Agency: Department of Defense | Branch: Navy | Program: STTR | Phase: Phase I | Award Amount: 79.93K | Year: 2015
Tracking dynamic components of rotorcraft is crucial to component life assessment and overall fleet management. The Navy is pursuing an effort to collect the component information directly off the aircraft through the use of passive RFID (pRFID) tags and a novel reader/gateway system to communicate with the ground station. Finding an optimum pRFID tag/antenna reader system arrangement without a computer model would require numerous time consuming and labor intensive trial-and-error measurements, involving different positions of reader antenna and tag configurations, which can vary significantly with only a slight change in the relative location, position or orientation of the antenna. A physics-based computational method for pRFID system design is proposed to develop an innovative, simple-to-use, low cost and computationally efficient tool that can maximize the performance and reliability of the onboard pRFID tag/reader antenna system used to track rotorcraft dynamic components in an enclosed multipath metallic rotorcraft environment. During this project, Applied EM proposes to develop the computational tool that is customized for pRFID systems on rotorcraft with a state of the art Graphical User Interface (GUI).
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 99.99K | Year: 2011
Combined with the demands for UASs is the increasing demand for additional electronic systems, payload carrying capacity, and antennas that are required for each electronic/communication system on the platforms. Broadband conformal antennas offer unique solutions to the strict size weight and power requirements for sensors deployed on UAS. Multi-functional conformal antennas can also address the issue of antenna locations that arise from limited real estate. Typical UAV telemetry systems operating at UHF or L-band frequencies usually employ blade and wire antennas on the fuselage and protrude into the air stream. These antennas degrade aerodynamics, increase drag, increase weight, and usually provide less than optimal antenna performance. These problems can be largely eliminated by conformal (and/or embedded) antennas into UAV composite structures. This antenna research will develop; (a) advanced conformal, low profile and wide bandwidth antennas and (b) apply innovative"paint-on"manufacturing methods to apply conformal antenna (and EMI ground plane shielding) designs directly onto the"skin"of flight platforms. These combined technology developments will provide unique solutions by reducing the profile size and weight of UAS antennas and will also address the issue of antenna locations and (real estate) conflicts through the use of EM simulation and modeling. BENEFIT: Improved UAS conformal antennas for satellite communications, sensors, and COMINT and SIGINT mission applications.Innovations developed under this topic will benefit both DoD and commercial programs. Possible uses for these products include commercial aerospace, automotive, and communications industries.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 749.86K | Year: 2010
Currently, two types of antenna configurations are in use with GPS receivers; fixed reception pattern antenna (FRPA) and controlled reception pattern antenna (CRPA). FRPA is a single element antenna and, thus, can not use angle of arrival as a discriminator to suppress interfering signals or jammers. CRPA is an array of antenna elements that can use angle of arrival as a discriminator to reject interference signals and/or jammers. Many DoD platforms use FRPA due to the cost, size and weight issues. Also, a given platform may have many GPS FRPA to support various communication/ radar/ navigation systems on board the platform. Applied EM proposes a thorough performance evaluation of GPS antenna electronics when conventional antennas (GAS-1 CRPA, GAS-1N CRPA, etc.) are replaced with a set of GPS FRPA. The performance evaluation will be carried out under the jamming scenarios of interest for selected FRPA distributions on a UAV. The goal will be to come up a distribution consisting of four FRPA and another distribution of seven FRPA which lead to the best AJ performance. During Phase I, we compared the AJ performance of the many four and seven FRPA distributions with the performance obtained using regular antenna arrays (inter-element spacing of the order of half a wavelength) when the platform was assumed to be an infinite ground plane. In Phase II, the study will be extended to a UAV. The final goal will be build the antenna arrays and demonstrate their AJ performance on a UAV platform. BENEFIT: The proposed solution is based on the development of a practical GPS AJ system for DoD platforms. Our research effort will also focus on implementation techniques with realistic FRPA designs which will help toward commercialization. This technology has applications in many military systems.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 449.98K | Year: 2011
Antenna placement on electrically large aircraft bodies is becoming a critical issue. Use of full-wave solvers to assess the on-platform performance of an antenna or the interaction between two antennas is impractical, both in terms of computing resources required and length of execution time. The next best choice is to use a high-frequency code. To address this issue, Applied EM is developing state of the art UTD (Uniform Theory of Diffraction) code for faceted CAD geometries. Although not as accurate as full-wave codes, high-frequency codes require modest computer resources and are faster than full-wave codes. In a serial mode, however, even these codes can take substantial time to execute depending on platform size and complexity. During this SBIR, Applied EM and its team members are proposing porting of already developed UTD code to both CPU and GPU-based parallel environments for the purpose of greatly accelerating the performance. During Phase I, we identified bottlenecks in current algorithms and also identified existing algorithms that may be problematic in transferring to a parallel environment. During Phase II, we plan to develop a commercial grade GPU based UTD code that will be commercialized.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 149.94K | Year: 2011
It is critical to accurately predict radiation pattern, near fields and co-site coupling associated with antennas installed on electrically large airborne platforms, which can be addressed by asymptotic high frequency techniques such as the uniform geometrical theory of diffraction (UTD). However, innovative improvements are required in the development and application of these techniques due to challenges such as implementation of creeping wave mechanisms on faceted CAD models, identification of multiple order interactions and modeling of material treatments. Applied EM, Inc. developed a UTD based code, uCAST, to predict radiation pattern and coupling of antennas on electrically large aircraft platforms. Based on the experience with the development of this code, Applied EM proposes to enhance accuracy and efficiency of the code by improving its existing capabilities and implementing new capabilities. For this purpose, some benchmark problems that will address special needs of NAVAIR will be generated. Computed data from the uCAST code will be validated for these problems against computed data from a full-wave solver or measured data. Shortcomings of the existing capabilities and important missing interactions will be identified. The code will be enhanced accordingly to yield better accuracy.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 999.84K | Year: 2011
It is critically important to accurately predict radiation pattern, near fields and co-site coupling associated with antennas placed on electrically large airborne platforms, which can be addressed by high frequency techniques such as the uniform geometrical theory of diffraction (UTD). However, innovative improvements are needed for the development and application of these techniques due to challenges such as implementation of creeping wave mechanisms on faceted CAD models, identification of multiple order interactions and modeling of material treatments. Applied EM, Inc. has been developing a UTD based code, uCAST, to predict radiation pattern and coupling of antennas on electrically large aircraft platforms. During Phase I, some benchmark problems that can be specifically used to validate individual ray mechanisms implemented into the uCAST code have been determined. Radiation pattern data has been generated by the uCAST code for these benchmark problems. The data from the uCAST code has been validated against the MLFMM (multi-level fast multi-pole method) data from FEKO commercial software as well as the data from the UTD based NEWAIR code. Shortcomings of the existing capabilities and important missing interactions have been determined. During Phase II, the code will be enhanced based on the findings to yield better accuracy.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 80.00K | Year: 2012
Objective of the proposed research effort is to design, build and test an experimental AJ antenna for GPS receiver and Iridium transceiver functionality and to develop novel signal processing techniques without compromising the AJ suppression capability of either of the two systems. The AJ antenna will have at least four elements and will be approximately four inch in diameter. The individual antenna elements will be designed to receive M-coded GPS signals in L1 and L2 band as well as receive and transmit Iridium communication system signals simultaneously. Since the transmitted signal is much stronger than the received signals, the antenna must provide good isolation to enable the simultaneous reception of weak navigation and communication signals and transmission of strong communication signal. In this project, Applied EM along with its team members will develop a new signal processing algorithm for the antenna electronics (AE) such that the signal processing capability of a given receiver (GPS or Iridium) are not compromised by the presence of the other signals. Size, weight and Power (SWAP) will be considered in the development of antenna and antenna electronics so that the same antenna system can be used for airborne as well as undersea vehicles.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 709.56K | Year: 2010
US Department of Defense is heavily dependent on the Global Positioning System (GPS) for geolocation, navigation, timekeeping and other military operations. Multipath due to the structure (platform on which the GPS receiver is mounted) scattering can degrade the accuracy of GPS measurements (code and carrier phase) by tens of centimeters. For an airborne platform, reflection or diffraction of the satellite signal from wings, tail, stabilizers or any other large appendage of the aircraft fuselage leads to signal multipath, and these multipath cause biases in code and carrier phase measurements. During Phase I, we studied the performance of two novel adaptive weighting algorithms in the presence of platform generated multipaths. The adaptive weighting algorithms are designed for GPS anti-jam antennas (CRPAs) to null the interfering signals without distorting the satellite signals. During Phase II, we will investigate the performance of the two weighting algorithms in simultaneous nulling of the interfering signals and mitigation of the platform generated multipath using realistic platforms of interest to the Navy. The two weighting algorithms use the knowledge of the in situ antenna manifolds to minimize the distortion of the satellite signals. The sensitivity of the two algorithms to errors in antenna manifold will also be investigated.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase II | Award Amount: 749.97K | Year: 2010
Numerical methods have proved to be very successful in low and mid frequency (VHF/UHF) regimes. Although these methods are based on rigorous integral or partial differential equation formulations, they cannot presently solve electrically large problems of EM radiation pattern and coupling prediction associated with antennas on aircraft at higher frequencies (S/X/Ku/Ka bands). On the other hand, asymptotic high frequency (HF) methods, whose accuracy increases with frequency, such as the physical optics (PO) method and its modifications based on the physical theory of diffraction (PTD), require an integration of the surface currents over the lit portion of the platform, so they also do not scale with frequency. At those frequencies uniform geometrical theory of diffraction (UTD) is very efficient and provides a physical picture for antenna radiation mechanisms and EM interactions with the aircraft platform in terms of rays at high frequencies. However, simulation of the platform using UTD so far is accomplished using a combination of canonical objects, limiting the use of codes based on UTD for complex structures such as fight aircraft etc. Applied EM along with its team members successfully demonstrated during Phase II application of UTD for faceted CAD geometries. Applied EM developed an advanced tool, uCAST based on UTD applicable to CAD geometries along with an interface to commercial tools. During Phase II.5, Applied EM will validate uCAST for NAVAIR applications and transition uCAST to NAVAIR programs.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 79.91K | Year: 2012
The objective of this SBIR effort is to develop controlled-impedance ground planes with reduced weight and thickness, and apply them antennas capable of operation at frequencies from 30 MHz to 600MHz without significant impact on aerodynamics, and designed to occupy the smallest practical surface area at the lowest weight practical. Important specifications are vertical polarization in the horizontal plane, the ability to handle 100 Watts of input power at 100 percent duty cycle from a combination of several radio sets operated simultaneously, and a nominal voltage standing wave ratio (VSWR) of 1.5:1 or less (2:1 maximum). The proposed antenna should not require modification of the existing aircraft skin beyond penetrations for fasteners and the antenna feed port. To meet the objective of this Phase I effort and demonstrate the feasibility of an extremely low-profile antenna design for operating from 30 to 600 MHz, we propose a novel approach with almost zero thickness. During Phase I, various antenna configurations will be studied suitable for various applications.