Electrical and Electronics Commons^™

Uwb Precise Indoor Localization System Performance, Limitations And Its Integration, Essam Abdelkadir Elkhouly

Doctoral Dissertations

An indoor localization system that was built at University of Tennessee is extensively studied and improved. The goal of the system is to achieve mm down to sub-mm accuracy/precision.

Sub-sampling is used to alleviate the high sampling rate required for UWB signals. Current commercial direct sampling systems are still too slow or prohibitively expensive for UWB applications. We developed two different sub-sampling techniques, but the two systems suffer numerous shortcomings: low throughput, non-robustness, non-linearity. A third system is introduced that achieve both high accuracy and high through-put. Changes in the detection algorithm and the frame synchronization are developed to accommodate …

Split-Step Approach To Electromagnetic Propagation Through Atmospheric Turbulence Using The Modified Von Karman Spectrum And Planar Apertures, Monish Ranjan Chatterjee, Fathi H.A. Mohamed

Electrical and Computer Engineering Faculty Publications

The impact of atmospheric phase turbulence on Gaussian beam propagation along propagation paths of varying lengths is examined using multiple random phase screens. The work is motivated by research involving generation and encryption of acousto-optic chaos, and the interest in examining propagation of such chaotic waves through atmospheric turbulence. A phase screen technique is used to simulate perturbations to the refractive index of the medium through the propagation path. A power spectral density based on the modified von Karman spectrum model for turbulence is used to describe the random phase behavior of the medium.

In recent work, results for the …

Improved Performance Of Analog And Digital Acousto-Optic Modulation With Feedback Under Profiled Beam Propagation For Secure Communication Using Chaos, Fares S. Almehmadi, Monish Ranjan Chatterjee

Electrical and Computer Engineering Faculty Publications

Using intensity feedback, the closed-loop behavior of an acousto-optic hybrid device under profiled beam propagation has been recently shown to exhibit wider chaotic bands potentially leading to an increase in both the dynamic range and sensitivity to key parameters that characterize the encryption. In this work, a detailed examination is carried out vis-à-vis the robustness of the encryption/decryption process relative to parameter mismatch for both analog and pulse code modulation signals, and bit error rate (BER) curves are used to examine the impact of additive white noise.

The simulations with profiled input beams are shown to produce a stronger encryption …

Lna Integrates Fast Shutdown Function, Chin-Leong Lim

Chin-Leong Lim

To minimize dead time in time domain duplex (TDD) transceiver, reception should ideally commence as soon as transmission ends. However, the low noise amplifier (LNA), which is typically shutdown during transmission to prevent device damage and receiver overload, can exhibit a turn-on delay. In older implementations, the shutdown function is external to the LNA device. So, one way to reduce part count and to miniaturize this class of LNA is to integrate the LNA and shutdown function in a microwave monolithic integrated circuit (MMIC). The integration also allows the shutdown circuit to be connected to the LNA at an optimum …

Hybrid Silicon Mode-Locked Laser With Improved Rf Power By Impedance Matching, Bassem M. Tossoun

Master's Theses

The mode-locked laser diode (MLLD) finds a lot of use in applications such as ultra high-speed data processing and sampling, large-capacity optical fiber communications based on optical time-division multiplexing (OTDM) systems. Integrating mode-locked lasers on silicon makes way for highly integrated silicon based photonic communication devices. The mode-locked laser being used in this thesis was built with Hybrid Silicon technology. This technology, developed by UC Santa Barbara in 2006, introduced the idea of wafer bonding a crystalline III- V layer to a Silicon-on-insulator (SOI) substrate, making integrated lasers in silicon chips possible.

Furthermore, all mode-locked lasers produce phase noise, which …

Modeling Of Power Spectral Density Of Modified Von Karman Atmospheric Phase Turbulence And Acousto-Optic Chaos Using Scattered Intensity Profiles Over Discrete Time Intervals, Monish Ranjan Chatterjee, Fathi H.A. Mohamed

Electrical and Computer Engineering Faculty Publications

In recent research, propagation of plane electromagnetic (EM) waves through a turbulent medium with modified von Karman phase characteristics was modeled and numerically simulated using transverse planar apertures representing narrow phase turbulence along the propagation path.

The case for extended turbulence was also studied by repeating the planar phase screens multiple times over the propagation path and incorporating diffractive effects via a split-step algorithm. The goal of the research reported here is to examine two random phenomena: (a) atmospheric turbulence due to von Karman-type phase fluctuations, and (b) chaos generated in an acousto-optic (A-O) Bragg cell under hybrid feedback. The …

Realization Of Negative Index In Second-Order Dispersive Metamaterials Using Standard Dispersion Models For Electromagnetic Parameters, Tarig A. Algadey, Monish Ranjan Chatterjee

Electrical and Computer Engineering Faculty Publications

In recent work, electromagnetic propagation velocities for plane waves in dispersive metamaterials were calculated assuming frequency dispersion up to the second order. The three velocities were expressed in terms of dispersive coefficients under certain simplifying constraints. Frequency domains were found to exist around resonances where group and phase velocities are in opposition, implying possible negative index behavior.

In this paper, we incorporate in the derived equations physical models (including Debye, Lorentz and Condon) for material dispersion in permittivity, permeability and chirality in order to further examine the consequences of second-order dispersion leading to negative index for practical cases, and also …

Numerical Investigation Of The Nonlinear Dynamics Of A Hybrid Acousto-Optic Bragg Cell With A Variable Feedback Gain, Monish Ranjan Chatterjee, Hao Zhou

Electrical and Computer Engineering Faculty Publications

Since around 1979, the operation of an acousto-optic Bragg cell under positive first-order feedback via amplification and delay in the loop has been studied extensively by several groups [1-3]. In recent work, the analysis of the nonlinear dynamics (NLD) of the system was extended to include bistable maps and Lyapunov exponents, and application of the chaos for signal encryption and decryption for uniform plane waves. The present work originated with the problem of a variable photodetector aperture opening relative to the first-order light. This potentially complex problem is simplified by assuming instead a variable feedback gain ( β ~ (t)), …

Information Encryption, Transmission, And Retrieval Via Chaotic Modulation In A Hybrid Acousto-Optic Bragg Cell Under Profiled Beam Illumination, Monish Ranjan Chatterjee, Fares S. Almehmadi

Electrical and Computer Engineering Faculty Publications

In recent work, the propagation of a profiled optical beam through an open-loop acousto-optic Bragg cell was examined using a transfer function formalism. The device was also studied under closed-loop via intensity feedback, and shown to exhibit more extended chaotic band responses, thereby potentially increasing the dynamic range and parameter sensitivities of any applied signal and the device operation respectively.

In this paper, simple low- to mid-RF signals (periodic waveforms and low BW audio) are transmitted through the closed-loop system and the resulting encryption and recovery at the receiver are examined especially from the perspective of overall robustness of the …

Low Loss Configuration For Integrated Pin-Schottky Limiters, Chin-Leong Lim

Chin-Leong Lim

Compared to the PIN diode limiter, the Schottky-PIN limiter improves receiver protection, but has a higher insertion loss. Low cost, plastic packaged diodes can further worsen the loss. Diode stacking, mesa diode construction, and isolating the Schottky diode with a high-impedance quarter wave line or a directional coupler can reduce loss, but detrimentally raises the limiting threshold and/or adds bulk or cost. The PIN-Schottky limiter’s insertion loss can be improved by integrating the diodes’ parasitic capacitances into a low pass ladder network, but this solution requires the PIN diode to have two anode connections. Recently, the PIN-Schottky limiter was integrated …

Nonlocal And Quantum-Tunneling Contributions To Harmonic Generation In Nanostructures: Electron-Cloud-Screening Effects, Michael Scalora, Maria Antonietta Vincenti, Domenico De Ceglia, Joseph W. Haus

Electrical and Computer Engineering Faculty Publications

Our theoretical examination of second- and third-harmonic generation from metal-based nanostructures predicts that nonlocal and quantum-tunneling phenomena can significantly exceed expectations based solely on local, classical electromagnetism. Mindful that the diameter of typical transition-metal atoms is approximately 3 Å, we adopt a theoretical model that treats nanometer-size features and/or subnanometer-size gaps or spacers by taking into account (i) the limits imposed by atomic size to fulfill the requirements of continuum electrodynamics, (ii) spillage of the nearly free electron cloud into the surrounding vacuum, and (iii) the increased probability of quantum tunneling as objects are placed in close proximity.

Our approach …

Rapid Battery Exchange Safety And Sensing, Ben John Froelich, Isaac Sungjin Kim

Electrical Engineering

The Rapid Battery Exchange system (RBX) swaps batteries in an electric van, allowing almost continuous operation of the vehicle. The RBX system is designed and built by The Cal Poly Electric Vehicle Engineering Club (EVEC). The system includes the exchange ramp, two battery packs, and the electric “G-Van.” While the vehicle drives using one of the battery packs, the other pack charges in the exchange ramp. When the van’s battery depletes, it drives onto the ramp and swaps the dead battery for the charged one, and the process repeats.

The RBX battery pack safety and sensing project divides into two …

Design Improvement For The Smart Dc Wall Plug, Cory Yee, Haoyan Huang

Electrical Engineering

The DC smart wall plug is a subsystem within the Cal Poly DC House Project. The previous version faces challenges supplying DC voltage to meet household appliances’ nominal values. Specifically, it can only output the minimum required voltage for DC appliances to operate, resulting in unwanted power loss. In addition, the maximum output voltage is rated at 15V, which is insufficient to power most DC appliances. This design improvement project incorporates NFC technology as a solution to overcome the power loss and a new buck converter configuration to increase the output voltage range. Additionally, the new design introduces short-circuit and …

Wirelesseeg: Data Aquisition + Handheld Device, Michael Dylan Snowden, Madeline Threatt, Brent Mcferrin, David Platillero, Karsten Solies, Lindsey Hopf

Chancellor’s Honors Program Projects

No abstract provided.

Numerical Examination Of The Nonlinear Dynamics Of A Hybrid Acousto-Optic Bragg Cell With Positive Feedback Under Profiled Beam Propagation, Fares S. Almehmadi, Monish Ranjan Chatterjee

Electrical and Computer Engineering Faculty Publications

In standard weak interaction theory, acousto-optic Bragg analysis typically assumes that the incident light and sound beams are uniform plane waves. Acousto-optic Bragg diffraction with nonuniform profiled input beams is numerically examined under open loop via a transfer function formalism. Unexpected deviations in the first-order diffracted beam from the standard theory are observed for high �� values. These deviations are significant because the corresponding closed-loop system is sensitive to input amplitudes and initial conditions, and the overall impact on the dynamical behavior has not been studied previously in standard analyses. To explore the effect of such nonuniform output profiles on …

Studies In Software-Defined Radio System Implementation, Harold A. Haldren Iii

Senior Honors Theses

Over the past decade, software-defined radios (SDRs) have an increasingly prevalent aspect of wireless communication systems. Different than traditional hardware radios which implement radio protocols using static electrical circuit, SDRs implement significant aspects of physical radio protocol using software programs running on a host processor. Because they use software to implement most of the radio functionality, SDRs are much more easily modified, edited, and upgraded than their hardware-defined counterparts. Consequently, researchers and developers have been developing previously hardware-defined radio systems within software. Thus, communication standards can be tested under different conditions or swapped out entirely by simply changing some code. …

Memristor-Based Neuron Circuit And Method For Applying Learning Algorithm In Spice, Christopher Yakopcic, R. Hasan, T.M. Taha, M. Mclean, D. Palmer

Electrical and Computer Engineering Faculty Publications

The learning of nonlinearly separable functions in cascaded memristor crossbar circuits is described and the feasibility of using them to develop low-power neuromorphic processors is demonstrated. This is the first study evaluating the training of memristor crossbars through SPICE simulations. It is important to capture the alternate current paths and wire resistance inherent in these circuits. The simulations show that neural network learning algorithms are able to train in the presence of alternate current paths and wire resistances. The fact that the approach reduces the area by three times and power by two orders of magnitude compared with the existing …

Numerical Analysis Of First-Order Acousto-Optic Bragg Diffraction Of Profiled Optical Beams Using Open-Loop Transfer Functions, Monish Ranjan Chatterjee, Fares S. Almehmadi

Electrical and Computer Engineering Faculty Publications

In standard acousto-optic Bragg analysis, the incident light and sound beams are assumed to be uniform plane waves (with constant profiles) leading to the results based on standard weak interaction theory. As a follow-up to earlier work dealing with nonuniform incident optical beams, we revisit the problem of Bragg diffraction under nonuniform profiles, and include Gaussian, third-order Hermite–Gaussian, and zeroth-order Bessel profiles in our investigation, along with a few others. The first-order diffracted beam is examined (using a transfer function formalism based on angular spectra) under several parametric limits [such as the Klein–Cook parameter Q, the effective profile width, and …

Investigation Of Profiled Beam Propagation Through A Turbulent Layer And Temporal Statistics Of Diffracted Output For A Modified Von Karman Phase Screen, Monish Ranjan Chatterjee, Fathi H.A. Mohamed

Electrical and Computer Engineering Faculty Publications

Gaussian beam propagation through a turbulent layer has been studied using a split-step methodology. A modified von Karman spectrum (MVKS) model is used to describe the random behavior of the turbulent media. Accordingly, the beam is alternately propagated (i) through a thin Fresnel layer, and hence subjected to diffraction; and (ii) across a thin modified von Karman phase screen which is generated using the power spectral density (PSD) of the random phase obtained via the corresponding PSD of the medium refractive index for MVKS turbulence.

The random phase screen in the transverse plane is generated from the phase PSD by …

Second-Harmonic Double-Resonance Cones In Dispersive Hyperbolic Metamaterials, Domenico De Ceglia, Maria Antonietta Vincenti, Salvatore Campione, Filippo Capolino, Joseph W. Haus, Michael Scalora

Electrical and Computer Engineering Faculty Publications

We study the formation of second-harmonic double-resonance cones in hyperbolic metamaterials. An electric dipole on the surface of the structure induces second-harmonic light to propagate into two distinct volume plasmon-polariton channels: a signal that propagates within its own peculiar resonance cone and a phase-locked signal that is trapped under the pump's resonance cone. Metamaterial dispersion and birefringence induce a large angular divergence between the two volume plasmon polaritons, making these structures suitable for subwavelength second- and higher-harmonic imaging microscopy.

Numerical Inversion And Assessment Of 2d Laplace Transforms Using The Brancik Algorithm And Its Use In 3d Holography, Monish Ranjan Chatterjee, Le Feng

Electrical and Computer Engineering Faculty Publications

An analytic examination of 3D holography under a 90° recording geometry was carried out earlier in which 2D spatial Laplace transforms were introduced in order to develop transfer functions for the scattered outputs under readout [1,2].

Thereby, the resulting reconstructed output was obtained in the 2D Laplace domain whence the spatial information would be found only by performing a 2D Laplace inversion. Laplace inversion in 2D was attempted by testing a prototype function for which the analytic result was known using two known inversion algorithms, viz., the Brancik and the Abate [2]. The results indicated notable differences in the 3D …

Translation Of 'Seasons Of Life: A Panoramic Selection Of Songs By Rabindranath Tagore', Monish Ranjan Chatterjee

Electrical and Computer Engineering Faculty Publications

No abstract provided.

Compact Lna Drives 2.5-Ghz Base Stations, Chin-Leong Lim

Chin-Leong Lim