Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"notch filter"”.
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Notch filter control of magnetic bearings to improve rotor synchronous response
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1988.
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Time-Varying Autoregressive Model Based Signal Processing with Applications to Interference Rejection in Spread Spectrum Communications
… variation is necessary to form a time-varying filter. This is realized using the TVAR model, which is an autoregressive model whose coefficients are time-varying with the variation modeled as a linear combination of a set of known functions of time. In DSSS communications, when the strength of …
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Increasing the Dynamic Range of Audio THD Measurements Using a Novel Noise and Distortion Canceling Methodology
… a tuned receiver type Spectrum Analyzer with Notch Filter pre-processing, and a digitized Fast Fourier Transform (FFT) using Notch Filter pre-processing. The THD results appear to agree across all methodologies, and across all items of the sample within all methodologies, to within a percent …
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Integrated Filters and Couplers for Next Generation Wireless Tranceivers
… with the aid of a well-designed band-stop filter. The compact narrowband notch filter designed was able to suppress nonlinear distortions very effectively when used before the PA. The notch filter is also integrated in the injection technique for LTE carrier aggregation (CA) with multiple …
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Adaptive techniques in signal processing and connectionist models
… of new methods and the application of adaptive filter theory which are combined to produce a generalised adaptive filter system which may be used to perform such tasks as pattern recognition. Firstly, the relevant background adaptive filter theory is discussed in Chapter 1 and methods and …
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Filtering techniques for mitigating microwave oven interference on 802.11b wireless local area networks
… can be viewed as noise. The first mitigation filter operates in the frequency domain and filters the received signal's Fast Fourier Transform (FFT) sequence by detecting and removing peak sinusoidal components over the flat 3- dB bandwidth of the signal. The second is a Least Mean Square (LMS) …
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Analysis and Design of a DCM SEPIC PFC with Adjustable Output Voltage
… induction cooker is composed by input filter, diode-bridge rectifier, and full bridge or half bridge series resonant circuit (SRC). High frequency magnetic field is induced through the switching action to heat the pan. The power level is usually controlled through pulse frequency …
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Energy efficient ultra-wideband radio transceiver architectures and receiver circuits
… an unmatched LNA and 802.11a switchable notch filter for interference mitigation. A 100 Mbps system demo is implemented to realize a wireless link. In the low rate regime, energy/bit increases because fixed power costs are less effectively amortized over fewer bits/sec. However, by using …
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Terahertz Raman Spectroscopy of Organic Molecules in Plasmonic Nanogaps
… until 2012. Recent advances in laser and notch filter technology have made the THz region accessible to Raman spectroscopy, accelerating the publication of THz Raman studies on a wide array of bulk materials. While THz SERS measurements are likewise possible, progress has been much slower …
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Adaptive Interference Mitigation in GPS Receivers
… to evaluate the effectiveness of the Adaptive Notch Filter (ANF), a precorrelation mitigation technique that can be used to excise Continuous Wave Interference (CWI), hop-frequency and chirp-type interferences from GPS L1 signals. To mitigate unwanted interference, state-of-the-art ANFs …
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Digital control of a multi-channel boundary-conduction-mode boost converter for power-factor-correction applications
… the line current. In this work, an adaptive notch filter which works over a range of line frequencies, is designed to attenuate the feedback of the 2nd harmonic ripple. The notch filter allows the voltage compensator to be designed at a higher bandwidth, thus ensuring fast output-voltage …
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Design a high gain UWB mimo uniplanar monopole antenna with FSS array for metallic object microwave imaging
… oscillate impedance (za) of 50Ω. A meander-line notch filter is loaded on the designed antenna that achieves a high rejection (S11=-1.75 dB) at the band of 3.0 GHz for 5G mid-band. A T-strip is inserted between the two proposed MIMO antennas to improve the isolation. Moreover, the smallest …
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Tunable Filters and Interference Rejection System for Interferer Suppression at RF and Microwave Bands
… integration of high selectivity RF band-pass filters (BPF), or band-stop filters (BSF) is challenging because of limited quality factor (Q) of passive components in integrated circuit (IC) technology [1]. This proposed research achieves the followings: 1. Developing, and demonstrating …
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Current Sharing Method for DC-DC Transformers
… frequency. To lower the switching frequency, a notch filter is introduced into the LLC resonant tank to increase the sensitivity of the conversion gain versus the operating frequency. The design of the multi-element resonant tank is discussed. Depending soly on the resonant tank, the droop …
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Novel ECG analysis with application to atrial fibrillation detection
… Threshold and High/Low pass (STHL) wavelet based filter is used. An Improved Proportionate Normalised Least Mean Square (IPNLMS) adaptive filter is used to the effects of EMG noise and a bandstop notch filter is used to cope with PLI.;The pattern recognition unit comprises feature extraction …
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From the lab to the real world : sources of error in UF6 gas enrichment monitoring
… spectrum is generated using an x-ray tube and a 'notch' filter. In this dissertation, changes that could occur in the detection efficiency and the transmission errors that could result from variations in pipe-wall thickness will be explored. Additional factors that could contribute to errors in …
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Temperature reconstruction and acoustic time of flight determination for boiler furnace exit temperature measurement
… such as threshold detection with bandpass filtering, cross correlation, generalized cross-correlation (GCC) and a new method developed employing variable notch filters with locations and widths based on repetitive frequencies identified in the noise with cross correlation. The performance …
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Aspects of stepped-frequency processing for low-frequency SAR systems
… been investigated to suppress RFI. Of these, the notch filter and the LMS adaptive filter have been implemented and applied on real P-band data obtained from the E-SAR system of the German Aerospace Center (DLR), Oberpfaffenhofen, and on real VHF-band data obtained from the South African SAR …
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Development of a multilevel converter topology for transformer-less connection of renewable energy systems
… renewable energy source to the grid through the filter and isolation transformer. However, the transformer is bulky, generates losses, and is also very costly. Therefore, the term "transformer-less connection" refers to eliminating a step-up transformer from the WECS, while the power conversion …
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Improved Forward Topologies for DC-DC applications with Built-in Input Filter
… input current ripple reduction and an embedded filter, are proposed to enhance the performance of forward converter using the PWM technique. By inserting a capacitor between two primary windings of the TFC, an input current ripple reduction technique is proposed and a forward converter with …