NASA Glenn Research Center invites companies to license a new concept design for terrestrial satellite dishes and communications systems. Glenn’s Cellular Reflectarray Antenna has been developed and tested for use with next-generation Ka-band satellites, although it can be used with all bands of satellite communication. The design’s flat, planar configuration all but eliminates the wind-loading problems associated with larger parabolic reflectors for dish systems. The technology also offers unique features that provide ease of installation and improved signal reception while deterring piracy and theft of subscription satellite services.

After a chunk of foam insulation broke off of the external fuel tank during launch and damaged the Columbia space shuttle, causing it to burn up on reentry, finding a nondestructive method for evaluating sprayon foam insulation (SOFI) became a high priority for NASA. Terahertz (THz) imaging developed by Picometrix, Inc. was evaluated for detection of discrete flaws such as voids in the foams. Additionally, researchers at NASA Glenn Research Center designed a noncontact precision measurement method for determining thickness and density variations in dielectric materials, using terahertz energy.

Researchers at NASA Glenn Research Center have invented a packaging methodology for integrating a microphotonic millimeter wave receiver (MMWR) using a microphotonic resonate disk on a silicon substrate. Digital information is modulated with an optical beam using a microphotonic resonate disk. This optical beam carrying the digital data signal is coupled into a fiber-optic cable for transmission, providing better signal strength over long distances that is not prone to cross-talk or electromagnetic interface. Because it integrates the optical coupling mechanism onto a silicon substrate, this innovation eliminates the need for bulky equipment to translate the signal. The carrier structure can be made quite small and simple. The technology has wide applicability and can be used with cellular equipment, including pico-cells, local area networks, and “last mile” applications that take signals to the neighborhood level.

To achieve the clearest digital signal in a phase-modulated communications link, a signal must prevail against such environmental noise as weather interference, antenna misalignment, and transient power loss. An accurate assessment of the signal-to-noise ratio (SNR) enables the sender to adjust the transmission power to ensure that the communication can be completed successfully without using excess energy. Inventors at NASA Glenn Research Center have come up with a method to accurately assess the SNR in real time and eliminate the need for a separate, parallel baseline communication link to monitor the transmission quality. This technology improves the performance and reduces the cost of communications systems.

Researchers at NASA Glenn Research Center have developed an ultrasonic scan system to detect degradation in ceramic matrix composites and polymer matrix composites. The scanner reveals microdamage in composite materials that, on the surface, do not appear to have any flaws. Employing the guidedwave method, the scanner can be used in a singlepoint or conventional scanning mode, and can inspect even mildly curved surfaces.

Researchers at NASA’s Glenn Research Center have patented a High-Resolution Scanning Reflectarray Antenna (HRSRA) to track ground terminals and spacecraft communication applications. This HRSRA overcomes the limitations of parabolic dish antennas and direct radiating phased arrays, which provide only fixed beams and suffered inefficiencies caused by impedance mismatches between antenna elements and switching devices. In contrast, Glenn’s HRSRA improves the antenna structure to allow continuous variable phase shifting for full hemispherical coverage. The HRSRA integrates phase shifters on the same surface as the antenna elements by using coupled line structures layered on thin ferroelectric films. Using microstrip patch radiators capitalizes on the linear relationship between the phases of each element so that a single voltage can be applied across a single row or column of the array. This structure allows attainment of the appropriate phase shift for electronic scanning without any physical movement of the antenna to produce desired beam steering. It also combines the antenna and switching devices, thereby eliminating impedance mismatch.

Researchers at NASA’s Glenn Research Center have patented an improved multi-mode broadband patch antenna that can be tuned over a relatively broad frequency range for simultaneously receiving and transmitting at different selected frequencies. Patch antennas are highly desirable for commercial and military applications, such as low-Earth-orbiting communications and remote sensing satellites, because of their lightweight construction and inexpensive manufacturing techniques. Existing microstrip antennas have inherently narrow instantaneous bandwidth. Previous approaches to increase the bandwidth, by using low permittivity substrates or thick substrates, produced undesirable effects such as an increase in antenna size or the generation of surface waves that degrade efficiency. Glenn’s improved antenna assembly provides for the same aperture to be used at independent frequencies such as reception at 19 GHz and transmission at 29 GHz. The multi-mode broadband patch antenna includes a ground plane comprised of a conductive material along with a radiator and a ferroelectric film that allows for tuning over a relatively large frequency range.
The antenna can be fabricated in a relatively inexpensive manner, using conventional photolithography techniques commonly used to create semiconductors and printed circuits.
 

Innovators at NASA’s Glenn Research Center have patented a planar velocity measurement system and method that require only a single line of sight to measure all three velocity components of a fluid field flow across an illuminated plane. Existing systems for planar velocity measurement of fluid flows generally incorporate either particle imaging velocimetry (PIV) or Doppler global velocimetry (DGV). Both methods are capable of providing three-component flow field measurements but require multiple access ports or very wide access ports to achieve accurate results. These methods present a challenge for many flow field velocity measurement platforms (such as aerospace propulsion testing) in which optical access is extremely limited. Glenn’s innovation overcomes this challenge by providing a system and method for obtaining planar three-component velocity measurements of fluid flows through a single limited-access optical viewing port. The flow is seeded with small particles that accurately follow the flow field fluctuations. The field itself is illuminated with pulsed laser light and the positions of the particles in the flow are recorded with electronic charged coupled device (CCD) cameras. In-plane velocities are determined by measuring particle displacements, while the out-of-plane velocity component is determined by measuring the Doppler shift of the light scattered by the particles. Gas and liquid velocities as well as two-phase flows can be measured using this method.

Researchers at NASA’s Glenn Research Center have patented an improved technique for fabricating defect-free nanometer-scale steps on single-crystal substrates such as silicon carbide (SiC). These nanometer-scale steps enable step-height calibration suitable for scanning probe microscopes and profilometers. The ability to have a step-height calibration device for measurement at multiple nanometers down to 1 nanometer and below was not available previously because commercially available single-crystal SiC substrates used to create steps contain defects that impact their quality, reproducibility, and utility. Glenn’s patented process creates nanometer-scale steps on SiC substrates using growth and etching processes that prevent defects. Patterned arrays of mesas (planar surfaces) are etched into a selected crystal plane. Atomic and nanometer scale steps are produced on top of the mesa surface through growth and etching processes. This structure can then provide step-height calibration from less than 1 nanometer to greater than 10 nanometers with no more than atomic scale local roughness.

Researchers at NASA’s Glenn Research Center have patented a method for creating an apparatus for combining radio frequency (RF) technology with micro-inductor antennas and signal processing circuits, particularly useful for in situ telemetrically monitored pressure/temperature sensors for minimally invasive surgery. These circuits are used for RF telemetry of real-time measured data from microelectromechanical (MEMS) and biomicroelectromechanical (Bio-MEMS) systems, sensors, and actuators. By using the electro-magnetic coupling with a remote powering/receiving device, the sensor has no need for a hard connection to an external power source. This is because the microminiaturized inductor has two distinct operating modes: the “charging mode,” where the inductor acts as a power charger for the device, and the “transmitting mode,” where the inductor acts as an antenna for transmitting RF telemetry signals. This new RF telemetry system is superior to former capacitive sensors and switches because the structure is simpler and it does not require the presence of a directly coupled power source.

Researchers at NASA’s Glenn Research Center have patented an electromechanical ultra-high-speed shutter mechanism, used particularly to enhance spectrometers by reducing background light. Prior inventions that use various shuttering techniques can suffer from background interference, low quantum efficiency, decreased signal-to-noise ratio, and low dynamic ranges. These prior techniques are also complex, difficult to build, and make it difficult to maintain desired shutter speed. Glenn’s invention overcomes these limitations by using multiple shutter mechanisms, specifically three low-speed, electronically phase-locked rotary choppers in conjunction with a reciprocating shutter or an oscillating shutter. These shutter mechanisms are electronically coupled using phase-locked loop electronics to avoid the use of ultra-high-speed motors or complicated gearing mechanisms. This current invention is useful for devices that produce short pulses of light from light sources, such as stroboscopes or high-repetition rate laser sources, or as fiber optic light gates at microsecond speeds, or as high-speed molecular beam shutters used in high-vacuum systems.

Researchers at NASA’s Glenn Research Center have patented a silicon carbide (SiC) anemometer (measurement device) able to withstand high temperatures, high turbulence, and high vibrations in turbine engines in order to help accurately assess an engine’s performance. Currently, accurate data on engine performance is difficult to achieve because sensors are adversely affected by high temperature, stresses imposed by differing materials, and electromagnetic noise. By providing direct measurement of engine parameters, this new device will improve data accuracy in simulations and increase confidence in computational fluid dynamics codes, thereby enhancing engine designs, increasing engine safety and efficient energy management, and improving emission control. The sensor’s cantilever beam and cavity substrates are manufactured from SiC and are able to withstand high temperatures and high vibrations. These parts endure a long thermal oxidation process to keep the surfaces from conducting electricity, ensuring uniformity in the readings generated by the sensor. Electrical connections are made by compression bonding, thereby eliminating problems associated with wire bonding in high temperature and high vibration environments. The invention can act as a stand-alone product with a plug-and-play capability, or can be permanently inserted into an engine as part of an overall health monitoring strategy. Because of the excellent thermomechanical properties of SiC, the cantilever beam can be inserted into sections of an engine, otherwise impossible with prior devices.

Researchers at NASA’s Glenn Research Center have patented a method of assembly for a silicon carbide (SiC) high-temperature anemometer (measurement device) used to assess conditions in an engine—critical to improving engine design for aviation safety, efficient energy management, and better emission control. Previous sensors used to measure conditions inside an engine are limited to low temperatures (less than 200 degrees Celsius). In addition, packaging materials used on these sensors can cause thermomechanical stresses that cause fatigue and degrade the sensor’s performance. In contrast, Glenn’s new sensor assembly and packaging uses SiC substrates and electrodes capable of withstanding high-temperature environments (up to 600 degrees Celsius). This method packages the anemometer so that it is semi-enclosed and uses a compression-bond technique that essentially eliminates the need for wire bonding that can cause stress on the sensor.

Researchers at NASA’s Glenn Research Center have patented a fluid flow sensor that reliably and cost-effectively measures the flow of a fluid moving through a chamber, such as required to maximize efficiency in internal combustion engines. Prior sensor devices (such as vane anemometers, thermal hot wire anemometers, and total pressure tubes) can be fragile, difficult to repair, require intrusive piping, may be affected by motion of the device, or may measure only a small portion of the entire flow. In contrast, Glenn’s sensor is comprised of an elongated thin quartz substrate with resistors spaced along the substrate within a velocity recovery region. Certain resistors detect temperature changes as the fluid flow moves across the substrate, providing an output signal that represents actual fluid flow. The specifically designed positioning and thermal sensing capabilities of the resistors allow the sensor to measure flow more accurately. The sensor fabrication requires no etching or multiplicity of layers, reducing manufacturing costs. It also can be easily scaled to any desired size for a particular application.

Researchers at NASA’s Glenn Research Center have patented a method for measuring three-dimensional particle velocities at multiple points in a fluid. This approach to stereo imaging velocimetry improves on flaws in previous methods such as particle images contaminated by noise sources, causing significant errors in velocity measurement and misidentification of particles. This new method employs at least two cameras that can be calibrated and whose particle images can be filtered and recorded for image processing and particle tracking. Particles are then stereo-matched to produce three-dimensional locations of the particles as a function of time so that velocity can be measured. An image reconstruction technique takes into account severe distortion to enable the reconstruction of incomplete calibration of images resulting in less loss of the field of view. A new approach to particle extraction and color image processing are also significant new developments in this technology.

Researchers at NASA’s Glenn Research Center have patented a method to produce silicon carbide (SiC) gas sensors using a SiC substrate with an atomically flat surface to eliminate performance degradations caused by poor SiC surface interface properties. This uniform surface improves on the reproducibility, stability, sensitivity, and electronic limitations of previously developed gas-sensing devices. The SiC semiconductor material on which gas sensors previously were fabricated has a stepped structure with varying bond densities that detrimentally cause variances in surface structure. This in turn produces interface defects believed to degrade gas sensor performance. In contrast, Glenn’s patented gas-sensing device is comprised of a gas-sensing layer residing on top of a single crystal SiC epilayer having an atomically flat surface, such that the detector produces a change in electrical signals when it senses the presence of a gas. A more uniform surface on which the SiC gas sensors are deposited is a significant advancement in the production of higher quality SiC-based gas sensors, and allows for increased commercial potential.

Researchers at NASA’s Glenn Research Center have patented a system that improves the common use of microscopes to analyze enlarged images of specimens. This invention relates to a Compact Microscope Imaging System (CMIS) with intelligent controls that provide techniques for scanning, identifying, detecting, and tracking microscopic changes and features of various surfaces (such as cells, spheres, and manufactured products). The CMIS system is a machine vision system that combines intelligent image processing with remote control capabilities. It provides the ability to auto-focus on a microscope sample, automatically scan an image, and perform machine vision analysis on multiple samples simultaneously. This improves on the analyses currently conducted by humans examining specimens under a microscope, since human outcomes are subjective and affected by concentration, fatigue, and distractions.

Researchers at NASA’s Glenn Research Center have patented a fiber-optic sensor system that remotely measures the concentration of molecular oxygen, nitrogen, hydrocarbon vapor, and other gases in a liquid fuel tank. In the area of aircraft safety, there is a need to eliminate the explosion hazard posed by the mixture of fuel vapors and oxygen contained in the space above a fuel tank. Prior techniques for gas measurement pose a potential hazard in that an electrically powered sensor connected by wires may provide a source of sparks or electrostatic ignition. Based on an optical sensor element and remotely located Raman spectrograph, Glenn’s innovation safely provides accurate and fast quantitative identification of gases. It provides measurements of the compositions of gaseous materials in liquid receptacles needed to determine the appropriate level of inerting required for safety. The system provides these data with accuracy better than 1 percent (by volume) over approximately 1 minute. This is a critically enabling sensor technology for the feedback control of on-board inert gas generation systems that are used in inert aircraft fuel tanks for the prevention of fuel tank explosion and fire. The result is a system with no potential safety hazards that reliably performs over wide temperature and pressure ranges.

Researchers at NASA’s Glenn Research Center have patented a device and fabrication method related to a new miniaturized Schottky diode hydrogen and hydrocarbon sensor. At high temperatures, many gas-detecting sensors are not able to maintain sensitivity and stability due to chemical reactions between their catalytic metal sensing layer and substrate layer. Typically, reactions between layers can lead to the formation of metal silicides that render the sensor insensitive to hydrogen and hydrocarbon materials. As a result, this leads to decreased hydrogen and hydrocarbon detection sensitivity and degradation of the sensor device. Glenn’s patented gas sensing structure is comprised of a catalytic sensing layer, a substrate layer of SiC, and a barrier interlayer located between the catalytic sensing layer and substrate layer. The major innovation of this work is the use of palladium oxide as this barrier layer to prevent detrimental reaction products (e.g., metal silicides). The sensor has high sensitivity and stability due to the strength of the barrier interlayer, and provides gas detection at temperatures ranging from at least 450 to 600 degrees Celsius.