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 13 of 13 for “"Power Combiner"”.
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Techniques for high-efficiency outphasing power amplifiers
… linearity and efficiency exists in conventional power amplifiers (PAs). The outphase amplifying concept overcomes this trade-off by enabling the use of high efficiency, non-linear power amplifiers for linear amplification. However, the efficiency improvement is limited by the efficiency of the …
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Efficiency improvement in nanometre CMOS outphasing power amplifiers
… is a pressing need for high-efficiency linear power amplifiers (PA) due to consumer demand for greater mobile data rates and battery lifetimes. The outphasing transmitter is one such technique that warrants research as it has yet to achieve commercial viability. It operates by decomposing a …
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Low loss microwave power combiners/dividers
… microwave solid state sources with output powers greater than that available from a single device a need for combining 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 …
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Broadband pin diode switching and phase shifting
… wider bandwidth but the diodes cannot perform as power devices due to their physical construction. Radiation due to discontinuities were found to degrade the isolation but this was overcome by an evanescent waveguide structure. The software program TOUCHSTONE (TM)/RF by EEsof is used extensively …
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A high frequency variable load inverter architecture
… immittance converter, which acts as a lossless power combiner. By controlling the amplitude and relative phase of the two constituent inverters the loading seen by each constituent inverter can be kept in a desirable range for wide variations in load impedance. This allows for the use of highly …
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Phase manipulation for efficient radio frequency transmission
Power amplifiers (PAs) for microwave communications are generally the most power-hungry element of a transmitter. High linearity is required for modern digital communications standards, and often is achieved at the expense of efficiency. Outphasing architectures, which combine multiple nonlinear …
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Efficiency enhancement techniques for RF and millimeter wave power amplifiers
Power amplifiers are the circuit blocks in wireless transceivers that require the largest power budget because of their relatively low efficiencies. RF designers cannot depend solely on the development better semiconductor devices in advanced deeply scaled process technologies to obtain improved …
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Broadband and Energy-Efficient Power Amplifier Architectures
In this dissertation, power amplifier circuits and architectures are proposed that provide high efficiency for spectral-efficient high peak-to-average power ratio signals that are being used in modern communications systems. Using the proposed amplifier architectures and circuits high efficiency …
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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.
… technology accounts for 3% and 2% of the global power consumption and CO2 emissions respectively. This alarming figure is on an upward trend, as future telecommunications systems and handsets will become even more power hungry since new services with higher bandwidth requirements emerge as part …
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Substrate integrated waveguide antenna systems
… ease of fabrication, low radiation loss, high power handling ability and low cost which makes it a very promising technology for current and future systems operating in K-band and above. Therefore, all the work presented in this dissertation focuses on SIW technology. Five di erent antenna …
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RELATIVISTIC BACKWARD WAVE OSCILLATOR WITH A GAUSSIAN RADIATION PATTERN AND RELATED TECHNOLOGIES
Short pulse high power microwave (HPM) devices with Gaussian radiation pattern are attractive for many applications. The importance of the Gaussian microwave beam is that its maximum energy density is concentrated on axis. The purpose of this study is to use a backward wave oscillator (BWO), which …
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The Design, Testing, and Analysis of a Constant Jammer for the Bluetooth Low Energy (BLE) Wireless Communication Protocol
… Each of these standards has tradeoffs concerning power consumption, range of communication, network formation, security, reliability, and ease of implementation. The most widely used standards for IoT are Bluetooth, BLE, and Zigbee. This paper discusses the vulnerabilities in the implementation of …
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CMOS Power Device Modeling and Amplifier Circuits
A power amplifier (PA) is a key part of the RF front-end in transmitters for a local broadband network. Today, commercial PAs are made of III-V HEMT and HBT technology with excellent results. An integrated system-on-chip power amplifier circuit using CMOS technology for cost-effective and …