Search NASA⌕ Search

SEARCH · Search NASA

Results for “antenna sensor”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records

Distributed Wireless Antenna Sensors for Boiler Condition Monitoring

Monitoring the operational conditions of coal-fired boilers is an important task that could bring tremendous benefits, including in-situ process control, real-time health assessment of structural components, improved heat transfer efficiency, reduced downtime, etc. Moreover, in-situ distributed sensing of the boiler conditions would provide large scale in-situ measurement data that will help us gain fundamental understandings of the combustion and heat transfer processes as well as enable the developments of new simulation tools, which could eventually lead to better design and more efficient operation of the boilers. The objectives of this research were to (a) develop wireless passive antenna sensors without electronics; (b) demonstrate multi-modality sensing using a signal antenna sensor; and (c) fabricate the antenna sensor from high-temperature materials. In this project, we have demonstrated that an antenna sensor or sensor array without any electronics can be wirelessly interrogated from a distance. In addition, a low-cost compact wireless sensor interrogator was developed for dynamic interrogation of the passive antenna sensor. We validated that a dual-frequency antenna sensor is capable of simultaneous strain and temperature measurements or temperature and ash accumulation measurements; all parameters are relevant to boiler condition monitoring. By measuring the temperature and ash accumulation height simultaneously, the dielectric constant of the ash as well as its temperature dependency can also be characterized. This capability could lead to potential applications of the antenna sensor for combustion process monitoring based on the ash composition. We also investigated different techniques of fabricating the antenna sensor using high-temperature materials such as alumina substrate and platinum paste and characterized the thermal response of the antenna sensor. A linear relationship between the antenna resonant frequency and the temperature change was validated.

20 FOSSIL-FUELED POWER PLANTS↗

Wireless Interrogation of a High Temperature Antenna Sensor Without Electronics

This paper presents a novel interrogation mechanism for an antenna sensor subjected to high temperatures. In sensor node, an Ultra-wide Band (UWB) microstrip antenna was used as a wireless Tx/Rx transceiver to amplify the reflected interrogation signal from the temperature-sensing element, i.e. the patch antenna-sensor. A microstrip delay line was used to connect the Tx/Rx antenna and the antenna-sensor so that the reflected signal from the sensor node is delayed and can be separated from the background clutter using time-domain (T-D) gating technique. In this paper, the principle of operation of the proposed interrogation mechanism is first discussed, followed by the design and simulations of the sensor node circuitry. Finally, a temperature test was conducted to validate the wireless temperature sensing performance of the antenna sensor.

Tchafa, Franck Mbanya↗

Interference Mitigation Technique Using Active Spaceborne Sensor Antenna in EESS (Active) and Space Research Service (Active) for Use in 500 MHz Bandwidth Near 9.6 GHz

This document presents an interference mitigation technique using the active spaceborne sensor SAR3 antenna in the Earth Exploration-Satellite Service (active) and Space Research Service (active) for use in a 500 MHz bandwidth near 9.6 GHz. The purpose of the document is present antenna designs which offer lower sidelobes and faster rolloff in the sidelobes which in turn mitigates the interference to other services from the EESS (active) and SRS (active) sensors.

wideband SAR modes↗

Far-Field Interrogation of Microstrip Patch Antenna for Temperature Sensing Without Electronics

Temperature sensing without electronics is demonstrated through wireless interrogation of passive antenna-sensors. The sensor node is equipped with an ultra-wide-band microstrip antenna as the transmitting/receiving (Tx/Rx) antenna and a microstrip patch antenna serving as the temperature-sensing element. A microstrip transmission line connecting the Tx/Rx antenna and the antenna-sensor delays the signal reflected from the sensing element and thus separated it from the background clutter. The operation principle of the wireless sensing scheme is first discussed, followed by the design and simulations of the sensor node circuitry. Furthermore, a digital signal processing algorithm that extracts the antenna resonant frequency from the wirelessly received signal is also described. Temperature tests were conducted to validate the performance of the wireless antenna sensor inside an oven.

42 ENGINEERING↗

The state of technology in electromagnetic (RF) sensors (for lightning detection)

A brief overview of the radio-frequency sensors which were applied to the detection, isolation, and/or identification of the transient electromagnetic energy (sferics) radiated from one or more lightning discharges in the atmosphere is presented. Radio frequency (RF) characteristics of lightning discharges, general RF sensor (antenna) characteristics, sensors and systems previously used for sferic detection, electromagnetic pulse sensors are discussed. References containing extensive bibliographies concerning lightning are presented.

Shumpert, T. H.↗

Microstrip patch antenna for simultaneous strain and temperature sensing

A patch antenna, consisting of a radiation patch, a dielectric substrate, and a ground plane, resonates at distinct fundamental frequencies that depend on the substrate dielectric constant and the dimensions of the radiation patch. Since these parameters change with the applied strain and temperature, this study investigates simultaneous strain and temperature sensing using a single antenna that has two fundamental resonant frequencies. The theoretical relationship between the antenna resonant frequency shifts, the temperature, and the applied strain was first established to guide the selection of the dielectric substrate, based on which an antenna sensor with a rectangular radiation patch was designed and fabricated. A tensile test specimen instrumented with the antenna sensor was subjected to thermo-mechanical tests. Experiment results validated the theoretical predictions that the normalized antenna resonant frequency shifts are linearly proportional to the applied strain and temperature changes. As a result, an inverse method was developed to determine the strain and temperature changes from the normalized antenna resonant frequency shifts, yielding measurement uncertainty of 0.4 °C and 17.22 μϵ for temperature and strain measurement, respectively.

01 COAL, LIGNITE, AND PEAT↗

Passive Wireless Sensors for Realtime Temperature and Corrosion Monitoring of Coal Boiler Components Under Flexible Operation (Final Technical Report)

Researchers at West Virginia University (WVU) propose to demonstrate inexpensive wireless, high-temperature sensors for real-time monitoring of the temperature and corrosion of metal components, which are commonly used in coal-fired boilers. This study presents the development of cost-effective wireless high-temperature sensors for real-time temperature and corrosion monitoring in coal-fired boilers' metal components. The focus is on fabricating and evaluating chipless radio-frequency identification (RFID) sensors capable of operating between 25-1300 ºC. Efforts were directed towards designing passive RFID sensor and interrogator antenna with a broad frequency range, optimizing a microstrip patch antenna sensor integrated into a "peel-and-stick" format for efficient application to various metal specimens without altering their geometry. Additionally, this research aimed to assess the sensor responses under accelerated high-temperature conditions, correlating corrosion and cracking mechanisms with sensor data. An investigation of through-wall data acquisition techniques was also planned, facilitating unobtrusive monitoring of sensor responses housed within metal enclosures. Ultimately, this work sought to establish a robust passive wireless sensor system for the continuous health monitoring of metal components in operational settings, thereby contributing to enhanced safety and efficiency in coal-fired power plants.

20 FOSSIL-FUELED POWER PLANTS↗

Grad E x B effects on heavy ions in the magnetosphere

Following a theory briefing on the currents in a plasma of mixed species caused by the motion of charged particles, the paper presents a report on the observations of regions of the magnetosphere in which significant values of grad E (E being the electric field) can be inferred from measurements of E made on board the IMP 6 satellite using two pairs of long (91.5 m and 45.7 m) unfurlable antenna sensors. Electric fields were measured by applying double floating probe techniques to the antenna sensors, and grad E values of up to 1.4/1000 emu were inferred from the fluctuations in E along the orbit. The critical values of grad E for various ions, in a range of magnetic fields are compared, and the difference in the behavior of Ba+ ions which cause Ba+ currents in the subcritical and supercritical regions is discussed. The results show that the electric currents flowing in the E x B direction may cause secondary polarization fields on the barium cloud. The possible significance of these effects to natural geophysical phenomena is also pointed out.

Cole, K. D.↗

Wireless Fluid Level Measuring System

A level-sensing probe positioned in a tank is divided into sections with each section including (i) a fluid-level capacitive sensor disposed along the length thereof, (ii) an inductor electrically coupled to the capacitive sensor, (iii) a sensor antenna positioned for inductive coupling to the inductor, and (iv) an electrical conductor coupled to the sensor antenna. An electrically non-conductive housing accessible from a position outside of the tank houses antennas arrayed in a pattern. Each antenna is electrically coupled to the electrical conductor from a corresponding one of the sections. A magnetic field response recorder has a measurement head with transceiving antennas arrayed therein to correspond to the pattern of the housing's antennas. When a measurement is to be taken, the measurement head is mechanically coupled to the housing so that each housing antenna is substantially aligned with a specific one of the transceiving antennas.

Taylor, Bryant D.↗

Surface accuracy measurement sensor for deployable reflector antennas

The breadboard surface accuracy measurement sensor is an optical angle sensor which provides continuous line of sight position measurements of infrared source targets placed strategically about the antenna surface. Measurements of target coordinates define the surface figure relative to a reference frame on the antenna. Sensor operation, tests and test results to date are described.

Spiers, R. B., Jr.↗

Wireless SAW Sensors Having Integrated Antennas

A wireless surface acoustic wave sensor includes a piezoelectric substrate, a surface acoustic wave device formed on the substrate, and an antenna formed on the substrate. In some embodiments, the antenna is formed on the surface of the substrate using one or more of photolithography, thin film processing, thick film processing, plating, and printing.

Gallagher, Mark↗

An electromagnetic noncontacting sensor for thickness measurement in a dispersive medium

This paper describes a general purpose imaging technology developed by the U.S. Bureau of Mines (USBM) that, when fully implemented, will solve the general problem of 'seeing into the earth.' A first-generation radar coal thickness sensor, the RCTS-1, has been developed and field-tested in both underground and highwall mines. The noncontacting electromagnetic technique uses spatial modulation created by moving a simple sensor antenna in a direction along each axis to be measured while the complex reflection coefficient is measured at multiple frequencies over a two-to-one bandwidth. The antenna motion imparts spatial modulation to the data that enables signal processing to solve the problems of media, target, and antenna dispersion. Knowledge of the dielectric constant of the media is not necessary because the electrical properties of the media are determined automatically along with the distance to the target and thickness of each layer of the target. The sensor was developed as a navigation guidance sensor to accurately detect the coal/noncoal interface required for the USBM computer-assisted mining machine program. Other mining applications include the location of rock fractures, water-filled voids, and abandoned gas wells. These hazards can be detected in advance of the mining operation. This initiating technology is being expanded into a full three-dimensional (3-D) imaging system that will have applications in both the underground and surface environment.

Chufo, Robert L.↗

A Medium Frequency RF Sensor for Detection of Magnetized Quark Nuggets

It is hypothesized that dark matter is composed of particles called quark nuggets, and further that these particles have a permanent magnetic dipole moment. If this hypothesis is true, calculations predict that a magnetized quark nugget (MQN) will oscillate when encountering the Earth's magnetosphere, and emit RF radiation between 30kHz and 30MHz. To support testing this hypothesis, a loop antenna sensor was designed and developed, which is described in this report. This sensor operates between 300kHz and 3MHz and achieves about -11dBfT/vHz sensitivity at 1.5MHz.

42 ENGINEERING↗

Results from the Radio Frequency Mass Gauge Technology Demonstration on the Intuitive Machines Nova-C Lunar Lander

A cryogenic propellant mass gauge known as the Radio Frequency Mass Gauge (RFMG) was integrated into the Intuitive Machines (IM) Nova-C lunar lander and provided an estimate of the liquid oxygen and liquid methane mass in the lander propellant tanks throughout the IM-1 mission, including during microgravity coast phases. An RFMG electronics controller was used to measure and record the spectrum of the RF signal reflected from an antenna sensor in each tank over the frequency range 100 to 1,300 MHz. The RF spectrum of each of the tanks is unique and is sensitive to the index of refraction of the propellants and the spatial distribution of the liquid within the tanks. Electromagnetic simulation software was used to simulate the antenna response spectra for a given tank geometry, fluid properties, and liquid–vapor configurations within the tank. Over 10,000 antenna response simulations were completed for each propellant tank prior to the IM-1 mission and represented various volumetric fill levels and fluid configurations. The simulated spectra served as a database against which measured tank spectra were compared. For analysis, a spectral matching algorithm was used to find the best match between measured and simulated spectra, and the gauged mass was calculated from the most highly correlated fluid mass simulations. RFMG measurements were recorded during tank loading on the launch pad and during translunar coast, lunar orbit insertion, low lunar orbit, powered descent to the lunar surface, and postlanding on the Moon. This paper describes the RF and fluid simulations, the RFMG measurements and analysis of spectral data, the RFMG instrument, and the gauged results throughout all phases of the IM-1 mission.

lunar lander↗

Results from the Radio Frequency Mass Gauge Technology Demonstration on the Intuitive Machines Nova-C Lunar Lander

A cryogenic propellant mass gauge known as the Radio Frequency Mass Gauge (RFMG) was integrated into the Intuitive Machines (IM) Nova-C lunar lander and provided an estimate of the liquid oxygen and liquid methane mass in the lander propellant tanks throughout the IM-1 mission, including during microgravity coast phases. An RFMG electronics controller was used to measure and record the spectrum of the RF signal reflected from an antenna sensor in each tank over the frequency range 100 to 1,300 MHz. The RF spectrum of each of the tanks is unique and is sensitive to the index of refraction of the propellants and the spatial distribution of the liquid within the tanks. Electromagnetic simulation software was used to simulate the antenna response spectra for a given tank geometry, fluid properties, and liquid–vapor configurations within the tank. Over 10,000 antenna response simulations were completed for each propellant tank prior to the IM-1 mission and represented various volumetric fill levels and fluid configurations. The simulated spectra served as a database against which measured tank spectra were compared. For analysis, a spectral matching algorithm was used to find the best match between measured and simulated spectra, and the gauged mass was calculated from the most highly correlated fluid mass simulations. RFMG measurements were recorded during tank loading on the launch pad and during translunar coast, lunar orbit insertion, low lunar orbit, powered descent to the lunar surface, and postlanding on the Moon. This paper describes the RF and fluid simulations, the RFMG measurements and analysis of spectral data, the RFMG instrument, and the gauged results throughout all phases of the IM-1 mission.

lunar lander↗

The Seasat-A Synthetic Aperture Imaging Radar System

The Seasat-A Synthetic Aperture Imaging Radar System is the first radar system of its kind designed for orbital use. The requirement of this system is to generate continuous radar imagery with a 100-km swath with 25 m resolution from an orbital altitude of 800 km. These requirements impose unique system design problems and a description of the implementation will be given. The end to end data system will be described including interactions of the spacecraft, antenna, sensor, telemetry link, and data processor. The synthetic aperture radar system generates a large quantity of data (110 megabits per second) requiring the use of a dedicated data link. The data link selected for use with the synthetic aperture radar is an analog link with stable local oscillator encoding. The problems associated in telemetering the radar information with sufficient fidelity to synthesize an image on the ground will be described as well as the selected solutions to the problems. The interactions between the antenna attitude control system, rotation of the earth and the data processor will be described as well as proposed solutions, both optical and digital, to generate final imagery with the required 25 m resolution.

Jordan, R. L.↗

Simultaneous Strain and Temperature Sensing using a Microstrip Patch Antenna

In this paper, we present simultaneous strain and temperature sensing using a single microstrip patch antenna fabricated on commercial printed circuit board (PCB). Temperature and strain are extracted from the resonant frequencies of the patch antenna as these frequencies are dependent on the dielectric constant of the PCB and the patch dimensions, which are subject to change with applied strain and temperature variations. The principle of operation of the patch antenna is first discussed, followed by the design and fabrication of the instrumented test specimen. Finally, thermal and mechanical tests were conducted to validate the strain and temperature sensing performance of the antenna sensor

TCHAFA, FRANCK MBANYA↗

CRADA Number NFE-18-07342 with Lux Semiconductors, LLC (CRADA Final Report)

Lux Semiconductors is a flexible microelectronics startup developing a new class of Systemon-Foil electronics for rapidly emerging Internet-of-Things (IoT) markets. By leveraging its patent pending breakthrough in thin-film recrystallization, Lux is able to produce highly crystalline and flexible silicon substrates on a thin metal backing. This novel platform allows for high-speed silicon circuitry to be patterned directly into the substrate alongside low-cost printed electronics. The System-on-Foil approach has potential to enable the fabrication and integration of all core IoT functionality, including microprocessors, sensors, antennas, interconnects, and power supplies, required to enable highly durable, low profile, flexible electronics.

42 ENGINEERING↗