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 68 for “"Combiner"”.
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Designing a beam combiner for faint limiting magnitudes in optical interferometry
… to develop the Free-space Optical multi-apertUre combineR for IntERferometry (FOURIER), a novel, high sensitivity, near-infrared beam combiner intended to be the first generation science beam combiner for the Magdalena Ridge Observatory Interferometer (MROI). FOURIER is a three telescope, J, H and …
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Design and analysis of a quasi-optical beam combiner for the QUBIC CMB interferometer
… thesis I propose a design for the quasi-optical combiner that will perform as required.
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Opto-VLSI-based adaptive optical power splitter/combiner for next generation dynamic optical telecommunication networks
… novel Opto-VLSI-based adaptive optical splitter/combiner for next generation dynamic optical telecommunication networks. The proposed splitter structure enables an input optical power to be split adaptively into a larger number of output fibre ports, through optimized phase holograms driving the …
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Design and Analysis of the Optical Beam Combiner and Corrugated Feed Horns for the QUBIC Instrument
… and, in particular, its quasi-optical beam combiner. Two variations of QUBIC are analysed: the full instrument (FI) and a technological demonstrator (TD). It was decided to develop the smaller optical combiner of the TD in 2015. The justification for and analysis of the TD are also …
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Ultrafast laser fabrication of a K-band integrated optic 2-telescope beam combiner for astronomical interferometry
… K-band 2-telescope integrated optics (IO) beam combiner is designed and fabricated in commercial Infrasil® glass (IG) to update the existing JouFLU beam combiner at the Center for High Angular Resolution Astronomy (CHARA) array. A liquid crystal on silicon phase-only spatial light modulator …
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A 0.78mm² Co-Channel Interference Canceller in 130nm SOI RF CMOS with Novel Passive Phase Shifters and Combiner Circuitry
An increasingly congested frequency spectrum has presented an unfortunate opportunity for two independent radios on the same device to exist co-channel. Currently, co-channel coexistence requires temporal scheduling to prevent co-channel interference from disrupting downlink communications. This …
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NON-LINEAR PSEUDORANDOM BIT GENERATION BY COMBINING BLUM BLUM SHUB AND LINEAR FEEDBACK SHIFT REGISTER SEQUENCES
… are the strengths and weaknesses of this type of combiner? (2) What constraints must be placed on the input parameters to ensure good cryptographic properties of the output sequence? We generated sequences using variations of this combiner. We then evaluated their cryptographic suitability with …
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Advancing the Performance of a Switched-Mode Radio Frequency Power Generation Architecture
… transmission line transformer-based power combiners. A first step is to create a more accurate combiner model at the required operating frequency which better addresses the loss and performance of this transformer structure, including the interaction of transmission line capacitance and the …
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Low loss microwave power combiners/dividers
… the power from these devices is required. N-way combiners/dividers may be used to achieve this. For high output powers these combiners/dividers must have a high combining efficiency. This dissertation describes various power combining techniques and essentially a power combiner/divider that is …
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Performance Evaluation of Equal Gain Diversity Systems In Fading Channels
… probability density function of the diversity combiner output. This problem is further compounded when the diversity paths are correlated. Since spatial, pattern, or polarization diversity implementations at a mobile handset are usually limited to a small diversity order with closely spaced …
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A fully-integrated all-digital outphasing transmitter for wireless communications
… facilitates minimizing the distortion of an RF combiner. It is newly proposed that two distinct digital predistortion algorithms are required for perfect compensation for both PAs and a combiner. All phase calibration values can be adaptively calculated as a function of outphase angle and saved …
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Efficiency improvement in nanometre CMOS outphasing power amplifiers
… outphasing PAs which utilise unisolated power combiners and switched-mode voltage-source PA stages.<br/><br/>Power combiner design is advanced with the creation of two novel three-port coupled coils which allow multiple inductors to be merged into a single compact low-loss structure. Four …
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Techniques for high-efficiency outphasing power amplifiers
… is limited by the efficiency of the output power combiner. This thesis investigates techniques to overcome this efficiency limit while maintaining sufficient linearity. Two techniques are proposed. The first technique is called the outphasing energy recovery amplifier (OPERA), which recovers the …
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Smart Antennas at Handsets for the 3G Wideband CDMA Systems and Adaptive Low-Power Rake Combining Schemes
… called hybrid combining. The proposed hybrid combiner combines diversity combiner and adaptive combiner outputs using maximal ratio combining (MRC). Since these diversity combining and adaptive combining schemes exhibit somewhat opposite and complementary characteristics, the proposed hybrid …
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Quasi-Optical Design and Analysis of a Bolometric Interferometer for Cosmic Microwave Background Radiation Experiments
… in the design and analysis of the optical combiner here at the Department of Experimental Physics in Maynooth University. This thesis describes the analysis techniques used for the characterisation of the operation of the QUBIC instrument. These techniques: TE/TM mode matching, Gaussian …
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Adaptive signal combining and detection in cooperative wireless networks
… channel noise variance was used as weight of the combiner. The proposed method was a receiver with noise estimation filters at each received branch for the noise estimation. The reciprocal of the estimate of the channels noise variance were used as weights of combiner to achieve Wiener’s solution …
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Phase-locked loop, delay-locked loop, and linear decorrelating detector for asynchronous multirate DS-CDMA system
… density functions of the maximum SNR of the SD combiner, the near-far resistance (NFR) of one-shot LDD by Gaussian approximation, and the maximum SNR of the MR combiner for Hybrid SD/MRC LDD are evaluated, and the bit error probability is obtained from these pdfs. The performance of Hybrid …
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BEAM COMBINING OF FIBER LASERS AND VERTICAL EXTERNAL CAVITY SURFACE EMITTING LASERS USING VOLUME BRAGG GRATINGS
… using a holographic gratings based beam combiner, volume Bragg gratings, for combining the high brightness lasers sources. First, we theoretically study the performance of the beam combiners using the coupled wave equations. Then we conduct beam combining experimental demonstrations of …
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Les réactions imino Diels-Alder et les oxydations de Gif [exposant iv]
… en tant que processus d’oxydation. L’avantage de combiner la réaction Diels-Alder et l’oxydation de Giflv constitue une nouvelle direction à notre étude.
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