Engineering Commons^™

Integrated Inductors, Mandar Dilip Kavimandan

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Integrated inductors, also called spiral inductors, on-chip inductors, or planarinductors, are inseparable part in radio frequency integrated circuits (RFICs). Increasing growth in RFICs from the past few decades has forced study of these components in greater detail. Apart from IC inductors, there are several components mounted on a chip - namely capacitors, resistors, MOSFETs, diodes etc. It is extremely important to understand the electrical and magnetic behavior of all these components. Electrical behavior of these components is easy to understand. However, the real challenge lies in realizing and predicting the magnetic behavior of components, namely, inductors and capacitors. Capacitors have …

A Novel Accurate Approximation Method Of Lognormal Sum Random Variables, Xue Li

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Sums of lognormal random variables occur in many problems in wireless communications due to large-scale signal shadowing from multiple transmitters. With the emerging of cognitive radio technology, accurate analysis of interferences from multiple primary users and multiple secondary users is required. Such interferences are well modeled by the lognormal sum distribution. The lognormal sum distribution is known to have no close-form and is difficult to compute numerically. Several approximations to the lognormal sum distribution have been proposed and employed in literature. However, these approximation methods are not without their drawbacks. Some widely used approximation methods are not accurate at the …

Costas Pll Loop System For Bpsk Detection, Rajesh Kumar Keregudadhahalli

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A 2GHz carrier recovery Costas Loop based BPSK detector is designed using CMOS 0.18μm technology. The designed BPSK detector consists of single to differential conversion circuit, phase/frequency detector, Voltage Controlled Oscillator, differential to single conversion circuit, first order loop filter and a third multiplier. Different architectures available for each block have been discussed along with the design methodology adopted. The schematics were simulated in analog design environment.

The Costas loop presented in this work can sense both 0° and 180° phases at its input. Thus the Costas loop carrier recovery circuit overcomes the 180° phase ambiguity presented by the conventional …

Fpga Design Of A Hardware Efficient Pipelined Fft Processor, Ryan T. Bone

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Digital receivers involve fast Fourier transform (FFT) computations that require a large amount of arithmetic operations. The implementation of a FFT processor is one of the most challenging parts in the realization of a wideband receiver and its hardware complexity is very high. Hence, kernel function FFT processors have been proposed to meet real-time processing requirements and to reduce hardware complexity by rounding the kernel function to predetermined kernel points so as to eliminate the multipliers and use only shifters and adders or subtractors. Because of the nonlinear nature of this approximation by the rounding errors, spurious responses are generated …

Ici Reduction Methods For Mc-Cdma Systems, Meng Wu

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Multi-carrier code-division multiple-access (MC-CDMA) is an important multiple access candidate for 4G wireless communication system. While MC-CDMA provides high performance and high capacity in frequency selective fading channels, it is very sensitive to the signal distortion, especially the Inter Carrier Interference (ICI). We apply self-cancelation and a frequency transmission paradigm to MC-CDMA system to improve the sytem performance in an ICI rich environment. Furthermore, we combine the frequency transmission paradigm FD-MC-CDMA with ICI cancelation. Also, we apply all these three schemes into non-contiguous OFDM and non-contiguous MC-CDMA systems in simple Cognitive Radio communication environments and present the simulation results. Theoretical …

A Low-Cost Acoustic Array For Detecting And Tracking Multiple Acoustic Targets, Ellen E. Case

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A wide variety of real-world targets emit distinct acoustic signatures that not only distinguish them from one another but also provide spectral separation from background clutter. While acoustic signatures are distinct, they can also be highly variable, even for an individual target, making detection and tracking a challenging problem. This thesis presents a low-cost acoustic array using commercial off-the shelf (COTS) hardware to detect and track multiple small, moving, acoustic targets. It implements a cross-correlation method for calibration, delay-and-sum beamforming, CA-CFAR detection, a discrete Kalman filter for tracking, and nearest neighbor data association. In addition, the array is designed to …

Automotive Battery State-Of-Health Monitoring Methods, Ryan J. Grube

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Effective vehicular power management requires accurate knowledge of battery state, including state-of-charge (SOC) and state-of-health (SOH). An essential functionality of automotive batteries is delivering high power in short periods to crank the engine. A well-known approach to battery SOH monitoring is to infer battery state-of-health from battery impedance or resistance, which is not robust to variation of battery types. The research and development of more reliable battery state-of-health monitoring methods to ensure vehicle start-up ability are presented in this thesis. The methods include a battery cranking voltage based method, a parity-relation based method using battery voltage and cranking current signals, …

An Algorithm For The Detection Of Handguns In Terahertz Images, Andrew J. Lingg

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This paper presents an algorithm for detecting handguns in terahertz images. Terahertz radiation is capable of penetrating certain materials which are opaque atoptical wavelengths, such as clothing, without the harmful effects of ionizing radiation. The approach taken is to segment objects of interest and classify them based on shape. We use a modified version of an active contour algorithm found in the open literature. Modifications include: a pre-processing step that includes clutter filtering and seeding of an initial contour; and a post-processing step that removes clutter pixels from the segmentation. The features used for classification are moment-based and Fourier shape …

Implementation Of Null Conventional Logic In Cots Fpga's, Mohamad Rajgara

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The digital world has been dominated by the growth of synchronous digital design techniques for last few decades. Traditional Boolean logic is symbolically incomplete since it has a separate control logic, time in the form of clock signal which be carefully integrated with the logic design, but with digital clock signal already in the GHz range, this integration is further complicated. One approach to address post GHz digital logic design is to use clockless or asynchronous digital design techniques. In the mid '90s Theaseus Logic Inc. proposed a method to design Asynchronous circuits using Null Convention Logic (NCL).This thesis introduces …

Real-Time Hilbert Transform And Autocorrelation For Digital Wideband Communication Applications, Murthy, Dilip Srinivasa

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Digital wideband receiver plays a key role in communication and radar systems, and it is used detect and analyze wide range of radio frequency (RF) signals. A digital Instantaneous Frequency Measurement (IFM) receiver is designed, where implementation of a real-time architecture of a Hilbert transform and autocorrelation algorithm is presented. Real-time architecture performs continuous monitoring and processing of the incoming signal. Prior to the previous one bit design, the input data fed to the Hilbert transform is 8-bit wide at a clock rate of 320 MHz with the input data rate is increased by a factor of eight, an 8-bit …

Influence Of Voltage Source Pulse Width Modulated Switching And Induction Motor Circuit On Harmonic Current Content, Martin T. Lange

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The purpose of this research is to present analysis of the harmonic content present in the phase current of a three phase induction motor while being powered by a voltage source pulse-width modulated (PWM) variable speed drive (VSD). First, the topology and circuit of the drive, its operational fundamentals and waveform appearance are presented and discussed. Next, the three-phase induction motor circuit model and operational characteristics are discussed. Finally, the harmonic content present in the induction motor phase current is determined by use of the PSPICE model. The ability of the PSICE simulation to determine harmonic content is established. It …

Simultaneous Rf/Eo Tracking And Characterization Of Dismounts, Jason M. Blackaby

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This thesis discusses the fusion of radar frequency(RF) data and electro-optical (EO) data for tracking and characterization of dismounts (i.e., humans). Each of these sensor modalities provides unique information about the location, structure, and movement of a dismount. The person's location is tracked on the 2D ground plane using RF data for range measurements and EO data for angle measurements. Using this information, measurements are made on the structure and dynamic motion (gait) of the person. An imaging approach is used to create spatio-temporal activity maps along with a three-dimensional reconstruction of the dismount.

Intelligent Spectrum Sensor Radio, Omer Mian

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A cognitive radio is a radio with built-in intelligence that makes it able to utilize the radio frequency spectrum more efficiently by adapting to the changing conditions and frequency availability. In this thesis a spectrum sensor radio is designed that detects transmissions in FM band and determine the range of used and unused frequencies within the band. The radio then starts a transmission on a frequency among the available frequencies. This intelligent radio system design is implemented using the Universal Software Radio Peripheral and GNU Radio with a program written in python that uses a number of GNU Radio modules …

Design Of Pulse Output Direct Digital Synthesizer With An Analog Filter Bank, Aditya R. Pothuri

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Over the past two decades frequency synthesizer has progressed from a relatively crystal bank synthesizer to multi-loop phase locked loops. But in recent years direct digital synthesizers (DDS) have witnessed an increase in demand over their analog counterparts. The DDS offers a wide range of advantages over phase locked loops such as high frequency range, fast switching response, and sub-hertz frequency resolution. However, the conventional DDS suffers limitations due to its architecture involving digital-to-analog converter (DAC) and read-only-memory (ROM) with respect to high clock speeds.

The Pulse Output Direct Digital Synthesizer (PODDS) presented in this thesis eliminates the necessity for …

Gps Coarse Acquisition Using The Monobit Fft Algorithm In A Broadband Receiver, John Flynn

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The purpose of this research was to investigate the feasibility of using broadband electronic warfare (EW) receivers for Global Position System (GPS) tracking. These are pulse-oriented receivers, typically with input bandwidths of 1 Ghz or larger, and so by definition do not have the same characteristics and processing of continuous wave (CW) receivers like GPS devices, FM radios, etc. For example, the spectral output of the Fast Fourier Transform (FFT) used in broadband signal processing updates on the frequency of the FFT input sample size, versus a CW receiver which updates on a more continuous basis.

The foundation of this …

Design Of A Cmos Rf Front End Receiver In 0.18Μm Technology, Vishwas Kudur Sastry

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An RF front end receiver system refers to the analog down conversion stages of the wireless communication system. The Digital base-band signals cannot be transmitted directly through wireless channels due to the properties of electromagnetic waves. The baseband signals need to be converted to analog through a digital-to-analog converter (DAC), up converted to higher frequency using an up conversion mixer and then transmitted through the channel. The received signals are down converted to base band frequency and then converted to digital again using the analog to digital converter (ADC). The processes which the analog signal undergoes at the RF front …