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The interim report describes an initial effort to fabricate an Integrated Photonic Circuit (IPC) which provides a means for converting an optical laser signal, that consists of both a narrow-line carrier wavelength and a heterodyned RF signal that are in-phase, to an electrical RF signal that can drive various on-chip components such as an antenna. The IPC would supply a critical missing element for enabling new phased-array radar based on an all-optical architecture. Ge-on-Si technology, the focus of the effort, has specific advantages that are fundamental to nearly all integrated photonic circuits. Its direct energy bandgap, slightly larger than Ge s indirect bandgap, permits band-to-band recombination/generation at an energy that corresponds to light near the standard optical communications wavelength. Ge-on-Si technology, therefore, could enable a host of IPC subcomponents including photodetectors, laser diodes, and enhanced silicon modulators. In addition, such germanium devices can be simply and inexpensively incorporated into a silicon manufacturing process.

Current research in employing pattern recognition techniques in a wireless sensor network (WSN) to detect anomalous or suspicious behavior is limited. The purpose of this research was to determine the feasibility of an accurate tracking and intent assessment system of unknown or foreign radio frequency (RF) emitters in close proximity to and within military installations as a method for physical security. 22 position tracks were collected using a hand-held Global Positioning System (GPS) unit and a training data set from five di erent features was generated for each position track. Each collected position track was individually classified as suspicious or non-suspicious by the leave-one-out-cross-validation (LOOCV) method using four di erent classification methods. The four classification methods used in this research were the linear discriminant function (LDF), the diagonal linear discriminant function (DLDF), the quadratic discriminant function (QDF) and the Mahalanobis distance method. The accuracies and false positive/negative error rates of the four classification methods were compared for di erent assessment system configurations. Additionally, best fit receiver operating characteristic (ROC) curves were generated for each classification method and discussed. The QDF classification method out-performed the other three classification methods. This classification method achieved an accuracy of 95% when it classified the 22 position tracks one at a time. The lowest false positive and false negative rates were 10% and 0%, respectively. The prior probabilities for the non-suspicious and suspicious classes were both set to 50% class for this configuration., The original document contains color images.

A combined-radar transceiver is constructed which enables target ranging in both linear and nonlinear (harmonic) receive modes. The transceiver is constructed using an arbitrary waveform generator as the signal source, a high-speed digitizing oscilloscope as the signal capture device, and commercial off-the-shelf (COTS) components for the radar front-end. A length of Subminiature Version A (SMA) cable terminated in an open circuit simulates a linear radar target; the same cable terminated in an SMA-connectorized radio front-end simulates a nonlinear radar target. A graphical user interface is developed in MATLAB to control the transceiver remotely. Ranging to the target is demonstrated experimentally using radiofrequency pulses, linear chirps, and stepped-frequency waveforms., The original document contains color images.

The question of how a high-power RF pulse may affect a digital system such as a PC or an electronic control unit for a vehicle has become more important as sources of electromagnetic interference proliferate. The task of building a model for such an interaction is extremely challenging, requiring us to incorporate propagation and coupling of the electromagnetic fields, as well as circuit and system level effects. Rather than address this problem in its entirety, we choose to restrict our focus to a simpler system, specifically a microcontroller, and to RF waveforms directly injected into a set of signal lines. In this paper we will describe an integrated experimental and theoretical investigation of RF effects on n 8051-family microcontroller. We will describe our approach and present results from experimental investigations as well as a model for the probability of effect for an RF signal injected into signal lines carrying arbitrary logic pulse trains. Finally, we will describe how our results shed light on the broader problem of predicting the response of a general digital system to a high-power electromagnetic waveform., The original document contains color images.

This report details the research and training outcomes of a prostate cancer postdoctoral training award. The work resulted in technologies for segmentation, cancer detection, and brachytherapy seed detection that take advantage of ultrasound vibroelastography and ultrasound RF signals. In segmentation, we report a fully automatic algorithm that combines B-mode and elastography data within an active shape model approach. For cancer detection, we report the sensitivity of 75.5% for elastography in cancer detection. In brachytherapy seed detection and dosimetry, we showed that the use of raw RF ultrasound signals can result in partial detection of the seed clouds, sufficient for registration to C-arm fluoroscopy for the purpose of dosimetry. The results were published in form of five journal publications and six conference presentations in international journals and conferences. The PI attended nine conferences and meetings during the course of the award., The original document contains color images.

A narrow-band photonic sigma-delta digital antenna is described as a system intended to provide a proof of concept for the use of photonics technology in the sampling of wide-band radio frequency (RF) signals. The ability to sample wide-band RF signals is an important requirement in modern electronic warfare (EW) systems where a determination of the existence of complex and often difficult to detect signals is sought. As an example, the class of signals referred to as low probability of intercept (LPI) is becoming increasingly common-place with the evolution of modern radar and communication systems. The emergence of this class has led to a concomitant demand for receivers that can provide the necessarily high sensitivity to detect these signals thereby enabling their classification in an electronic intelligence (ELINT) database or jamming using electronic attack (EA). The described system is designed to oversample the analog RF signal exciting an antenna at a rate at least 10 times higher than the Nyquist rate relative to the RF signal frequency (that is, twice the RF signal frequency). Numerous aspects of the development of the described concept demonstrator are presented and extended to outline the requirements for progressing the technology to wide-band capability., The original document contains color images.

The widespread use of vehicle-borne improvised explosive devices (VBIEDs) in Iraq and Afghanistan has resulted in large numbers of military and civilian personnel being killed or injured. Consequently, the Joint Non-Lethal Weapons Directorate's (JNLWD) top priority is to identify, investigate, and develop technologies and capabilities to nonlethally stop both vehicles and vessels outside of minimum keep-out ranges (i.e., ranges where the rules of engagement would dictate the use of lethal force) and to mitigate the blast effects from a VBIED. One of these technologies is the multifrequency Radio-Frequency (RF) Vehicle Stopper (RFVS), a high-power microwave (HPM) weapon under development at the Naval Surface Warfare Center, Dahlgren Division (NSWCDD). A prototype RFVS system, designed to meet the mission criteria for fixed-checkpoint protection and compound protection, is slated for completion in FY13. Science and technology (S&T) work continues in parallel to the prototype system's construction to broaden its applicability to include convoy protection and the establishment of a quick safe zone. This article describes the 4-year research effort that resulted in the specification of the RFVS system design., See also ADA556728. Published in the Leading Edge, v7 n4 p86-91, 2012. Special issue on Directed Energy Applications Across Land, Air, and Sea

The employment of small vessels to attack merchant ships and other seafaring units has emerged as a significant threat to international navigation and safe operations on the high seas. Along with swarm tactics, small vessels have been known to carry improvised explosive devices, help smuggle terrorists and weapons, and serve as attack platforms on the water for larger weapons. While kinetic solutions serve as the decisive option, alternative solutions that employ nonlethal means are being explored. The Naval Surface Warfare Center, Dahlgren Division's (NSWCDD's) Directed Energy Warfare Office (DEWO) is evaluating directed-energy (DE) concepts based on high-power microwave (HPM) technology for nonlethal vessel-stopping applications. Nonlethal weapons are defined by the Department of Defense (DoD) as weapons that are explicitly designed and primarily employed so as to incapacitate personnel or materiel while minimizing fatalities, permanent injury to personnel, and undesired damage to property and the environment. Under the direction of the Joint Non-Lethal Weapons Directorate (JNLWD), the DEWO is in the initial stages of a multiyear effort to evaluate DE concepts for nonlethal vessel-stopping applications. It is currently focusing on HPM technology. This technology uses HPM sources to radiate radiofrequency (RF) pulses downrange to interfere with motor-control electronics and significantly impede or stop small-vessel motors with minimal collateral damage. These RF pulses can be generated using different technologies ranging from wideband LC oscillators and microwave tubes (e.g., magnetrons, klystrons, and backward wave oscillators) to emerging solid-state technologies (e.g., nonlinear transmission line and photo-conductive switching). In comparison to kinetic weapons or other nonlethal systems, HPM avoids gross physical destruction to the vessel while, more importantly, providing zero-to-low risk of human injury., See also ADA556728. Published in the Leading Edge, v7 n4 p96-99, 2012. Special issue on Directed Energy Applications Across Land, Air, and Sea

The ability to understand and predict the effects on electronic systems that might result from an intentional electromagnetic interference (EMI) attack is of great importance in defending critical electronic systems against such a threat. In this paper, we focus on predicting the response of a microcontroller to a high-power electromagnetic waveform. We will describe our approach and present results from experimental investigations as well as modeling of the response of different microcontrollers to the direct injection of a radiofrequency signal into clock and signal lines. We will describe how our results shed light on the broader problem of predicting the response of a general digital system to a high-power electromagnetic waveform. Future work will involve investigating the susceptibility of other instructions and other injection sites, as well as extending our approach to the case of free-field illumination., Presented at the International Conference on Electromagnetics in Advanced Applications (ICEAA 2011) held in Torino, Italy, on 12-16 September 2011. Sponsored in part by the Air Force Office of Scientific Research (AFOSR). The original document contains color images.

This paper provides a summary of recent results on a novel multi-platform RF emitter localization technique denoted as Position-Adaptive RF Direction Finding (PADF). This basic PADF formulation is based on the investigation of iterative path-loss based (i.e. path loss exponent) metrics estimates that are measured across multiple platforms in order to robotically/intelligently adapt (i.e. self-adjust) the location of each distributed/cooperative platform. Recent results at the AFRL indicate that this position-adaptive approach shows potential for accurate emitter localization in challenging embedded multipath environments (i.e., urban environments). As part of a general introductory discussion on PADF techniques, this paper provides a summary of our recent results on PADF and includes a discussion on the underlying and enabling concepts that provide potential enhancements in RF localization accuracy in challenging environments. Also, an outline of recent results that incorporate sample approaches to real-time multi-platform data pruning is included as part of a discussion on potential approaches to refining a basic PADF technique in order to integrate and perform distributed self-sensitivity and self-consistency analysis as part of a PADF technique with distributed robotic/intelligent features. The focus of this paper is on the experimental performance analysis of hardware-simulated PADF environments that generate multiple simultaneous mode-adaptive scattering trends. We cite approaches to addressing PADF localization performance challenges in these multi-modal complex laboratory simulated environments via providing analysis of our multimodal experiment design together with analysis of the resulting hardware-simulated PADF data., Presented at SPIE Defense, Security Sensing Conference held 25-29 April 2011 in Orlando Florida. Prepared in collaboration with Louisiana Technical University, Ruston, LA; and University of Dayton, Dayton, OH. The original document contains color images.

This research project studies the generation of high power bursts of solitons/nonlinear oscillations at radio frequencies from nonlinear lumped element transmission lines (NLETLs) where the nonlinear elements are ferroelectric capacitors or metallised tiles of ferroelectric ceramic. This work leads on from an existing programme where nonlinear tuning diodes or varactors have been used in NLETLs to study and model these phenomena. Earlier work in our laboratories has already demonstrated the feasibility of constructing NLETLs using both strontium and barium/strontium titanates to generate soliton bursts at power levels of tens of MW at frequencies up to 50MHz. This project will study the feasibility of increasing this power to 500MW and above at frequencies of 500 MHz. The main difficulty with this technology has been one of coupling the RF soliton burst efficiently into a resistive load. Several ways of addressing this problem have been identified using experimental, low power NLETLs constructed using varactor diodes and also from a comprehensive computer model of the behaviour of such lines. This model has been exhaustively tested by comparison with experimental results. This project draws on these results to move to high voltage NLETLs built mainly using nonlinear ferroelectric ceramics in the form of capacitors or metallised blocks which should be able to deliver high power RF bursts efficiently into resistive loads and antenna's.

In this experiment, the DC voltage output of a magnetic tunneling junction (MTJ) was measured. This was accomplished using both a broadband log periodic antenna and broadband ridge horn antenna as a radio frequency (RF) source. Transmission frequencies ranged from 1 to 6 GHz at varied power levels of 0 to 20 dBm. The signal was received by a coplanar waveguide antenna. A MTJ rectified the RF signal to a DC voltage.

The integration of photonic and electronic components to realize a photonic sigma delta ADC is considered in this thesis. The integration process was broken up into steps. First, the performance of a pair of dual-port Mach-Zehnder interferometers (MZI) modulating a train of narrow high-speed laser pulses from a mode-locked laser was investigated. Various parameters like the half-wave voltage (V ) and insertion loss were verified. Next, the ability of the MZIs to modulate the laser pulses, including the subtraction of two RF signals going into the two RF ports, was investigated. After that, the performance of a high-speed comparator circuit was evaluated. The comparator circuit was implemented using high-speed analog components capable of supporting data rates of up to 50 Gbps. The comparator components have to be tested individually and then integrated to ensure that they are able to amplitude analyze the modulated laser pulses using their respective matching threshold values. Lastly, the performance of the ring resonator, which was fabricated by the University of California Santa Barbara, was investigated. The ring resonator functions as an accumulator in the photonic ADC. In addition, a MATLAB simulation designed previously was used to simulate the behavior of the photonic sigma delta ADC. It was modified to speed up the simulation time and incorporate actual hardware parameters, including the time and amplitude jitter of the mode-locked laser. These laser parameters were characterized using a high-speed sampling oscilloscope. Thus, it was possible to predict the performance of the ADC under adverse effects as well as to show how the various electrical and optical signals appear at different parts of the circuit, which greatly adds to the efficiency of the integration process.

Recently developed Localized Arc Filament Plasma Actuators (LAFPAs) have shown tremendous control authority in high-speed and high Reynolds number flow for mixing enhancement and noise mitigation. Previously, these actuators were powered by a high voltage pulsed DC plasma generator with low energy coupling efficiency of 5-10%. In the present work, a new custom-designed 8-channel pulsed radio frequency (RF) plasma generator has been developed to power up to 8 plasma actuators operated over a wide range of forcing frequencies (up to 50 kHz) and duty cycles (1-50%), and at high energy coupling efficiency (up to 80-85%). This reduces input electrical power requirements by approximately an order of magnitude, down to 12 W per actuator operating at 10% duty cycle. The new pulsed RF plasma generator is scalable to a system with a large number of channels. Performance of pulsed RF plasma actuators used for flow control was studied in a Mach 0.9 circular jet with a Reynolds number of about 623,000 and compared with that of pulsed DC actuators. Eight actuators were distributed uniformly on the perimeter of a 2.54 cm diameter circular nozzle extension. Both types of actuators coupled approximately the same amount of power to the flow, but with drastically different electrical inputs to the power supplies. Particle image velocimetry measurements showed that jet centerline Mach number decay produced by DC and RF actuators operating at the same forcing frequencies and duty cycles is very similar. At a forcing Strouhal number near 0.3, close to the jet column instability frequency, well-organized periodic structures, with similar patterns and dimensions, were generated in the jets forced by both DC and RF actuators. Farfield acoustic measurements demonstrated similar trends in the Overall Sound Pressure Level (OASPL) change produced by both types of actuators, resulting in OASPL reduction up to 1.2- 1.5 dB in both cases., Accepted for publication in Experiments in Fluids. The original document contains color images. Performed in cooperation with the National Academy of Sciences of Belarus, Minsk, Belarus.

Develop electromagnetic propagation models, that perform equally well over land and sea and in the presence of anomalous propagation conditions for both surface and airborne emitters, for use in operational or engineering propagation assessment systems

Biological effects of pulsed-modulated microwave radiation published in the open scientific literature and unclassified technical reports are reviewed. The effects of short exposures to unmodulated microwaves are included for their possible relevance to exposure to high peak power exposures., The original document contains color images.

This document records the decisions of the United States Air Force with regard to the Supplemental Environmental Impact Statement (SEIS) for the continued operation of the Pave PAWS radar at Cape Cod AFS (December 2008) that was prepared to evaluate potential impacts to the human environment of the continued operation of the Solid-State Phased-Array Radar System (SSPARS), also known as PAVE (an Air Force program name) Phased Array Warning System (PAWS), at Cape Cod Air Force Station (AFS), Massachusetts. In making this decision, the information, analysis, and public comments contained in the SEIS were considered, among other relevant factors. This Record of Decision (ROD) has been prepared in accordance with the National Environmental Policy Act (NEPA) and the regulations implementing NEPA promulgated by the President's Council on Environmental Quality (CEQ), specifically Title 40 Code of Federal Regulations (CFR), Part 1505.2, Record of Decision in cases requiring an environmental impact statement (EIS). The SEIS supplements the analysis provided in a Final EIS entitled, "Operation of the PAVE PAWS RADAR System at Otis Air Force Base, Massachusetts," May 1979. The SEIS is based on updated information and recent studies in order to address potential health effects of radiofrequency energy (RFE) from the continued operation of the Pave PAWS radar at Cape Cod AFS., Best copy available.

Millimeter-wave transceivers require a local reference frequency for upconversion from baseband to RF for transmission, or downconversion of received RF signals down to baseband. This reference can also be divided down to a lower frequency for use as the baseband clock signal. Voltage controlled oscillators (VCOs) can provide this local frequency reference either as free-running oscillators or locked to a stable reference using phase locked loops. Typically, VCOs which utilize a resonant tank achieve the best overall performance, and thus are very common in mm-wave applications. The design of CMOS mm-wave VCOs, however, involves a complex set of trade-offs between tuning range, phase noise, DC power consumption, and output power. In many cases, the most important of these metrics are tuning range and phase noise. The tuning range of the VCO must be large enough to cover the desired band of interest taking into account process, voltage, and temperature variations as well as modelling inaccuracies. Phase noise, on the other hand, contributes to the overall noise figure of the transceiver by causing downconversion of noise and any undesired signals located in frequencies adjacent to the desired signal. Both metrics, however, are strongly dependent on the type and quality factor of the resonant tank used, as shown by Leeson's well known equation for the phase noise of an oscillator., Submitted by Cristian Marcu as Research Project to the University of California, Berkeley, in partial satisfaction of Master of Science degree.

The Navy's Target Indicator Experiment (TIE) payload is part of the Air Force Research Laboratory (AFRL)-developed TacSat-2 spacecraft, which is the second in a series of Operationally Responsive Space (ORS) satellites built to experiment with making space-based assets more responsive to the needs of tactical forces. TacSat-2 was launched on 16 December 2006 from NASA's Wallops Flight Facility on a Minotaur 1 launch vehicle. The spacecraft was placed into a 420 km orbit at an inclination of 40 degrees. The NRL TIE payload is designed to perform real-time collection of RF signals from 0.5 to 18.0 GHz using an adaptation of an unmanned air vehicle payload. The TIE payload is also capable of collecting the Automatic Identification System (AIS) signal now required on large ships for maritime safety and security., Published in NRL Review, p243-245, 2008.

In this study, the pulsed UWB TEMF exposures were to a very high average peak electric field amplitude (102.17 + 5.10 kV/m), a very rapid rise time (229.46 + 25.56 ps), a very small pulse width (0.80 + 0.02 ns), and a reasonable experimental exposure duration (a total of 90 minutes pulsed UWB TEMF exposure). This study demonstrates for the first time that pulsed UWB electromagnetic field exposure does not induce p53 mRNA expression, does not effect p53 protein accumulation, has no effect on the transactivation of its target genes, and there is no cell growth arrest or apoptosis. Lack of p53 protein accumulation and absence of transcriptional activation of p53 target genes in response to pulsed UWB electromagnetic field exposure suggest that UWB TEMF exposure does not induce DNA damage, and that this type of radiation might not be a stress factor to the cells.

A spatial and temporal numerical simulation has been carried out of a pulsed (100% modulated), rf inductively coupled plasma discharge in argon, connected to an additional (ballast) diffusion chamber of much larger volume. It is demonstrated that during the active phase, the presence of the large ballast volume has a small impact on the parameters of the plasma in the smaller discharge chamber. In this case the plasma parameters in the discharge chamber can be estimated separately from the diffusion chamber by a standard method using the characteristic ambipolar diffusion time (for example, using a global model). However, during the afterglow phase, the situation is changed significantly. In the afterglow, the densities of charged particles in the discharge chamber become lower than in the large ballast chamber due to more rapid diffusion loss. As a result, the reverse of the active phase situation occurs, namely, the plasma does not flow from the small to the large chamber, but in the opposite direction, from diffusive to discharge volume, and both the plasma density gradient and the self-consistent ambipolar electric field in the small chamber change directions., Prepared in collaboration with the Department of Physics, West Virginia University, Morgantown, WV, and St. Petersburg State University, St. Petersburg, Russia. Published in the Plasma Sources Science and Technology Journal, v16, n4, p697-702, 2007. Uncorrected proof.

Since past investigations have shown that radio frequency (RF) signal transmission in the bore of a railgun can be practical, the feasibility of using time domain reflectometry and well-established transmission line theory is investigated as a means to determine armature position during launch. This report describes the transmission line model of the HEMCL and initial measurements suggesting that such an approach might be used to provide dynamic armature position profiles. However, subsequent continuous wave analyses of RF transmission line measurements shows that the electrical transmission line characteristics of the HEMCL railgun make it unfeasible to use RF time-domain reflectometry to characterize its dynamic behavior. The laminated containment structure enclosing copper rails of the HEMCL form a very lossy, poorly matched transmission line making it impractical to couple the RF signal into it; high RF attenuation diminishes that portion of the signal that it is coupled. Measurements showed that signals below 900 MHz are completely reflected at the 50-ohm/HEMCL-muzzle nterface. A fraction of RF signals at higher frequencies (900-2400 MHz) can be coupled, but will attenuate by 20 dB or more after propagating only a few tens of centimeters., The views, opinions, and/or findings contained in this report are those of the author(s) and should not be considered as an official Department of the Army position, policy, or decision, unless so designated by other documentation. The original document contains color images.

The use of fiber optics is considered herein as a means to distribute Radio Frequency (RF) signals across Printed Circuit Boards (PCB). The use of fiber optics is studied with an emphasis on reducing inter-board Electromagnetic Interference (EMI). High performance RF circuits are especially sensitive to EMI and other Radio Frequency Interference (RFI), resulting in poor circuit to circuit isolation, spurious signals, additional filtering requirements, and increased shielding constraints. Fiber-optic cable has beneficial characteristics of extremely low cross coupling and is not conductive along its length; this equates to tremendous promise as a means for distributing RF signals with limited EM/RFI. The innovative concept is applicable to PCBs which have a level of RF signals traversing near multiple sensitive RF circuits., Prepared in cooperation with NuWaves, Ltd., Middletown, OH.

Previous experiments and research have indicated rectification of modulated electromagnetic interference can cause upset effects in digital electronics. Although RF rectification has been observed in discrete components, only speculation of the most sensitive mechanisms causing RF rectification has been proposed. Through theoretical analysis, experiments, and simulations, the p-n junctions in ESD protection circuits were determined to be very susceptible to rectifying pulse modulated RF signals. Threshold experiments on several logic families of CMOS inverters provided indications to susceptibilities of electronics based on their input ESD protection topology. High frequency port measurements were performed identifying resonances between 500 MHz and 1.5 GHz due to inductances from bonding wires and the voltage dependent junction capacitances of the ESD protection circuits. Parasitic elements have also been determined to help promote additional effects including bias shifts, state changes, RF gain, and undesirable circuit resonances. DC and high frequency parameter extraction techniques were used to build diode and generic inverter models including package parasitics in PSPICE. Models were designed which gave good agreement to measured rectification drive curves, input impedance resonances, output voltage bias shifts, and induced spurious oscillations.

The main theme of the grant has been to study design of input probe signals for robust system identification. We have used these methods for design of pulse sequences in NMR spectroscopy that are robust to inhomogeneity and dispersion in the parameters of the system of interest. We have developed control theoretic methods which allow control of nuclear spins in presence of extreme inhomogeneities. We have shown that these new nonlinear control methods for probe design and system identification are an enabling technology for NMR and MRI in inhomogeneous fields, making mobile NMR and MRI systems practical. Such a system can serve multiple roles in a combat situation including diagnosis of head injury and trauma, detection of explosives and scanning metabolites in the living tissue., The original document contains color images.

The most significant finding occurred after exposure of human 244B lymphoblastoid cells to a high-peak power pulsed ultrawideband transmitted electric field (UWB TEMF) signal, which had given a wide array of largely negative results. The UWB TEMF exposure (average peak power, 100 kV/m; average pulse width, 780 ps) duration was 90 min (intermittent). The UWB TEMF did not cause an alteration in cell cycle distribution, stabilization of the p53 target genes. There was no loss of mitochondrial membrane potential or release of cytochrome C into the cytosol at 6 hr post-exposure (i.e., no apoptosis). However, at 2 hr a number of gene increase and decrease were detected (12,000 gene microarray system). This suggests that the cells were capable of "sensing" the pulsed UWB TEMF. While the induction of the gene transcription factor NF-kB was observed, no evidence was obtained for downstream activity. The UWB TEMF signal may be necessary, but not sufficient to cause coordinated downstream events. FDTD analysis was performed to determine the doses for exposure cells in suspension or surface attached. An unexpected distribution of energy in the medium is described.

We have now developed the laser technology to excite Rydberg atoms in the trap using a pulsed amplified cw laser. With this system we can produce samples with only 10% fluctuation in the number of Rydberg atoms. This stability is crucial in studying the processes of interest, which always involve interactions among Rydberg atoms and are thus non linear, often highly so, in the density. We have developed millimeter (mm) wave techniques to probe and manipulate the cold Rydberg samples. As will be described below we are able to use the high spectral resolution to observe line broadening, and we have been able to change the macroscopic properties of the sample by changing the quantum state of< 10% of the Rydberg atoms. We have not yet done much to control the geometry of the sample, but it is becoming clear that this is an interesting direction to explore.

This paper examines the effects of signal-dependent versus non-signal-dependent errors on the geolocation accuracy that a state-of-the-art system based on Commercial-off-the-Shelf (COTS) equipment can potentially achieve. The results provide a focus for research in improvements of geolocation accuracy. The studies make use of a simulation tool developed by the Intelligence and Information Warfare Directorate (I2WD) at Fort Monmouth, NJ; supported by CACI Technologies, Inc., Eatontown, NJ; and the Research Associates of Syracuse (RAS), Syracuse, NY., See also ADM001736, Proceedings of the Army Science Conference (24th) held in Orlando, FL on 29 Nov-2 Dec 2004. Prepared in cooperation with CACI Technologies, Inc., Eatontown, NJ, and the Research Associates of Syracuse (RAS), Syracuse, NY. The original document contains color images.

The objective of this thesis is to investigate the performance of the orthogonal frequency division multiplexing (OFDM) based IEEE 802.11a wireless local area network (WLAN) standard receiver when the signal is transmitted over a frequency selective, slow fading Nakagami channel in a worst case, pulse-noise jamming environment. The different combinations of modulation type (both binary and non-binary modulation) and convolutional code rate specified by the WLAN standard are examined. Receiver performance with Viterbi soft decision decoding (SDD) is analyzed for additive white Gaussian noise (AWGN) alone as well as for AWGN plus pulse-noise jamming (PNJ). The performance of the IEEE 802.11a WLAN standard receiver is examined both for the scenario in which perfect side information is assumed (optimum receiver) and when it is not (sub-optimum receiver). For the sub-optimum receiver scenario, the receiver performance is examined both when noise-normalization is utilized and when only linear combining is utilized. The analysis indicates that the receiver performance is severely affected by the pulse-noise jamming environment for the linear combining scenario; however, the sub-optimum receiver performance is significantly improved when noise-normalization is implemented. (2 tables, 74 figures, 11 refs.), The original document contains color images.

We took wind tunnel data and were able to demonstrate low speed (below 5 m/sec) flow attachment on a NACA 0015 airfoil using OAUGDP plasma actuators. We were able further to demonstrate that only one actuator was sufficient to produce re-attachment, and that this actuator should be located not at the site of the flow separation bubble, but at the leading edge of the airfoil. The plasma actuators not only re-attached the flow, but also stabilized the downstream flow, reduced vortex formation, and increased the stall angle of the airfoil. During these wind tunnel tests, we also demonstrated peristaltic flow acceleration by polyphase RF signals driving a phased sequence of OAUGDP plasma actuators, and we demonstrated the reversal ofthe peristalticaly-induced flow with the reversal of the phase of the driving RF voltage. We also developed and investigated mechanically and electrically robust paraelectric, peristaltic, and combined paraelectric and peristaltic ceramic plasma actuator panels. Among these was a three-dimensional electrohydrodynamic flow acceleration duct that functions like a Glauert wall jet. The most promising design was the combined paraelectric and peristaltic panel, and the EHD flow acceleration duct, in which peristaltic flow from phased electrodes is given an additional boost by paraclectric momentum addition, with no momentum addition counter to the dominant flow to induce turbulence in the boundary layer. At the end of the contract, the ERD duct produced exit velocities more than 9 meters/second using paraelectric effects alone. We also achieved up to 7 meters/sec by pure peristaltic acceleration. We also found that one or more plasma actuators in series could be modeled as a classical Glauert wall jet in the region outside the plasma where electrohydrodynamic effects are no longer dominant.

Presented at the Annual Review Meeting (1st) for DoD MURI Award F49620-01-1-0436 on June 8, 2002. The original document contains color images.

Project Statement: Evaluate the response/induced voltages on electrical systems due to radiated EM field environments. Focus is on upset or damage of digital systems for fast transient or pulsed CW excitations at GHz frequencies., Presented at the Annual MURI Review Meeting (1st) held in College Park, MD on 8 June 2002. Published in the Proceedings of the Annual MURI Review Meeting (1st), June 2002. The original document contains color images.

The proper design of RF pulses in magnetic resonance imaging has a direct impact on the quality of acquired images. Several techniques have been proposed to obtain the RF pulse envelope given the desired slice profile. Unfortunately, these techniques do not take into account the limitations of practical implementation such as limited amplitude resolution. Moreover, implementing constraints for special RF pulses on most techniques is not possible. In this work, we propose an approach for designing optimal RF under theoretically any constraints. The new technique poses the RF pulse design problem as a combinatorial optimization problem and uses efficient techniques from this area to solve this problem. In particular, an objective function is proposed as the norm of the difference between the desired profile and the one obtained from solving the Bloch equations for the current RF pulse design values. Two global optimization techniques were implemented using genetic algorithms and simulated annealing. The results show a significant improvement over conventional design techniques and suggest the practicality of using of the new technique for clinical use., Presented at Annual International Conference of the IEEE Engineering in Medicine and Biology Society (23rd) held in Istanbul, Turkey on 25-28 Oct 2001. See also ADM001351 for entire conference on CD-ROM. The original document contains color images.

Desperately Needed Developments to Enable Replacement of RF Switches: * Low Insertion Loss, High-Speed Switches * 10 millisecond SONET Switching is Too Slow for Military Applications * <10 microseconds is Typical Requirement (<100 nanoseconds for High POI Appl.) * Narrow Bandwidth (FP), High-Speed Switches Don't Help!! * Low-RIN EDFAs * WDM Requires Multiplexing and Demultiplexing Multiple Channels * EDFAs ALWAYS Degrade Analog Link Performance * EDFA RIN Must be Reduced Below -155 dB/Hz * High Crosstalk Suppression Between WDM Channels (Optical Switches for Tunable lambda-Filtering) * Easy for Narrowband RF Signals (<1 GHz) * Difficult for 18 GHz and Higher Sidebands * Fiber Bragg Gratings are the Only Demonstrated Technology to Achieve >35 dB(sub 0) Crosstalk Suppression for 18 GHz Sidebands * High-Power WDM DFB Arrays * >40 milliWatt/Channel at RIN <-160 dB/Hz, < 1 MHz Linewidth., Presented at the Defense Advanced Research Projects Agency Microsystems Technology Office (DARPA/MTO) Workshop on Wavelength Division Multiplexing (WDM) for Military Platforms held in McLean, VA on 18-19 April 2000. The original document contains color images. Document contains briefing charts.

The GRACE (Gravity Recovery And Climate Experiment) mission is designed to make global, highly accurate measurements of the Earth's gravity field with high spatial resolution. Ancillary GPS occultation measurements are also to be carried out for atmospheric monitoring. In the dual-1-way biased ranging of this mission, the range between two satellites separated by 100 to 200 km in nearly polar, coplanar, circular orbits, is measured to very high precision, to within an additive constant, through the exchange of K- and Ka-band sinusoidal signals. Such biased ranging data, along with GPS L-band range and phase data, can be processed and fit over successive multiday intervals to obtain accurate estimates of the Earth's gravity field. This report approximately models and analyzes this process, from the generation of the RF signals at the two satellites through the extraction of the geopotential. The steps include generation of the transmitted signals, processing the received signals to extract high-rate baseband phase, carrying out a dual-1-way combination of baseband phase to extract high-rate biased range for each band, combining K- and Ka-band ranges to correct for the ionosphere effect, and processing the resulting high-rate biased range values to extract three types of reduced-rate observables: biased range, range rate and range acceleration. The version of dual-1-way biased ranging developed by this report improves upon previous versions in a number of ways: highly accurate satellite-timetag corrections derived from concurrent GPS data, better baseband phase extraction using highly digital processing, highly accurate USO-rate calibration derived from concurrent GPS data, an improved method for extracting high-rate biased range from baseband phase, improved filtering for extracting reduced- rate observables from high-rate biased range, and parallel extraction of three observable types.

The Adjustable Bandwidth Concept (ABC) signal energy detector has been implemented in the Mathwork's MATLAB environment, with a graphical user interface. The ABC algorithm, U.S. patent #5,257,211 can be applied to a variety of digitized signals, including both audio and basebanded RF communications signals. The implementation allows for easy re-configuration of the algorithm through graphical parameter control, which facilitates signal energy detection tests.

A moving target indicating system wherein a pulse source which generates radiofrequency drive pulses at a predetermined pulse repetition frequency is connected to the inputs of a pair of channels. The first channel includes a phase-dispersive litter having a first phase-slope dispersion characteristic, while the second channel has a phase-dispersive filter having a phase-slope dispersion characteristic which is the negative of that of the first filter. A pulse group comprising the output of the first and the second channels is transmitted periodically as each drive pulse is applied. The pulse repetition frequency is sufficiently low that when transmitted, echos of only one pulse of each group are received at a time. Due to the matched or conjugate phase-dispersive characteristics of the filters in the respective channels, the first channel operates in reception upon the reflected pulse originally generated in the second channel and compresses it thus resynthesizing or reconstituting a short duration pulse like the original, while the second channel operates in reception upon the reflected pulse generated in the first channel, compressing it U) reconstitute a short duration pulse like the original. A canceler is switched between the outputs of the first and second channels U) receive the two resulting reconstituted pulses of each group. In the usual application, fixed target information is cancelled out and moving target information is derived for application to a display device., Supersedes PAT-APPL-458 006-82.

An apparatus using nuclear magnetic or quadrupole resonance to detect selected nuclei in a specimen (e.g., specimens containing a class of explosives or narcotics). The apparatus includes a pulsing unit to generate an RF pulse or a train of pseudo-random RF pulses used in stochastic NQR. Each of the pulses has an RF signal reaching a full amplitude within a quarter-cycle (substantially no pulse rise delay) and having_ a recovery delay of less than Q/pi cycles (substantially no recovery delay). The apparatus also includes a transmitter (e.g., a coil) to irradiate the specimen with a train of pseudo-random RF pulses and to detect after each pulse a resonance signal generated by the specimen in response to each corresponding pulse of the train of pseudo- random RF pulses. The pulsing unit has a capacitor con- nected to a DC power source by a first switch and connected to the coil by a second switch. When the first switch is closed, the DC power source charges the capacitor. After the first switch is opened, the capacitor generates the pulses through the closing and opening of the second switch. The second switch disconnects the coil from the capacitor to end a pulse transmission when the voltage across the coil y is at zero, thereby allowing immediate reception and detection of resonance signals., Supersedes PAT-APPL-749 483-96, AD-D018 498.