Search for dissertations about: "noise equivalent power"

Showing result 1 - 5 of 45 swedish dissertations containing the words noise equivalent power.

  1. 1. On the Directivity of Railway Noise Sources

    Author : Xuetao Zhang; Chalmers University of Technology; []
    Keywords : railway traction noise; railway rolling noise; line source; railway aerodynamic noise; moving source; equivalent source line; De-Dopplerization; sound emission time; sound immission time; directivity; the Doppler factor;

    Abstract : This dissertation deals with the directivity of railway noise. The directivity of railway noise is of particular importance when we have high-rise buildings close to the track, tunnel openings, partial barriers, or when we calculate the maximum sound pressure level during a pass-by based on the sound power level of the different sub-sources of a train. READ MORE

  2. 2. Cold-Electron Bolometer with Superconductor-Insulator-Normal Metal Tunnel Junctions

    Author : Ian Jasper Agulo; Chalmers University of Technology; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; temperature sensitivity; cryogenfree; power sensitivity; noise equivalent power; cold-electron bolometer; SIN tunnel junctions; electron cooling;

    Abstract : The Cold-Electron Bolometer (CEB) is an ultrasensitive device designed for the detection of radiation in the terahertz region of the electromagnetic spectrum. The key to its sensitivity is the electron cooling of the absorber by the superconductor-insulator-normal metal (SIN) tunnel junction. READ MORE

  3. 3. Quantization and Noise-Shaped Coding for High Efficiency Transmitter Architectures

    Author : Ulf Gustavsson; Chalmers University of Technology; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Software Defined Radio; Quantization; damped Gauss-Newton; Pulse Density Modulation; Noise-Shaped Coding; ΣΔ-Modulators; Power Amplifier;

    Abstract : Three driving parameters in the development of transmitter technologies for wireless communication today is: energy efficiency, flexibility and footprint reduction. This thesis investigates the use of 1-bit oversampled signal representation, mainly as a power efficiency enhancement technique for the transmitter, but also as a path toward reduced footprint and increased flexibility. READ MORE

  4. 4. Design, Modelling and Control of Electrical Machines - With Applications to Iron-powder Machines and Acoustic Noise

    Author : David Martinez; Industriell elektroteknik och automation; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; BEM; induction machine; noise prediction; vector control; acoustic noise; HEV; series magnetization; leakage reduction; thermal model; FEM; MEC; claw-poles; SMC; slip-ring-less machine; sound intensity measurements; vibration; Electrical engineering; Elektroteknik;

    Abstract : This thesis consists of two parts, the first dealing with the design of iron-powder synchronous machines, and the second with the analysis and prediction of the acoustic noise in electrical machines. In Part I, a 1.6 kW electrically magnetized claw-pole machine with magnetically conducting end-plates has been analyzed and a prototype tested. READ MORE

  5. 5. Low Phase Noise GaN HEMT Oscillator Design based on High-Q resonators

    Author : Mikael Hörberg; Chalmers University of Technology; []
    Keywords : NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; resonator coupling; reflection oscillator; MMIC; phase noise; cavity resonator; low-frequency noise; GaN HEMT; MEMS;

    Abstract : The thesis considers the design and optimization of oscillators targeting low phase noise, given boundary conditions from the technology. Crucial technology figures are power capability, RF noise figure, low-frequency noise and the quality factor (Q-factor) of the resonator. READ MORE