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 19 of 19 for “"class-AB"”.
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Energy efficient radio frequency system design for mobile WiMax applications. Modelling, optimisation and measurement of radio frequency power amplifier covering WiMax bandwidth based on the combination of class AB, class B, and C operations.
… distortion, whilst making best use of the available power resources for amplification. However, the present work goes beyond this by investigating a new line of amplifiers that address the green initiatives, namely green power amplifiers. This research work explores how to use the Doherty …
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Efficiency Improvement of WCDMA Base Station Transmitters using Class-F power amplifiers
… and efficiency. As a result of this trade-off a Class-AB power amplifier is most often used in QPSK based systems. Class-AB power amplifiers provide acceptable linearity at efficiency values around 45-50% typically. This compromise is not a satisfactory solution but is inevitable while using …
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Performance Comparison of Harmonically Tuned Power Amplifiers at 28 GHz in SiGe BiCMOS
… three single-stage power amplifiers (PAs): class-AB, class-F and inverse class-F (class-F-1) at 28 GHz. The PAs have identical input networks: input matching, base DC feed, and base stabilizing networks. At the load side, there is a different load network for each PA. Class-AB PA load …
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Design of micropower operational amplifiers
… this thesis presents a design of micropower Class AB operational amplifiers which has the ratio of gain bandwidth product to supply current higher than that of an existing IC. The design is in a 0.6pxm CMOS process. The input stage of the design has the folded-cascode architecture that allows …
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Linearity Enhancement of High Power GaN HEMT Amplifier Circuits
Gallium Nitride (GaN) technology is capable of very high power levels but suffers from high non-linearity. With the advent of 5G technologies, high linearity is in greater demand due to complex modulation schemes and crowded RF (Radio Frequency) spectrum. Because of the non-linearity issue, GaN …
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Designing an Efficient Power/Control System for a Network of Piezoelectric Speakers
… explored here: a common-emitter paired with a class AB amplifier, and a class D amplifier. Although testing was limited due to an unsuccessful 200V power supply design, the class D amplifier was found to be the more efficient solution with a wider voltage range. However, the class AB amplifier …
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High performance Deep Learning based Digital Pre-distorters for RF Power Amplifiers
… their performance with simulation results on class-AB and class-F⁻¹ PAs. The simulation results show that both the learning methods lead to an improvement of more than 12 dB and 11dB in the linearity of class-AB and class-F⁻¹ PAs respectively, with indirect learning DL-DPD offering marginally …
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Design and Linearization of Energy Efficiency Power Amplifier in Nonlinear OFDM Transmitter for LTE-5G Applications. Simulation and measurements of energy efficiency power amplifier in the presence of nonlinear OFDM transmitter system and digital predistortion based on Hammerstein-Wiener method
… explores the design and implementation of 15.5 W class AB RF power amplifier, adopting a balanced technique to stimulate efficiency enhancement and redeeming exhibition of excessive power in the transmitter. Consequently, this work goes beyond improving efficiency over a linear RF power amplifier …
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A 77GHz power amplifier in silicon germanium BiCMOS technology
… the challenges and design of a 2-stage cascoded class-AB 77GHz power amplifier that could be used for imaging applications. Simulation results show a maximum output power of 20dBm, 26dB gain, and a maximum power-added efficiency (PAE) of 16%.
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The C. elegans class A synthetic multivulva genes inhibit ectopic RAS-mediated vulval development by tightly restricting expression of lin-3 EGF
The class A and B synthetic multivulva (synMuv) genes of C. elegans redundantly antagonize an EGF/Ras pathway to prevent ectopic vulval induction. The class B synMuv genes encode many proteins known to remodel chromatin and repress transcription. The class A synMuv genes likely also function in …
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Design of RF CMOS Power Amplifier for UWB Applications
… For the first part of this work, a PA suitable for MB-OFDM specifications was designed and fabricated in TSMC 0.18um CMOS technology. The class-AB PA is able to cover the lower UWB frequency band from 3.1 GHz to 4.75 GHz and delivers an output power of -2 dBm at 4 GHz. Simulated results …
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AC Power Combining Strategy with Application to Efficient Linear Power Amplifiers
… from high peak to average power ratios. Standard Class A and Class AB amplifiers cannot simultaneously achieve good linearity and efficiency, and therefore there has been an increase in the development of new topologies to combat this issue. Common features to these circuits is power combining of …
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Analytical Modeling and Design of High-Efficiency Input-Output Harmonic Tuned Microwave Power Amplifiers
… frequency (RF) transmitting system design. To enable modern and future wireless communication systems, the quest for efficient, wideband, and linear PA design techniques is ongoing. To cope with the stringent and contrasting requirements of modern wireless communication systems, it is important …
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A Distortion Suppression Technique for a Digital Class D Audio Power Amplifier with Pulse Density Modulation
… MP3 players, and high power amplifiers for portable speakers require high power efficiency and superior audio quality. The compact design of portable electronics has also increased the need to reduce the amount of Electromagnetic Interference (EMI) generated. Switching audio Class D amplifiers …
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A Linear RF Power Amplifier with High Efficiency for Wireless Handsets
… frequency response. The amplifier is thus able to operate in multiple modes (2G/2.5G/3G/4G). The design techniques provide contributions to current research in handset power amplifiers, especially to the converged power amplifier architecture, to reduce the number of power amplifiers within …
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Design of a Highly Linear 24-GHz LNA
… the peaking technique, which results in considerable linearity improvement. Loading the LNA with class AB amplifier, power gain experiences a peaking in high input signal swing levels. The next stager after the LNA is the buffer to provide isolation between the LNA and mixer, and also avoid …
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Design of Low Power Integrated Radios
… of the proposed techniques has been verified by fabricating them in two standard CMOS processes: TSMC's 65nm and IBM's 130nm process. These designs are compatible with all the channels defined in IEEE 802.15.6 standard in the frequency range of 2.36 GHz to 2.484 GHz. First, an IEEE 802.15.6 …
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Koncový zesilovač a subwoofer pro automobil
Tato práce popisuje návrh dvou výkonových zesilovačů pro subwoofer a pro čtyři základní automobilové reproduktory. Dále je součástí práce řešení napájecích obvodů těchto zesilovačů. Ovládání zesilovačů je realizováno pomocí procesoru. Dále se věnuje problematice spojené s ozvučením automobilu, …
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Σχεδίαση αναλογικών ολοκληρωμένων φίλτρων χαμηλής τάσης τροφοδοσίας στο πεδίο του υπερβολικού ημιτόνου
Η παρούσα διδακτορική διατριβή εστίασε το ενδιαφέρον της στην διερεύνηση των αναλογικών ολοκληρωμένων φίλτρων της κατηγορίας ELIN εξωτερικά γραμμικά, εσωτερικά μη-γραμμικά. Συγκεκριμένα μελετήθηκαν και σχεδιάστηκαν, νέες δομές φίλτρων συμπίεσης-αποσυμπίεσης του προς επεξεργασία σήματος στο πεδίο …