Browse Topic: Antennas
ABSTRACT Localization refers to the process of estimating ones location (and often orientation) within an environment. Ground vehicle automation, which offers the potential for substantial safety and logistical benefits, requires accurate, robust localization. Current localization solutions, including GPS/INS, LIDAR, and image registration, are all inherently limited in adverse conditions. This paper presents a method of localization that is robust to most conditions that hinder existing techniques. MIT Lincoln Laboratory has developed a new class of ground penetrating radar (GPR) with a novel antenna array design that allows mapping of the subsurface domain for the purpose of localization. A vehicle driving through the mapped area uses a novel real-time correlation-based registration algorithm to estimate the location and orientation of the vehicle with respect to the subsurface map. A demonstration system has achieved localization accuracy of 2 cm. We also discuss tracking results
ABSTRACT This paper will discuss a hybrid approach for antenna placement optimization on tactical vehicles. Tactical vehicles tend to have collocated antennas that operate in adjacent frequency bands. It may be required that two antennas operate simultaneously to satisfy a wide range of voice and data capabilities. The current process to optimize the location of antennas on platforms involves longer test times, complicated logistics, high costs, and is usually performed in an uncontrolled environment. In order to optimize the placement location and minimize the cosite interference between these antennas with consideration to the top deck obstructions, it is advantageous to use a hybrid method. The hybrid method presented here is the combination of Electromagnetic (EM) Modeling and Simulation (M&S) and Laboratory Hardware in the Loop (HWIL) testing. This paper presents the benefits of using this hybrid method in the areas of test time reduction, lessening costs, easing logistics, and
ABSTRACT Antennas are critical to providing digital connectivity to our warfighters. Military mobile networks are much more constrained in operation compared to commercial wireless networks. Military vehicles are limited in size, and must support a large number of different radios. Challenges to both the network and the mobile vehicles require antennas to perform to higher standards. Antenna performance tradeoffs are presented, along with a description of antenna integration methods and emerging technologies to solve integration challenges
ABSTRACT Recent advances in spintronics resulted in the development of a new class of radiation-resistant nano-sized microwave devices - spin-torque nano-oscillators (STNO). To use these novel nano-scale devices in wireless communications system as either microwave sources or detectors it is necessary to develop antennas coupled to STNO and providing efficient radiation and reception of microwave radiation. We demonstrate that it is possible to design antennas of a sub-wavelength size that have sufficiently high efficiency to be successfully used in spintronic communication devices. A coplanar antenna has the best performance characteristics, because its impedance could be easily matched with the impedance of nano-scale spintronic devices. We developed prototype spintronic devices with matched coplanar antennas (oscillators and radar detectors) which could be embedded into armor, thereby improving the survivability of the antennas as well as reducing the visual signature of antennas on
Phased array radar technology has been gaining popularity since its initial introduction in the 1960s and is now being used in a variety of applications, from military and defense to civilian sectors and even space exploration. This cutting-edge technology has revolutionized radar systems by offering unparalleled flexibility, precision, and speed. At the heart of phased array radar lies a sophisticated antenna system composed of numerous individual elements, each capable of independently emitting and receiving radio waves. Unlike traditional radar systems that rely on mechanically rotating antennas, phased array radars electronically steer their beams, enabling rapid and precise target acquisition. This breakthrough is made possible by meticulously controlling the phase of radio waves emitted from each antenna element
When an earthquake, flood, or other disaster strikes a region, existing communication infrastructure such as cell phone and radio towers are often damaged or destroyed. Restoring emergency communications as quickly as possible is vital for coordinating rescue and relief efforts
Testing aircraft antennas is challenging since optimal tests are made after antenna installation. Aircraft are often taken to anechoic antenna test facilities which create long lead times, transportation hassle, and very high costs. Portable alternatives exist but often have compromised testing fidelity. Innovators at the NASA Glenn Research Center have developed the PLGRM system, which allows an installed antenna to be characterized in an aircraft hangar. All PLGRM components can be packed onto pallets, shipped, and easily operated
In this paper, in order to obtain the specified communication range, this work provides a novel optimization approach for antenna placement inside a design space of a vehicle is proposed. The design community can undertake antenna design iterations and quickly investigate antenna placement areas with the help of the optimal placement of antenna utilizing computational electromagnetic (CEM) based optimization approach. The design of experiments (DOE) for various antenna positions and orientations was produced using the Taguchi method [5]. To examine the impact of near field E throughout communication range, Quasi-Newtonian gradient technique and high frequency simulation software (HFSS) are employed. Response curves were created from the received near field E in order to examine the mean, large mean, and cost-wise approaches in order to find the antenna's ideal position and orientation for a strong signal across the communication range
Researchers at the University of Birmingham have developed a new type of high-performance “phase shifter” using a liquid gallium alloy — which varies the phase angle of microwave and millimeter-wave radio signals — for use in advanced phase array antenna systems
Researchers have created electrostatic materials that function even with extremely weak ultrasound, heralding the era of permanent implantable electronic devices in biomedicine. Recent research explores implantable medical devices that operate wirelessly, yet finding a safe energy source and protective materials remains challenging. Presently, titanium (Ti) is used due to its biocompatibility and durability. However, radio waves cannot pass through this metal, necessitating a separate antenna for wireless power transmission. Consequently, this enlarges the device size, creating more discomfort for patients
The traditional centralized random access (RA) and data transmission (DT) protocol used to transmit small-sized packets suffers from high signaling overhead and low channel utilization. To cope with that, this paper proposes a novel distributed queuing random access and data transmission protocol based on multiple-input multiple-output (MIMO) technology for intelligent aircraft scenarios. In the RA phase, the collided, successful, and idle states are redefined according to the degree of freedom (DOF) in MIMO to utilize the RA channel effectively. In the DT phase, the optimal number of simultaneously transmitted M2M devices in the data queue is derived by the number of base station’s antennas to enhance throughput and reduce signaling. Results reveal that the proposed protocol can not only improve the efficiency of RA but also increase the throughput and reduce the delay of DT with the aid of DoF in MIMO while reducing the signaling overhead
A team of University of Otago researchers and physicists have demonstrated a new form of antenna, developed with a small glass bulb containing an atomic vapor. The bulb was wired with laser beams and could therefore be placed far from any receiver electronics. Dr. Susi Otto, from the Dodd-Walls Centre for Photonic and Quantum Technologies, led the field testing of the portable atomic radio frequency sensor. Such sensors, that are enabled by atoms in a so-called Rydberg state, can provide superior performance over current antenna technologies as they are highly sensitive, have broad tunability, and small physical size, making them attractive for use in defense and communications
A team of University of Otago researchers and physicists have demonstrated a new form of antenna, developed with a small glass bulb containing an atomic vapor. The bulb was wired with laser beams and could therefore be placed far from any receiver electronics
Recent advances in the operation of advanced CMOS processes for extremely high-speed and high dynamic range analog-to-digital (ADC) and digital-to-analog (DAC) data converters has led to their use in directly sampling microwave and even millimeter wave signals. Typically, in these applications, minimal pre or post-conditioning stages separate the ADCs and DACs from the antenna or, for Active Electronically Steered Arrays (AESA) antenna elements. This results in an extremely compact and flexible system solution and this has enabled a generation of fully digital phased arrays that are capable of being dynamically reconfigured to perform a multitude of functions
Recent advances in the operation of advanced CMOS processes for extremely high-speed and high dynamic range analog-to-digital (ADC) and digital-to-analog (DAC) data converters has led to their use in directly sampling microwave and even millimeter wave signals. Typically, in these applications, minimal pre or post-conditioning stages separate the ADCs and DACs from the antenna or, for Active Electronically Steered Arrays (AESA) antenna elements. This results in an extremely compact and flexible system solution and this has enabled a generation of fully digital phased arrays that are capable of being dynamically reconfigured to perform a multitude of functions
Historically, patch antennas have been used for SmallSat communications. While new antenna technologies are in development, some are not optimized for size, mass, and performance — especially beyond low-Earth orbit (LEO). Engineers at NASA’s Marshall Space Flight Center identified the need for a small form factor antenna to provide high data rate communications for such missions
Synthetic Aperture Radar (SAR) images are a powerful tool for studying the Earth’s surface. They are radar signals generated by an imaging system mounted on a platform such as an aircraft or satellite. As the platform moves, the system emits sequentially high-power electromagnetic waves through its antenna. The waves are then reflected by the Earth’s surface, re-captured by the antenna, and finally processed to create detailed images of the terrain below
Innovators at NASA Johnson Space Center have developed a quarter-wavelength RFID slot antenna that provides polarization diversity and employs dual resonances, but in a form factor that is much smaller than other RFID antennas that provide similar functionality
A new paper on wireless connectivity from researchers at the lab of Dinesh Bharadia, an affiliate of the UC San Diego Qualcomm Institute (QI), introduces a new technique for increasing access to the 5G-and-beyond millimeter wave (mmWave) network
Antennas are used in many industries and products where quality and reliability are crucial. Testing aircraft antennas is challenging since optimal tests are made after antenna installation. Aircraft are often taken to anechoic antenna test facilities which create long lead times, transportation hassle, and very high costs. This makes such testing cost-prohibitive for early R&D work. Portable alternatives exist but often have compromised testing fidelity. Innovators at the NASA Glenn Research Center have developed the PLGRM system, which allows an installed antenna to be characterized in an aircraft hangar. All PLGRM components can be packed onto pallets, shipped, and easily operated
In the late 1970’s and early 1980’s, Jing-Yau Chung along with Joseph Pope published several external General Motors reports on the then novel measurement of sound intensity (SI) using the two-microphone, cross-spectral method. Application of this measurement method was then extended to sound intensity measurements in flow. Through component wind tunnel measurements, it was determined that the intensity of noise sources could be accurately measured up to a level of 15 dB below the sound pressure level generated by flow noise on microphones. An initial application of this method was to the identification of noise sources alongside rolling truck tires. It was then extended to the measurement of the aerodynamic noise generated by protrusions added to automotive vehicle designs. These included items such as outside rearview mirrors, windshield wipers, A-pillar offsets, grille whistles, roof racks, underbodies, and fixed-mast radio antennas. Many of these could be applied on the early full
When astronauts begin to build a permanent base on the Moon, as NASA plans to do in the coming years, they’ll need help. Robots could potentially do the heavy lifting by laying cables, deploying solar panels, erecting communications towers, and building habitats. But if each robot is designed for a specific action or task, a Moon base could become overrun by a zoo of machines, each with its own unique parts and protocols
HUBER+SUHNER (Herisau, Switzerland) has developed the SENCITY Road MULTI antenna, which reportedly enables multiple onboard applications to be hosted in a single antenna. It was designed specifically for commercial vehicles, such as buses, trucks, ambulances, forest harvesters and agricultural machines. The company states that the antenna groups a number of required elements within one low-profile housing, with single-hole mounting and easy cabling feed-through. The company also claims that through the antenna, customers can deploy 4X4 MIMO wireless modules, including the latest cellular frequencies, as well as up to 8X8 MIMO for Wi-Fi applications. https://www.hubersuhner.com/en
This method is used to define the immunity of electric and electronic apparatus and equipment (products) to radiated electromagnetic (EM) energy. This method is based on injecting the calibrated radio frequency currents (voltages) into external conductors and/or internal circuits of the product under test, measuring the strength of the EM field generated by this product and evaluating its immunity to the external EM field on the basis of the data obtained. The method can be utilized only when it is physically possible to connect the injector to the conductors and/or circuits mentioned before. The method allows: Evaluating immunity of the product under test to external EM fields of the strength equal to a normalized one; Calculating the level of external EM field strength at which the given (including maximum permissible) induced currents or voltages are generated in the equipment under test, or solving the “opposite” task; Finding potentially “weak” points of the product design
In-space and planetary surface assembly for human exploration is a challenging domain that encompasses various technological thrusts to support human missions. NASA is developing autonomous assembly agents to build structures like habitats and antennae on the Moon. These modular and reconfigurable Assembler robots will provide robotic assembly of structures, even in locations that prohibit constant human oversight and teleoperation
Rohde & Schwarz's (Munich, Germany) R&S ATS1500C automotive radar test chamber now offers a new temperature test option and a new feed antenna. According to the company, these additional features enable temperature-controlled measurements in a wide range, as well as parallel access to both polarizations, increasing test efficiency and flexibility. The ARC-TEMP temperature test supports a range from −40 °C to +85 °C (−40° to 185° F). The heated or cooled air is provided by an external thermal air stream system that supplies the air to the temperature bubble mounted on the positioner. The new ARC-FX90 universal-feed antenna supports 60 GHz to 90 GHz and includes an orthomode transducer, which reportedly enables parallel access to vertical and horizontal polarizations. For more information, visit http://info.hotims.com/84487-400
Retrieving objects from a pile is a daunting task for a robot as it involves complex reasoning about the pile and objects in it, which presents a steep challenge. MIT researchers previously demonstrated a robotic arm that combines visual information and radio frequency (RF) signals to find hidden objects that were tagged with RFID tags (which reflect signals sent by an antenna). Building off that work, they have now developed a new system that can efficiently retrieve any object buried in a pile. As long as some items in the pile have RFID tags, the target item does not need to be tagged for the system to recover it
Innovators at NASA Johnson Space Center have developed a cost-effective method to create fabric-based circuits and antennas by combining conventional embroidery with automated milling. The technology allows for higher surface conductivity, improved impedance control, expanded design and application potential, and greater choice of materials for optimized performance
On the other side of the U.S. Army’s milestone multi-orbit antenna trials, the government’s modernization initiative took a timely big step toward unprecedented network resiliency just as adversarial threats reach a fever pitch. The Russian invasion in Ukraine has certainly raised the security stakes and intensified the need for simultaneous communications streams over a single platform, to keep connectivity flowing in the event of intentional jamming, cyberattacks, kinetic attacks, interference, and outages
This AIR provides guidance to the EMI test facility on how to check performance of the following types of EMI test equipment: Current probe Line Impedance Stabilization Network (LISN) Directional coupler Attenuator Cable loss Low noise preamplifier Rod antenna base Passive antennas All performance checks can be performed without software. A computer may be required to generate an electronic or hard copy of data. This is not to say that custom software might not be helpful; just that the procedures documented herein specifically eschew the necessity of automated operation
In-space and planetary surface assembly for human exploration is a challenging domain that encompasses various technological thrusts to support human missions. NASA is developing autonomous assembly agents to build structures like habitats and antennae on the Moon. These modular and reconfigurable Assembler robots will provide robotic assembly of structures, even in locations that prohibit constant human oversight and teleoperation
Following significant impacts from COVID-19, the demand for satellite telecommunications services is rebounding to its historical trajectory of strong growth. With this resurgence comes an increasing need to improve the performance and economy of telecommunications satellites
Engineers have added a new capability to electronic microchips: flight. About the size of a grain of sand, the new flying microchip (microflier) does not have a motor or engine. Instead, it catches flight on the wind — much like a maple tree’s propeller seed — and spins like a helicopter through the air toward the ground. The microfliers also can be packed with ultra-miniaturized technology including sensors, power sources, antennas for wireless communication, and embedded memory to store data
Researchers have taken a step toward developing a type of antenna array that could coat an airplane’s wings, function as a skin patch transmitting signals to medical implants, or cover a room as wallpaper that communicates with Internet of Things (IoT) devices
Items per page:
50
1 – 50 of 768