Browse Topic: Antennas
Space membrane structures, prized for their lightness, affordability, and ability to fold and unfold, hold immense promise for missions like deep space exploration, high-definition Earth observation, and advanced satellite communications. However, these structures are typically large-size, ultra-lightweight, highly flexible, and have very low damping. This leads to complex dynamic behavior featuring significant geometric nonlinearity, strong coupling between rigid and flexible motions, and uncertain parameters. Consequently, creating accurate yet simple mathematical models for designing controllers is exceptionally difficult, and traditional control methods that rely on such models often fall short. To tackle this problem, this study focuses on a membrane antenna spacecraft equipped with cable actuators, aiming to suppress its vibrations during attitude maneuvers. Using the Deep Deterministic Policy Gradient (DDPG) algorithm, an intelligent vibration controller based on the Actor-Critic architecture is designed. This approach is data-driven, meaning it learns effective control strategies directly through interaction with the system’s environment, bypassing the need for a precise pre-defined mathematical model. Simulation results show that the controller demonstrated superior vibration suppression and strong adaptability across several key scenarios.
To satisfy the real-time beam tracking requirement of low earth orbit (LEO) satellite ground terminals under highly dynamic pass conditions, this paper proposes a three-state hierarchical state-machine beam-control algorithm for liquid crystal phased array antennas (LCPAs). The tracking process is divided into three stages. S1 coarse nine-point acquisition is used to rapidly cover a wide pointing-uncertainty region. S2 fine nine-point refinement introduces quadratic-surface fitting to obtain local peak estimation at sub-step resolution. S3 predictive tracking adopts an interacting multiple model Kalman filter (IMM-KF) based on the constant-acceleration (CA) model and the Singer model, and designs an adaptive covariance regulation mechanism for both measurement and process noise. Combined with explicit delay compensation for liquid-crystal response time, the method suppresses pointing lag and error accumulation in high-dynamic intervals. A dual-threshold hysteretic loss-of-lock criterion and a filter-reset mechanism are also integrated to guarantee autonomous link recovery. Simulation results show that, in an LEO pass scenario with a maximum angular rate of about 2 °/s, the proposed method reduces the median 2D RMSE by about 52%, reduces the 90% quantile error by about 54%, and lowers the median average power loss from 0.14 dB to 0.03 dB compared with the traditional scheme.
Modern space exploration relies more and more on vehicles that carry expansive antenna arrays, a trend driven by steady progress in the field of space engineering. The study centers on constructing a coupled model that accounts for structural rigidity, flexibility, and thermal effects in a sizable orbital unfurling parabolic antenna, along with designing its orientation regulation system. A blended coordinate formulation and a heat-based discretization approach are employed to derive the motion and temperature-governing equations of the assembly. A unified pointing control method is then developed by merging classical feedback control principles with torque compensation control. Computational experiments involving a spacecraft fitted with such a dish antenna are executed. The findings reveal that sudden heat fluctuations, exemplified by the transition out of Earth’s umbra, trigger oscillatory behavior in the antenna framework and disrupt the satellite’s angular position. The designed orientation regulator successfully counteracts these thermally driven perturbations, even when the system representation contains inaccuracies.
This prototype array uses a small, lightweight, low-power, and low-cost aperture. Massachusetts Institute of Technology Lincoln Laboratory, Lexington, MA Preventing adversaries from interfering with communications is crucial to national security. Tactical satellite communications (SATCOM) focus on securing reliable communications channels against adversaries in contested environments. In support of this mission, a team from MIT Lincoln Laboratory is building a prototype antenna characterized by low size, weight, power, and cost (SWaP-C). Threats in contested environments - specifically proliferated low-Earth orbit (pLEO), where satellites must be as low-SWaP as possible because of the high volume of satellites present - are signal jamming and signals intelligence. Mitigating these threats through methods such as changing the shape of antenna beams in real time so that the ground user's signals can't be interfered with and preparing for future advanced capabilities are key to ensuring that satellites stay in communication with users on the ground.
The evolution of wireless communications and the miniaturization of electrical circuits have fundamentally reshaped our lives and the digital landscape. However, as we push toward higher-frequency communications in an increasingly connected world, engineers face growing challenges from multipath propagation — a phenomenon where the same radio signal reaches receiving antennas through multiple routes, usually with time delays and altered amplitudes. Multipath interference leads to many reliability issues, ranging from “ghosting” in television broadcasts to signal fading in wireless communications.
The U.S. Space Force (USSF) Space Systems Command (SSC) achieved a major milestone during a demonstration event in August, showcasing the Joint Antenna Marketplace (JAM) and successfully transferring the U.S. Naval Research Laboratory’s (NRL) Transmit/Receive Enterprise (TREx) Service from a research and development project into an SSC operational prototype.
Dangling from a weather balloon 80,000 feet above New Mexico, a pair of antennas sticks out from a Styrofoam cooler. From that height, the blackness of space presses against Earth’s blue skies. But the antennas are not captivated by the breathtaking view. Instead, they listen for signals that could make air travel safer.
The U.S. Space Force (USSF) Space Systems Command (SSC) achieved a major milestone during a demonstration event in August, showcasing the Joint Antenna Marketplace (JAM) and successfully transferring the U.S. Naval Research Laboratory's (NRL) Transmit/Receive Enterprise (TREx) Service from a research and development project into an SSC operational prototype. During the demonstration, the team demonstrated the use of commercial antennas for real-time contacts between a Space Development Agency's (SDA) satellite operations center and their Tranche 0 satellites using JAM which leveraged the newly integrated TREx system.
In contemporary society, where Global Navigation Satellite Systems (GNSS) are utilised extensively, their inherent fragility gives rise to potential hazards with respect to the safety of ship navigation. In order to address this issue, the present study focuses on an ASM signal delay measurement system based on software defined radio peripherals. The system comprises two distinct components: a transmitting end and a receiving end. At the transmitting end, a signal generator, a first time-frequency synchronisation device, and a VHF transmitting antenna are employed to transmit ASM signals comprising dual Barker 13 code training sequences. At the receiving end, signals are received via software-defined radio equipment, a second time-frequency synchronisation device, a computing host, and a VHF receiving antenna. Utilising sliding correlation algorithms enables accurate time delay estimation. The present study leverages the high performance and low cost advantages of the universal software-defined radio peripheral USRP, fully utilises the good autocorrelation of ASM signals, effectively improves the accuracy of signal transmission delay measurement, and provides a reliable technical means to ensure the safety of ship navigation. The practical application of this subject is of significant importance, and there are wide prospects for its promotion and application.
Reliable antenna performance is crucial for aircraft communication, navigation, and radar detection systems. However, an aircraft's structure can detune the antenna input impedance and obstruct radiation, creating a range of potential problems from a low-quality experience for passengers who increasingly expect connectivity while in the air, to violating legal requirements around strict compliance standards. Determining appropriate antenna placement during the design phase can reduce risk of costly problems arising during physical testing stages. Engineers traditionally use a variety of CAD and electromagnetic simulation tools to design and analyze antennas. The use of multiple software tools, combined with globally distributed aircraft development teams, can result in challenges related to sharing models, transferring data, and maintaining the associativity of design and simulation results. To address these challenges, aircraft OEMs and suppliers are implementing unified modeling and simulation technology and processes, which enables them to combine their CAD model with multiphysics simulation within a secure, data-managed and collaborative computing environment. By using a common user interface with unified collaboration, data management, and design and simulation tools, development teams can create a virtual twin of the complete system, including the aircraft structure, electronics and antennas.
Reliable antenna performance is crucial for aircraft communication, navigation, and radar detection systems. However, an aircraft’s structure can detune the antenna input impedance and obstruct radiation, creating a range of potential problems from a low-quality experience for passengers who increasingly expect connectivity while in the air, to violating legal requirements around strict compliance standards. Determining appropriate antenna placement during the design phase can reduce risk of costly problems arising during physical testing stages.
Data security remains an issue of the utmost concern in contested environments. Mechanisms such as data encryption, beam-forming antennas, and frequency-hopping radio have emerged to mitigate some of the concerns in radio-frequency (RF) communications, but they do not remove all risk. Consequently, there is still a consistent appetite for alternative solutions. This paper presents a case for the use of the free-space optical (FSO) communications technology ImpLi-Fi as one such alternative. FSO communication is promising because of the ease with which the signal beam may be steered and limited, making detection and interception more difficult than with RF, and ImpLi-Fi in particular is desirable for its exceptional outdoor performance and ease of integration into existing light sources. The paper briefly illustrates the origins of the contested logistics (CL) problem and CL use cases for secure communication channels, before describing the ImpLi-Fi technology in some detail; exploring how its field deployment might look, including a telling example with a handheld transmitter device; and foretelling additional potential areas of application. Throughout the paper, ImpLi-Fi is shown to have remarkably high potential utility in contested logistics and beyond.
As NASA’s Artemis missions build out infrastructure on and around the Moon in the coming years, CubeSats and other small satellites will likely play an important role in a communications network that will enable not only conversation with mission control but also navigation, direct scientific observations, and more, all enabled by an internet-like “LunaNet.” These little satellites are cheap to launch and can form constellations for relaying signals reliably. But their small size makes it hard for them to carry antennas large enough to communicate across vast distances.
The global satellite communications (SATCOM) sector is undergoing profound transformation. Fueled by the rapid growth of low Earth-orbit (LEO) constellations, increased government investment, and heightened demand for secure, high-throughput connectivity, the market is projected to expand from $66.75 billion in 2025 to $103.78 billion by 20291, 2. This momentum reflects a broader realignment of priorities across commercial and defense markets: a shift from reliance on legacy geostationary systems toward agile, resilient networks capable of supporting next-generation missions and applications.
Automotive electrical and electronics manufacturer MTA attended IAA Transportation for the first time, demonstrating its new range of wireless communication technologies for the truck industry. Earlier this year, the company acquired Calearo Antenne S.p.A, a company with a long history of producing antennas, amplifiers and cables. MTA global sales director Davide Bonelli explained to Truck & Off-Highway Engineering how that acquisition complements its business. “From a more strategic point of view, we see the world of antennas as complementary to what MTA does,” he said. “Often MTA products have an antenna as an interface, so this is one reason why we have done the deal. There are also a lot of synergies from an engineering standpoint. Historically, MTA is a company that uses many mechanical parts - plastics, metals - which we are very strong with so we can share them. And there are also some competences from Calearo Antenne that can be transferred to us.”
Imagine you had a dedicated wireless channel for communication that was hundreds of times faster than the Wi-Fi we use today, with hundreds of times more bandwidth. That dream may not be far off thanks to the development of metasurfaces: tiny engineered sheets that can reflect and otherwise direct light in desired ways.
The future of wireless technology - from charging devices to boosting communication signals - relies on the antennas that transmit electromagnetic waves becoming increasingly versatile, durable and easy to manufacture. Researchers at Drexel University and the University of British Columbia believe kirigami, the ancient Japanese art of cutting and folding paper to create intricate three-dimensional designs, could provide a model for manufacturing the next generation of antennas. Recently published in the journal Nature Communications, research from the Drexel-UBC team showed how kirigami - a variation of origami - can transform a single sheet of acetate coated with conductive MXene ink into a flexible 3D microwave antenna whose transmission frequency can be adjusted simply by pulling or squeezing to slightly shift its shape.
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.
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.
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.
Researchers from Stanford and the American University of Beirut have developed a lightweight, portable antenna that can communicate with satellites and devices on the ground, making it easier to coordinate rescue and relief efforts in disaster-prone areas. Stanford University, Stanford, California 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. Researchers at Stanford University and the American University of Beirut (AUB) have developed a portable antenna that could be quickly deployed in disaster-prone areas or used to set up communications in underdeveloped regions. The antenna, described recently in Nature Communications, packs down to a small size and can easily shift between two configurations to communicate either with satellites or devices on the ground without using additional power.
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.
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.
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.
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.
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