Dissertations / Theses on the topic 'Wideband'
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Janardhanan, Deepa. "Wideband speech enhancement." Aachen Shaker, 2008. http://d-nb.info/989298310/04.
Full textA, Rahim Mohamad Kamal. "Wideband active antenna." Thesis, University of Birmingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404129.
Full textSmith, Ian Christopher. "Wideband microwave mixers." Thesis, University of Leeds, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328957.
Full textHamid, Mohamad Rijal. "Wideband reconfigurable antennas." Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/1560/.
Full textBorgmann, Moritz. "Noncoherent MIMO wideband communications /." Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17352.
Full textYuan, Xiaolong. "Wideband Sigma-Delta Modulators." Licentiate thesis, KTH, Communication Systems, CoS, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-13212.
Full textSigma-delta modulators (SDM) have come up as an attractive candidatefor analog-to-digital conversion in single chip front ends thanks to the continuousimproving performance. The major disadvantage is the limited bandwidthdue to the need of oversampling. Therefore, extending these convertersto broadband applications requires lowering the oversampling ratio (OSR) inorder. The aim of this thesis is the investigation on the topology and structureof sigma-delta modulators suitable for wideband applications, e.g. wireline orwireless communication system applications having a digital baseband aboutone to ten MHz.It has recently become very popular to feedforward the input signal inwideband sigma-delta modulators, so that the integrators only process quantizationerrors. The advantage being that the actual signal is not distorted byopamp and integrator nonlinearities. An improved feedforward 2-2 cascadedstructure is presented based on unity-gain signal transfer function (STF). Theimproved signal-to-noise-ratio (SNR) is obtained by optimizing zero placementof the noise transfer function (NTF) and adopting multi-bit quantizer.The proposed structure has low distortion across the entire input range.In high order single loop continuous-time (CT) sigma-delta modulator, excessloop delay may cause instability. Previous techniques in compensation ofinternal quantizer and feedback DAC delay are studied especially for the feedforwardstructure. Two alternative low power feedforward continuous-timesigma-delta modulators with excess loop delay compensation are proposed.Simulation based CT modulator synthesis from discrete time topologies isadopted to obtain the loop filter coefficients. Design examples are given toillustrate the proposed structure and synthesis methodology.Continuous time quadrature bandpass sigma-delta modulators (QBSDM)efficiently realize asymmetric noise-shaping due to its complex filtering embeddedin the loops. The effect of different feedback waveforms inside themodulator on the NTF of quadrature sigma-delta modulators is presented.An observation is made that a complex NTF can be realized by implementingthe loop as a cascade of complex integrators with a SCR feedback digital-toanalogconverter (DAC), which is desirable for its lower sensitivity to loopmismatch. The QBSDM design for different bandpass center frequencies relativeto the sampling frequency is illustrated.The last part of the thesis is devoted to the design of a wideband reconfigurablesigma-delta pipelined modulator, which consists of a 2-1-1 cascadedmodulator and a pipelined analog-to-digital convertor (ADC) as a multi-bitquantizer in the last stage. It is scalable for different bandwidth/resolutionapplication. The detail design is presented from system to circuit level. Theprototype chip is fabricated in TSMC 0.25um process and measured on thetest bench. The measurement results show that a SNR over 60dB is obtainedwith a sampling frequency of 70 MHz and an OSR of ten.
Amat, Pascual Ángel José. "Ultra-Wideband Sensor-Communication." Thesis, Norwegian University of Science and Technology, Department of Electronics and Telecommunications, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-8918.
Full textOne of the fundamentals concerns in wireless communications with battery operated terminals is the battery life. Basically there are two ways of reducing power consumption: the algorithms should be simple and efficiently implemented (at least in the wireless terminals), and the transmit power should be limited. In this document is considered discrete time, progressive signal transmission with feedback [ramstad]. For forward Gaussian channel, with an ideal feedback channel, the system performs according to OPTA (Optimal Performance Theoretically Attainable[berger]). In this case, with substantial bandwidth expansion through multiple retransmissions, the power can be lowered to a theoretical minimum. In the case of a non-ideal return channel the results are limited by the feedback channel's signal-to-noise ratio. Going one step forward, a more realistic view of the channel will consider fading due to multiple reflections, especially in indoors scenarios. In this thesis it is discussed how to model the channel fading and how to simulate it from different probability distributions. After, some solutions to avoid, or at least reduce, all the undesirable effects caused by the fading will be proposed. In these solutions, the fading characteristics (power and dynamic range) and the application requirements will play a vary important role in the final system design. Finally, a realistic signal will be tried to be sent in a realistic scenario. This will be audio transmission over fading channels. Then, the results will be compared in general terms to a similar equipment such as generic wireless microphone system.
Abboud, Karim. "Wideband CELP speech coding." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56805.
Full textthe first approach considers the quantization of Liner Predictive Coding (LPC) parameters and uses a three way split vector quantization. Both scalar and vector quantization are initially studied; results show that, with adequate codebook training, the second method generates better results while using a fewer number of bits. Nevertheless, the use of vector quantizers remain highly complex in terms of memory and number of computations. A new quantization scheme, split vector quantization (split VQ), is investigated to overcome this complexity problem. Using a new weighted distance measure as a selection criterion for split VQ, the average spectral distortion is significantly reduced to match the results obtained with scalar quantizers.
The second approach introduces a new pitch predictor with an increased temporal resolution for periodicity. This new technique has the advantage of maintaining the same quality obtained with conventional multiple coefficient predictors at a reduced bit rate. Furthermore, the conventional CELP noise weighting filter is modified to allow more freedom and better accuracy in the modeling of both tilt and formant structures. Throughout this process, different noise weighting schemes are evaluated and the results show that the new filter greatly contributes in solving the problem of high frequency distortion.
The final wideband CELP coder is operational at 11.7 kbits/s and generates a high perceptual quality of the reconstructed speech using the fractional pitch predictor and the new perceptual noise weighting filter.
Blázquez-Fernández, Raúl 1975. "Ultra-wideband digital baseband." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37895.
Full textIncludes bibliographical references (p. 143-152).
The FCC approved the use of Ultra-wideband signals for communication purposes in February 2002 in the band from 3.1GHz to 10.6GHz, effectively opening 7.5GHz of free unlicensed bandwidth. There are two main constraints for the use of this band: a maximum EIRP spectral density of -41.3dBm/MHz and a minimum instantaneous bandwidth of 500MHz. One of the main driving applications of this technology is high data rate communication over short distances. In this thesis two digital baseband receivers for impulse UWB have been designed. The first one was designed for baseband UWB pulses and achieves 193 kbps of wireless communication using impulses of 300 MHz bandwidth and 2% duty cycle, and was part of a system-on-a-chip. The second baseband achieves 100Mbps using impulses of 500 MHz bandwidth in the FCC compliant band, as part of a whole UWB system. Due to its bandwidth the multipath becomes very relevant as the data rate is increased into the range of the hundreds of megabits per second. The current multipath model, used for the development of IEEE standard 802.15.3a is a modified Saleh-Valenzuela model [1] that has a root mean square duration of the impulse response from 5 to 25 ns. The maximum data rate in an UWB system depends on the signal to noise ratio and the multipath.
(cont.) The assessment of the quality of the channel and the exposure of several useful knobs in the baseband to control the complexity of the signal processing implemented allows higher levels of the communication hierarchy to fine-tune the receiver, trading off number of operations and power dissipation with quality of service. It includes a MLSE and a RAKE receiver to compensate for multipath. It has been implemented in 0.18 um CMOS technology using National Semiconductors process. The chip has been demonstrated in a wireless system.
by Raúl Blázquez.
Ph.D.
Adaniya, Hana L. "Wideband active antenna cancellation." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/47896.
Full textIncludes bibliographical references (leaf 91).
There exists a simultaneous transmit and receive antenna system where the transmitted signal is creating wideband interference of the receiver. To resolve this interference problem, the isolation between the transmit antenna and the receive antenna must be increased. This thesis analyzes and discusses various strategies for antenna isolation and demonstrates the feasibility of an adaptive filtering approach on active signal cancellation. The final system design demonstrates that, with a broadband interference source in close proximity to a receiver, it is possible to provide 30 dB of isolation by using active cancellation.
by Hana L. Adaniya.
M.Eng.
Brower, Alfred N. "DIGITAL WIDEBAND RECORDING SYSTEMS." International Foundation for Telemetering, 2001. http://hdl.handle.net/10150/606438.
Full textHistorically, those interested in recording one or more channels with analog content of greater than or equal to 2 MHz, must use an analog recorder. In the last few years, advancements in analog-to-digital converter technology, performance enhancement in Digital Signal Processors (DSPs), and digital recording devices have made cost-effective, wideband recording applications possible through the use of all-digital techniques. This paper has three objectives: 1. It attempts to explain the benefits of a wideband digital recorder over the traditional analog variety. 2. It discusses the key elements of a wideband digital recorder. 3. It presents a realizable 10-channel, 30 Mbit PCM digital recorder solution. 4. It presents a realizable 14-channel, 2 MHz (bandwidth) digital recorder solution.
Neuens, Jim. "Wideband FM Telemetry Application." International Foundation for Telemetering, 1994. http://hdl.handle.net/10150/611726.
Full textA Wideband FM Telemetry System was developed by Veda Incorporated and Boeing Commercial Airplane. This system supports Boeing 777 flight testing and will support future Boeing test efforts. This is an upgrade to the system previously used by Boeing for testing other planes. The design interfaces to the new Boeing Data Acquisition and Analysis systems and provides 15 Megabits per second Telemetry at ranges up to 180 miles. This paper provides details regarding the following design and integration issues: o) RF Transmitter Design o) RF Receivers o) Airborne Antenna o) Ground Based Antenna o) Data Interfaces o) System Performance o) Problems / Solutions
Tan, Edward S. "Hyper-wideband OFDM system." Thesis, Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/55056.
Full textRadnor, Samuel Benjamin Philip. "The ultra-wideband pulse." Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/1312.
Full textSchuster, Ulrich G. "Wireless communication over wideband channels /." Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17565.
Full textStåhl, Magnus. "Ultra-Wideband Power Amplifier Design." Thesis, Linköpings universitet, Institutionen för teknik och naturvetenskap, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-97064.
Full textPlaivech, Prachaya. "Wideband Antenna Over Ground Plane." Thesis, University of Sheffield, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515450.
Full textJanardhanan, Deepa [Verfasser]. "Wideband Speech Enhancement / Deepa Janardhanan." Aachen : Shaker, 2008. http://d-nb.info/1162792663/34.
Full textAli, Wan Khairuddin Wan. "Design of wideband microstrip antennas." Thesis, Cranfield University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266949.
Full textChen, Shuxian. "Ultra wideband gigabit powerline communication." Thesis, Queen Mary, University of London, 2009. http://qmro.qmul.ac.uk/xmlui/handle/123456789/442.
Full textMACEDO, LUIZ HENRIQUE GUIMARAES DE. "MOBILE INDOOR WIDEBAND FREQUENCY SOUNDING." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2002. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=2570@1.
Full textEste trabalho apresenta os resultados de uma sondagem em frequencia do canal indoor de faixa larga em 1,8GHz, onde foram testados alguns ambientes na tentativa de simular a mobilidade de um usuário. A técnica de sondagem é baseada na técnica clássica de varredura em frequencia, onde foi implementado um link óptico ao invés de cabos coaxiais, para permitir um maior range de medidas. A completa análise de dispersão temporal em pequena e larga escala foi extraída de medidas da resposta impulsiva, como retardo médio, espalhamento rms de retardos, banda de coerência e suas variações com a mobilidade. Do conjunto de análises efetuadas dois resultados obtiveram destaque: perfis de potência de retardo com a distância , resultando em uma boa representação dos principais espalhadores do ambiente; e a validação de um limitante teórico da relação entre a banda de coerência e o espalhamento rms de retardos, recentemente proposto por outro autor. Este trabalho apresenta os resultados de uma sondagem em frequencia do canal indoor de faixa larga em 1,8GHz, onde foram testados alguns ambientes na tentativa de simular a mobilidade de um usuário. A técnica de sondagem é baseada na técnica clássica de varredura em frequencia, onde foi implementado um link óptico ao invés de cabos coaxiais, para permitir um maior range de medidas. A completa análise de dispersão temporal em pequena e larga escala foi extraída de medidas da resposta impulsiva, como retardo médio, espalhamento rms de retardos, banda de coerência e suas variações com a mobilidade. Do conjunto de análises efetuadas dois resultados obtiveram destaque: perfis de potência de retardo com a distância , resultando em uma boa representação dos principais espalhadores do ambiente; e a validação de um limitante teórico da relação entre a banda de coerência e o espalhamento rms de retardos, recentemente proposto por outro autor.
The results of a 1.8 GHz indoor wide-band channel souding survey at some typical environments, trying to account for pedestrian subscriber mobility, are presented. The sounding technique has been based on the classical frequency domain one, with an optic link instead of coaxial cables provinding an extended path range. Complete small and large- scale time dispersionanalysis have been derived from the impulse responses measured, like mean delay, rms delay spread, coherence bandwidth and its variations with mobility. From the whole analysis carried out, two main results are worth remarking: the power delay profile variation with distance providing a pictorial representation of the main scattering mechanisms of the environment; and the validation of a lower bound relation between the coherence bandwidth and rms delay spread recently proposed by another author.
Shen, Yuan Ph D. Massachusetts Institute of Technology. "Fundamental limits of wideband localization." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43069.
Full textIncludes bibliographical references (p. 107-112).
Location-awareness is essential for many wireless network applications. However, determining nodes' positions precisely is a challenging task, especially in harsh multipath propagation environments. To address this problem, wide bandwidth signals are envisioned to be used in future localization systems, since such signals can provide accurate range measurements. In this paper, we investigate the localization performance of wideband networks and proposed a performance measure called the squared position error bound (SPEB) to characterize the localization accuracy. We derive the SPEB succinctly by applying the notion of equivalent Fisher information (EFI). The EFI provides insights into the essence of localization problem by unifying the localization information from individual anchors and that from a priori knowledge of the agent's position in a canonical form. We also investigate the use of wideband antenna arrays and the effect of clock asynchronism on the localization accuracy. Our analysis begins with the received waveforms themselves rather than utilizing only signal metrics, such as time-of-arrival and received signal strength, extracted from the waveforms. Our framework exploits all the information inherent in the received waveforms, and therefore the SPEB serves as a fundamental limit of localization accuracy.
by Yuan Shen.
S.M.
Jing, Sheng Ph D. Massachusetts Institute of Technology. "On sounding in wideband channels." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37931.
Full textThesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.
(cont.) This approach provides us with a cohesive framework to consider the relative costs and benefits of allotting energy for sounding versus transmission, and for repeated sounding of a single channel versus sounding of various different channels. In particular, we are able to give both an upper bound and a lower bound on the number of subchannels that should be probed for capacity maximization in terms of the available transmission energy, the available bandwidth and the fading characteristics of the channel. Moreover, the two bounds are so close to each other that they may well be treated as an approximation to the desirable number of subchannels to probe.
For an average-power-constrained wideband fading channel, on the one hand, if the transmitter has perfect knowledge of the fading state over the entire spectrum, the maximum achievable rate (Capacity) is infinite; on the other hand, if the transmitter has no knowledge of the channel's fading state, the capacity is finite. Therefore, the transmitter's knowledge of channel fading states has a great impact on the channel capacity. However, in the low SNR scenario, the energy per degree of freedom does not suffice to provide an accurate measurement of the channel over the entire spectrum in wideband channels. In the presence of feedback, we may garner information at the transmitter about some aspects of the channel quality over certain portion of the spectrum. In this work, we investigate a scheme to capture the effect of such information. We consider channel sounding with a finite amount of energy over a block-fading channel in both time and frequency. The quality of each subchannel is assessed as being the crossover probability in a BSC. In order to characterize a judicious policy for allocating energy to different subchannels in view of establishing their usefulness for transmission, we use a multi-armed bandit approach.
by Sheng Jing.
S.M.
Elo, Mark. "High-Speed Wideband Frequency Synthesis." International Foundation for Telemetering, 2013. http://hdl.handle.net/10150/579675.
Full textLourens, Jako. "A wideband monopole antenna design." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80026.
Full textENGLISH ABSTRACT: The successful operation of a man-pack VHF jamming system requires a compact and efficient antenna operating over a wide bandwidth. The design of such an antenna is the focus of this thesis. The antenna should be of a practical size for a portable system and it must radiate energy efficiently across a frequency bandwidth in excess of a decade. A practical „target‟ specification of such an antenna has been drawn up based on the performance of a commercially available system. Several possible antenna topologies, each with a variety of loading section options, are tested using “Full wave” electromagnetic modelling (FEKO). Each topology/loading-section is numerically optimised for load element values by considering both its gain and reflection coefficient. Results of the „optimally loaded‟ solution for each topology are then compared to each other to arrive at the best overall design. The best result is found to be the traditional monopole whip-type antenna, with four R-L loading sections spread along its length. The simulated results show that the proposed antenna can be expected to meet the target standing wave ratio (SWR) specifications while offering a gain advantage of between 5 and 10 dBi higher than is available commercially. The selected design is constructed and its performance measured.
AFRIKAANSE OPSOMMING: Die suksesvolle werking van ʼn mobiele VHF "jammer‟ benodig ʼn kompakte antenna met ʼn bruikbare benuttingsgraad wat oor ʼn wyeband funksioneer. Die ontwerp van so ʼn antenna is die fokus van hierdie tesis. Die antenna moet kompak genoeg wees om draagbaar te wees en moet ʼn bruikbare benuttingsgraad hê oor ʼn frekwensie-bandwydte van meer as 10:1. ʼn Praktiese spesifikasie is opgestel vir die antenna deur te kyk na die sigblaaie van beskikbare stelsels. “Volgolf” elektromagnetiese modelleringsagteware is daarna gebruik om ʼn parametriese ondersoek te loods van verskillende antennas. Verskillende topologieë is getoets met ʼn verskeidenheid van belaaide seksies waar die topologieë ge-optimaliseer was vir wins en weerkaatskoëffisiënt. Die resultate vir elke optimale oplossing is vergelyk.Opgrond van hierdie resultate is bevind dat die beste topologie die tradisionele monopoolmas "whip-type‟ antenna is met vier RL lading afdelings langs die lengte versprei. Analise word gebruik om te wys dat verwag kan word dat dit aan die aanwins en staande golf verhouding (SGV) spesifikasies sal voldoen met n 10 dB verhoging in aanwins vir n laer SGV. Die geselekteerde ontwerp is gebou en gemeet om te verifieer dat dit aan die spesifikasies voldoen.
Miller, Alexander. "Electronically reconfigurable wideband microwave filters." Thesis, Heriot-Watt University, 2012. http://hdl.handle.net/10399/2580.
Full textYajnanarayana, Vijaya Parampalli. "Ultra Wideband: Communication and Localization." Doctoral thesis, KTH, Signalbehandling, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-197320.
Full textQC 20161205
Burich, Lawrence D. "Digital Wideband Spectral Sensing Receiver." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1345689526.
Full textVarin, Andre Carleton University Dissertation Engineering Electrical. "A wideband microwave surveillance receiver." Ottawa, 1987.
Find full textLangner, Paul (Paul Allen) Carleton University Dissertation Engineering Electrical. "A wideband parallel sampling system." Ottawa, 1990.
Find full textNisbet, John (John Jackson) Carleton University Dissertation Engineering Electrical. "Ultralinear wideband integrated circuit design." Ottawa, 1993.
Find full textSchuster, Ulrich G. "Wireless communication over wideband channels." Konstanz Hartung-Gorre, 2008. http://d-nb.info/993286984/04.
Full textEnchelmaier, David Samuel. "A miniaturised wideband frequency synthesiser." Thesis, Queensland University of Technology, 2009. https://eprints.qut.edu.au/31851/1/David_Enchelmaier_Thesis.pdf.
Full textDo-Hong, Tuan [Verfasser]. "Wideband Direction-of-Arrival Estimation and Wideband Beamforming for Smart Antenna Systems / Tuan Do-Hong." Aachen : Shaker, 2004. http://d-nb.info/1170534392/34.
Full textTu, Yuxiang X. "Design, modelling and implementation of several multi-standard high performance single-wideband and multi-wideband microwave planar filters." Thesis, University of Bradford, 2016. http://hdl.handle.net/10454/15720.
Full textLai, Hau Wah. "Wideband meandering probe-fed patch antenna /." access full-text access abstract and table of contents, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?phd-ee-b19887383a.pdf.
Full text"Submitted to Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves 144-153).
Chen, Tingsu. "Wideband Amplifier Design for STO Technology." Thesis, KTH, Integrerade komponenter och kretsar, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-78198.
Full textLatva-aho, M. (Matti). "Advanced receivers for wideband CDMA systems." Doctoral thesis, University of Oulu, 1998. http://urn.fi/urn:isbn:9514250397.
Full textSmith, Alison M. "A wideband adaptive feedforward amplifier lineariser." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq24241.pdf.
Full textWilson, Jason K. "Maritime surveillance using a wideband hydrophone." Thesis, Monterey, Calif. : Naval Postgraduate School, 2007. http://bosun.nps.edu/uhtbin/hyperion-image.exe/07Sep%5FWilson%5FJason.pdf.
Full textThesis Advisor(s): Rice, Joseph A. ; Kapolka, Daphne ; Hursky, Paul. "September 2007." Description based on title screen as viewed on October 25, 2007. Includes bibliographical references (p. 49). Also available in print.
Kämpe, Andreas. "Voltage controlled oscillators for wideband receivers /." Stockholm : Department of Microelectronics and Information Technology, Royal Institute of Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4083.
Full textOyefuga, Oladipupo Olaseni. "Downlink optimisation for wideband CDMA systems." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414589.
Full textAhmadian, Zahra. "Multiuser pre-filtered ultra-wideband systems." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45592.
Full textZewani, Mohammed. "Low distortion wideband microwave power amplifiers." Thesis, University of Leeds, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.440631.
Full textWilliams, Christopher. "Chaotic synchronisation in wideband communication systems." Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299732.
Full textPowell, Johnna 1980. "Antenna design for ultra wideband radio." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28542.
Full text"May 2004."
Includes bibliographical references (p. 108-109).
The recent allocation of the 3.1-10.6 GHz spectrum by the Federal Communications Commission (FCC) for Ultra Wideband (UWB) radio applications has presented a myriad of exciting opportunities and challenges for design in the communications arena, including antenna design. Ultra Wideband Radio requires operating bandwidths up to greater than 100% of the center frequency. Successful transmission and reception of an Ultra Wideband pulse that occupies the entire 3.1-10.6 GHz spectrum require an antenna that has linear phase, low dispersion and VSWR [< or =] 2 throughout the entire band. Linear phase and low dispersion ensure low values of group delay, which is imperative for transmitting and receiving a pulse with minimal distortion. VSWR [< or =] 2 is required for proper impedance matching throughout the band, ensuring at least 90% total power radiation. Compatibility with an integrated circuit also requires an unobtrusive, electrically small design. The focus of this thesis is to develop an antenna for the UWB 3.1-10.6 GHz band that achieves a physically compact, planar profile, sufficient impedance bandwidth, high radiation pattern and near omnidirectional radiation pattern.
by Johnna Powell.
S.M.
Snyman, A. (Anton). "Synthesizer modulation for wideband FM generation." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/49736.
Full textENGLISH ABSTRACT: The high performance of present digital phase-locked loops makes it the preferred choice for the generation of stable, low noise, tunable local oscillators in wireless communications applications. Most transmitters use superheterodyn techniques for up-conversion of the modulated signal to the required transmission frequency. Another technique is to inject the modulation signal into a phase-locked loop and consequently generate a frequency modulated signal directly at the transmission frequency. The aim of this study is to obtain a synthesizer configuration for the effective generation of wideband FM, considering both passive and active loop filters. The selection is based on synthesizer output signal quality, settling time and loop response to the modulation signal.
AFRIKAANSE OPSOMMING: Die hoe werksverrigting van fase-sluit lusse maak dit die verkiesde keuse vir die generasie van stabiele, lae ruis, verstelbare ossillators vir draadlose kommunikasie toepassings. Meeste senders gebruik "superheterodyn" tegnieke vir die op-menging van die gemoduleerde sein na die verlangde uitsaai frekwensie. 'n Ander tegniek is om die modulasie sein in 'n fase-sluit Ius te voer en so doende 'n gemoduleerde sein direk by die transmissie frekwensie te genereer. Die doel van hierdie studie is om 'n sintetiseerder konfigurasie te verkry vir die effektiewe opwekking van 'n wyeband FM sein, deur beide passiewe en aktiewe Ius filters in konsiderasie te neem. Die seleksie geskiet gebaseer op sintetiseerder uittree sein kwaliteit, sluit tyd en Ius gedrag as gevolg van die modulasie sein.
Utter, Marcus. "Indoor Positioning using Ultra-wideband Technology." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-277261.
Full textBerdugo, Albert. "ADVANCED DISTRIBUTED WIDEBAND DATA ACQUISITION SYSTEM." International Foundation for Telemetering, 2005. http://hdl.handle.net/10150/604918.
Full textWideband data acquisition units have been used as part of an instrumentation system for several decades. Historically, these units operated asynchronously from each other, and from the rest of the instrumentation system when installed on the same test vehicle. When many wideband units are required to slave their formats or sampling rate to the test vehicle’s event of interest such as external computer event clock, radar, or laser pulse train; few solutions were available. Additionally, a single test vehicle may use ten to thirty wideband units operating at up to 20 Mbps each. Such systems present a challenge to the instrumentation engineers to synchronize, transmit safety of flight information, and record. This paper will examine a distributed wideband data acquisition system in which each acquisition unit operates under its own data rate and format, yet remains fully synchronized to an external fixed or variable simultaneous sampling rate to provide total system coherency. The system aggregate rate can be as low as a few Mbps to as high as 1 Gbps. Data acquired from the acquisition units is further multiplexed per IRIG-106 chapter 10 using distributed data multiplexers for recording.
Mason, Terry. "ADVANCES IN WIDEBAND VHS CASSETTE RECORDING." International Foundation for Telemetering, 1992. http://hdl.handle.net/10150/608887.
Full textIn recent years, many designers have turned to digital techniques as a means of improving the fidelity of instrumentation data recorders. However, single and multi-channel recorders based on professional VHS transports are now available which use innovative methods for achieving near-perfect timebase accuracy, inter-channel timing and group delay specifications for long-duration wideband analog recording applications. This paper discusses some of the interesting technical problems involved and demonstrates that VHS cassette recorders are now a convenient and low cost proposition for high precision multi-channel wideband data recording.