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electrical and electronics

Smooth-Walled Feed Horn
The technology is a monotonically-profiled, smooth-walled scalar feed horn optimized between 33 and 45 GHz. The phase center for this horn is near the aperture and is stable in frequency. The feed horns monotonic profile is compatible with machining by progressive plunge milling in which successively more accurate tools are used to realize the feed profile. This technique has been used for individual feeds and is potentially useful for fabricating large arrays of feed horns, such as multimode Winston concentrators, direct-machined smooth-walled conical feed horns, and for dual-mode feed horns.
Instrumentation

Wideband, Subharmonic Mixer for Spectrometers
The novel mixer offers wideband and sub-harmonic conversion capabilities for enhanced signal processing across a broad frequency range. The mixer operates at 470-600 GHz and includes a LO waveguide to allow 265-300 GHz input signal and a radio frequency (RF) waveguide for the 470-600 GHz operation. The LO and RF signal multiply and down-convert the RF signal to an IF signal to a much lower frequencies for further digitization. The mixer is designed on a gold and quartz substrate for a lower dielectric constant. The filter design uses a triangular patch resonator-based low-pass filter to reduce the size of the mixer as well as isolates the LO signal and the wide IF signal. Additionally, an IF filter, RF filter, Schottky diode, LO, and RF probes are integrated into a single chip to further reduce the dimensions of the mixer. The invention also leverages an antiparallel diode orientation, where the LO frequency is half of the RF input. This LO signal is amplified and multiplied up to 265-300 GHz to provide an input power of 3-5 mW to pump the antiparallel mixer.
The technology offers significant advantages in remote sensing and high-speed communications, enabling simultaneous detection of multiple molecular species and enhancing the efficiency of submillimeter-wave heterodyne spectrometers. The wideband functionality achieves high data rates required in emerging 6G networks and offers exceptional sensitivity, with prototype tests showing a conversion loss below 12 dB and noise temperatures under 4000 K at 470 GHz. The integration of components such as filters and diodes into a single chip reduces system size and complexity, contrasting with traditional multi-chip setups. The design is scalable across frequencies from 1 GHz-1 THz with minimal modifications, with the system's form factor inversely scaling with frequency. These features make the technology versatile for applications in environmental monitoring, planetary exploration, radar systems, and advanced communication systems.
sensors

Infrasound Sensor Technology
Large aircraft can generate air vortices in their wake, turbulence that can prove hazardous to aircraft that follow too closely. Because wake vortices are invisible, all takeoffs at busy airports are spaced several minutes apart. This separation gives the vortices time to dissipate, even though they only occur 10% of the time, with resulting loss of operational efficiency. Similarly, clear air turbulence is invisible and can also be hazardous to aircraft. By detecting such disturbances through their infrasound emissions, precautions can be taken to avoid them.
Other phenomena can be detected through infrasound, including tornadoes, helicopters on the other side of mountains, underground nuclear explosions and digging tunnels. Through the unique properties of infrasound, many of these can be detected from hundreds of miles away. NASA's infrasound sensor is a highly refined microphone that is capable of detecting acoustic waves from 20 Hz down to dc, the infrasound range. The design is robust and compact, eliminating the bulk and weight found in other technologies. Where most alternative methods are restricted to certain weather conditions and locations,
the NASA sensor filters noise from wind and other sources, allowing its use under any weather or geographic conditions.
sensors

Low Frequency Portable Acoustic Measurement System
Langley has developed various technologies to enable the portable detection system, including:
- 3-inch electret condenser microphone - unprecedented sensitivity of -45 dB/Hz
- compact nonporous windscreen - suitable for replacing spatially demanding soaker hoses in current use
- infrasonic calibrator for field use - piston phone with a test signal of 110 dB at 14Hz.
- laboratory calibration apparatus - to very low frequencies
- vacuum isolation vessel - sufficiently anechoic to permit measurement of background noise in microphones at frequencies down to a few Hz
- mobile source for reference - a Helmholtz resonator that provides pure tone at 19 Hz
The NASA system uses a three-element array in the field to locate sources of infrasound and their direction. This information has been correlated with PIREPs available in real time via the Internet, with 10 examples of good correlation.
Materials and Coatings

Waveguide-based Dielectric and Magnetic Property Measurement
This NASA invention utilizes a simple waveguide-based measurement system to determine the complex dielectric permittivity and magnetic permeability of arbitrary-shaped planetary rock samples. The system operates at L-band frequencies (~1 GHz) and can be extended to P- and S-bands for broader applications. The approach involves placing an arbitrarily-shaped sample inside an open-ended waveguide excited by a coaxial probe, measuring the scattering parameters, and extracting dielectric and magnetic properties through computational modeling and optimization techniques.
A key aspect of this system is its ability to handle non-uniform and irregularly shaped rock samples, enabling the measurement of real-world planetary materials without requiring extensive sample preparation. The methodology includes calibration in an anechoic chamber, computational modeling, and iterative refinement of measured vs. simulated scattering parameters to extract the material properties.
Future advancements will involve expanding measurements to different frequency bands, refining computational models using artificial intelligence, and automatically rotating samples within the waveguide to obtain multiple directional measurements (enhancing precision while reducing test time).
This NASA innovation has been successfully applied to two Martian meteorite samples, yielding values of dielectric permittivity and permeability relevant for Mars radar applications. The system will further be leveraged to build an expansive database of the dielectric properties of planetary soils and rocks to improve radar-based mapping (e.g., subsurface mapping) missions. The invention could also be applied for the non-destructive screening of a variety of samples using radio waves, including biological samples for medical purposes, additive manufacturing feedstock or finished parts, and mining-related rock samples to test for impurities or resources of interest. This NASA invention is at technology readiness level (TRL) 5 (component and/or breadboard validation in relevant environment) and is available for patent licensing.
sensors

Super Resolution 3D Flash LIDAR
This suite of technologies includes a method, algorithms, and computer processing techniques to provide for image photometric correction and resolution enhancement at video rates (30 frames per second). This 3D (2D spatial and range) resolution enhancement uses the spatial and range information contained in each image frame, in conjunction with a sequence of overlapping or persistent images, to simultaneously enhance the spatial resolution and range and photometric accuracies. In other words, the technologies allows for generating an elevation (3D) map of a targeted area (e.g., terrain) with much enhanced resolution by blending consecutive camera image frames. The degree of image resolution enhancement increases with the number of acquired frames.
communications

NanoWire Glass Switch for Radio Frequency
The nanoionic-based switches developed by NASA's Glenn Research Center exploit the properties of some amorphous materials that can incorporate relatively large amounts of metal and behave as solid electrolytes. As with liquid electrolytes found in lead-acid batteries, for example, solid electrolytes consist of mobile ions which undergo oxidation/reduction reactions at the anode and cathode of the system. The ionic conductivity of such a material can be of the same order of magnitude as the electronic conductivity of a semiconductor but without the drawbacks of an electromechanical device.
In the nanoionic switch, ions are formed at an anode and migrate into the solid electrolyte, while electrons are injected from a cathode, thereby causing the growth of metal nanowires through the electrolyte from the cathode to the corresponding anode when a positive DC bias is applied. Once a nanowire has grown sufficiently to form an electrically conductive path between the electrodes, the switch is closed and no electric power is needed to maintain the connection, unlike in a MEMS or semiconductor-based switch. Moreover, the process of making the connection can easily be reversed by applying a negative bias, causing the wires to ungrow and the switch to open. Thus, NASA's state-of-the-art device is a reversible electrochemical switch that can have geometric features as small as nanometers. The process time for making or breaking the connection is very brief -- about a nanosecond. In addition, this nanoionic material can be deposited in such a way to form multilayer control circuits, which has the potential to minimize circuit footprints, reduce overall circuit losses, and provide unprecedented ease of integration.
Aerospace

Vision-based Approach and Landing System (VALS)
The novel Vision-based Approach and Landing System (VALS) provides Advanced Air Mobility (AAM) aircraft with an Alternative Position, Navigation, and Timing (APNT) solution for approach and landing without relying on GPS. VALS operates on multiple images obtained by the aircraft’s video camera as the aircraft performs its descent. In this system, a feature detection technique such as Hough circles and Harris corner detection is used to detect which portions of the image may have landmark features. These image areas are compared with a stored list of known landmarks to determine which features correspond to the known landmarks. The world coordinates of the best matched image landmarks are inputted into a Coplanar Pose from Orthography and Scaling with Iterations (COPOSIT) module to estimate the camera position relative to the landmark points, which yields an estimate of the position and orientation of the aircraft. The estimated aircraft position and orientation are fed into an extended Kalman filter to further refine the estimation of aircraft position, velocity, and orientation. Thus, the aircraft’s position, velocity, and orientation are determined without the use of GPS data or signals. Future work includes feeding the vision-based navigation data into the aircraft’s flight control system to facilitate aircraft landing.