands of flights each year are canceled or delayed at smaller airports that do not have the benefit of these extensive radar and communication systems. Even with these systems, landing in inclement weather would be vastly safer and easier if pilots had a system that could see through the rain to the ground below. Civilian air transportation would benefit greatly from the proposed systems which could aid pilots in landing and navigating during Category III conditions. In such conditions now, landings are not permitted. Another large aviation market is airport security. The U.S. government has spent $15 billion on aviation screening between September 11, 2001 and 2005. Millimeter-wave imaging systems could safely and effectively monitor passengers as they enter the terminals for hidden contraband and weapons. These systems can remotely detect metallic and non-metallic threats and let security know exactly the physical location of the threat. With hundreds of commercial airports, thousands of commercial aircraft, tens of thousands of daily flights, and millions of passengers using the system daily, providing security to the nations commercial aviation system is clearly a daunting challenge. A 2007 National Academies Press book entitled Assessment of Millimeter-Wave and Terahertz Technology for Detection and Identification of Concealed Explosives and Weapons recommended that the Transportation Security Administration should follow a two-pronged investment strategy: 1.) Focus on millimeter-wave imaging as a candidate system for evaluation and deployment in the near term, and 2.) Invest in research and development and track national technology developments in the terahertz region. The development of a light weight, compact, easy to deploy, lower cost millimeter wave imaging system would open up these far reaching possibilities, representing not only an impressive leap forward in our technical capabilities but also a tremendous business opportunity. Millimeter wave imaging technology promises to establish markets in security, navigation, defense, rescue and surveillance, industrial automation, and meteorology, which are projected to grow into multi-billion-dollar segments in our national economy. PSI is uniquely positioned to directly transition this technology into the market. A lightweight, platform distributed pmmW imager, as will be developed under the proposed effort, will directly enable application to a wide range of government and commercial customers. Additionally, the navigation and guidance tools that will be developed under this effort will further expand the utility of pmmW sensors for commercial aircraft and military applications alike. PSI is continuing to develop a passive/active mmW landing aid for rotorcraft under an Army SBIR Phase II program and has received significant investment (~$1M) from one DoD prime to transition the pmmW sensor for use as a mmW landing aid in degraded visual environments. The development of integrated sensor nodes and miniaturized processors, such as the ones proposed in this effort, would directly supplement these landing aids, yielding improved performance and adding capabilities to the imaging system. Thus, these efforts will lead to a technology that will directly and immediately aid the warfighter as part of a suite of solutions for brownout mitigation for which PSI is already on a path to transition to the US military and is in direct talks with more than one prime defense contractor to transition to production.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 79.99K | Year: 2016
Submarine applications for antennas are severely constricted by mission constraints for stealth and force protection. High fidelity fiber optic links could potentially open a new range of mission capabilities by enabling towed antenna arrays that could be accessed while submerged. However, to date RF photonic links have had insufficient noise performance and/or dynamic range to satisfy these mission requirements. To this end, PSI proposed a series of component and link architecture developments that will provide improved performance over the existing state of the art. Specifically, PSI will utilize its expertise in high bandwidth lithium niobate modulators and high-linearity MUTC photodiodes to establish a baseline of performance that can be achieved using traditional link architectures that exceeds existing commercial solutions. This effort will be dovetailed with explorations into optically downconverted links that utilize injection locked lasers to convert the received frequency down to baseband directly in the optical domain, where very high photocurrent detectors can be used for enhanced link performance. Furthermore, vertically integrated optical phase locked loop receivers with delays times on the order of femtoseconds will be explored to realize high dynamic range links with phase feedback that have previously been limited in dynamic range improvement and operational bandwidth.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 749.78K | Year: 2015
ABSTRACT:In this phase II effort we will commercialize the high speed, high power, modified uni-traveling carrier (MUTC) photodiodes (PDs). To this end, we will develop reliable packaging solutions for discrete PDs, PD arrays, balanced PDs and waveguide based PDs. We will also transition the chip fabrication process for continuous, high volume supply of quality MUTC PD chips. In the first six months of phase I work we successfully packaged two prototype PD modules, and demonstrated 22GHz 3dB bandwidth and ~20dBm RF output power at 20GHz based on a 34μm-diameter diode. We have also started process development for MUTC PD chip fabrication with our own R&D funds. Based on phase I package design, we will package PD array and balanced PDs. We will also dramatically reduce the package SWaP using parallel-fed package architecture. We will collaborate with Prof. Campbell and his UVA group in developing flip-chip-comparable MUTC based waveguide PDs and diamond based chip-level integration. As a result, we will build a production family of MUTC high power PDs. We will also apply the PDs and PD modules that we developed in phase II work to related projects, such as high frequency RF generation and optical-feed phased antenna array.BENEFIT:The potential applications for high speed, high power MUTC PDs, PD array, balanced PD receiver and waveguide PDs are vast and could have a profound impact on our society. Today, as the high frequency microwave, millimeter wave and terahertz range are rapidly explored, photodiodes, especially ones with high output power, have become critical devices and indispensable ways of photonic link demodulation or high frequency signal generation. For example, generation of RF signal with enough power is very challenging, especially for very high frequency range, such as w-band. Among all the solutions, optical based methods that rely on high-frequency and high-power PDs are greatly favored due to their wide bandwidth and configurability. In addition, traditional photodiodes are made for detection of photonic input signal amplitude. A balanced PD receiver, however, is capable of detecting not only the signal amplitude, but also the phase information. As a result, a balanced PD detector is compatible with complex modulation formats such as DPSK and DQPSK. Today, as the high frequency microwave, millimeter wave and terahertz range are rapidly explored, photodiodes, especially ones with high output power and high linearity, have become critical devices and indispensable ways of photonic link demodulation or high frequency signal generation. For example, high power PD receivers have been investigated and applied for radio-on-fiber broadband wireless communications, which is propelled by the huge increase of data volume in recent years. According to Edholms law, the demand for point-to-point bandwidth in wireless short-range communications has doubled every 18 months over the last 25 years. It can be predicted that data rates of around 510Gb/s will be required in ten years. Tremendous market demands of high power PDs are expected by then. A list of potential applications of balanced high-power PD receiver includes: a) High frequency RF generation for spectroscopic applications including material detection and identification, imaging, tomography, cancer detection or genetic analysis. b) Millimeter wave wireless telecommunications. c) Long haul antenna remoting. d) Phased array antennas. e) Cable television. More specifically, PSI will commercialize the MUTC PD, PD array, balanced PD and waveguide PD to form a product family to cover high speed, high power photo detection up to 100GHz based on successful transition of the MUTC manufacturing processes and packaging process development. The commercialization process will be performed through the cooperation between PSI, UVA group and other industrial partners. PSI will seek and identify applications of high-frequency and high-power PDs in broadband phase array antennas and microwave photonic link system as a platform for multifunctional radar systems, where hundreds or thousands of PDs are required in a single system. To this end, packaged PD module with small size, light weight, low cost and easy-to-deploy interface not only represents an impressive leap forward in our technical capabilities but also a tremendous business opportunity.
Agency: Department of Defense | Branch: Army | Program: SBIR | Phase: Phase II | Award Amount: 789.32K | Year: 2015
Herein, PSI proposes to leverage extensive development in the area of optically sampled passive millimeter-wave imaging to develop dual mode active/passive imagers that provide both the intuitive, real-time imagery of a passive imager and the ranging capabilities of an active sensor. To accomplish this task, an optically sampled millimeter-wave receive array is sampled via optical pulsed laser gating of the detection array. These signals are then reconstructed using an all optical image processor that is capable of generating real-time image samples. The optically gated sampling of this array is driven in conjunction with an optically generated millimeter-wave source that can be gated and phase with unprecedented levels of flexibility. Under the Phase I effort, key risk areas in the realization of such active/passive imaging arrays have been mitigated and the Phase II efforts proposed herein will culminate in the fabrication of a prototype sensor to be delivered as part of this effort. Developments made under this effort will directly supplement a passive imaging technology that is currently on track for transition to a prime US defense contractor and, as such, has a direct and immediate transition path to US DoD applications.
Agency: Department of Defense | Branch: Army | Program: SBIR | Phase: Phase I | Award Amount: 149.83K | Year: 2015
Degraded visual environment (DVE) presents a challenge for helicopter pilotage, particularly in close proximity to potential hazards such as vegetation, poles, wires, buildings, vehicles, personnel, equipment, nearby terrain, other aircraft, or ship superstructures. To safely negotiate these hazards, the aircrew must maintain a continuous awareness of the environment that can include both static and moving obstacles. In the absence of direct visual cues in DVE, the crew must rely on other means to determine the location and movement of these hazards. Here, we propose the use of active millimeter-wave (mmW) imaging to provide information about the helicopter surroundings in full 3D. The approach relies on the movement of the main rotor for the scanning, and on a distributed mmW receiver concept with optical up-conversion and processing for detection. The captured signal contains all information necessary to determine the position and movement of objects in the vicinity of the helicopter as well as the state of the rotor. In addition, high-gain transmission and reception for communication is afforded by the large effective aperture. The goal of this Phase I SBIR is to establish the viability of the approach and to identify optimum system architectures.