Sökning: "thermal noise"

Visar resultat 6 - 10 av 115 avhandlingar innehållade orden thermal noise.

1. 6. Design of superconductor digital circuits for a 30 GHz DSP and for interface to qubits

   Författare :Samuel Intiso; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VHDL; thermal; RSFQ; noise temperature; Time-delay Optimization; WCDMA; Hierarchycal memory; DSP;

   Sammanfattning : Superconducting digital technology based on Rapid Single Flux Quantum logic (RSFQ) is a digital technology characterized by high speed, low power consumption and low operational temperatures. RSFQ is attractive for many applications and in particular for high frequency Digital Signal Processing (DSP) and for digital control of mK devices like superconducting qubits. LÄS MER

3. 7. Studies of acoustic waves, noise and charge pumping using single-electron devices

   Författare :Martin Gustafsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; single-electron pump; single-electron transistor; surface acoustic wave; single-electron devices; charge pumping; TLF; SINIS turnstile; electrometer; two-level fluctuator; single-photon detector; noise; SAW; SET;

   Sammanfattning : This thesis covers a range of experiments on single-electron devices, electrical circuits that utilize the discreetness of the electron charge. The Single-Electron Transistor (SET) is of special importance among these, being the most sensitive electrometer demonstrated, and sufficiently mature to serve as a building block in sensors and detectors for physical phenomena that can be transformed into charge signals. LÄS MER

4. 8. Radio Frequency Systems for NMR Imaging: Coil Development and Studies of Non-Thermal Biological Effects

   Författare :Lars Malmgren; Lunds universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; anechoic chamber; TEM transmission cells; FDTD; circularly polarized electromagnetic fields; reduced coupling; noise matching; matching networks; low noise amplifiers; upper thoracic spine; surface coils; Nuclear magnetic resonance; magnetic resonance imaging; non-thermal biological effects; blood-brain barrier; Electronics; Elektronik;

   Sammanfattning : This thesis concerns both design and optimization of NMR imaging systems and studies on non-thermal biological effects of electromagnetic fields. These two research fields are linked together by the fact that humans are subject to static and pulsed magnetic fields as well as to magnetic radio frequency fields (RF) during an NMR imaging investigation. LÄS MER

5. 9. Tread Braking of Railway Wheels - Noise-related Tread Roughness and Dimensioning Wheel Temperatures

   Författare :Tore V Vernersson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rail chill; block material; temperature; heat partitioning; railway; corrugation; thermoelastic analysis; tread braking; noise;

   Sammanfattning : Block braking is a commonly used braking system for freight wagons and other types of railway vehicles. One or several brake blocks are pressed against the tread (running surface) of the wheel, which is also in rolling contact with the rail. LÄS MER

7. 10. GaN HEMT Low Noise Amplifiers for Radio Base Station Receivers

   Författare :Pirooz Chehrenegar; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gallium nitride GaN ; radio base station receiver; cascode; high linearity; robustness.; cascade; high electron mobility transistor HEMT ; low noise; low noise amplifier;

   Sammanfattning : Gallium nitride (GaN) high electron mobility transistor (HEMT) has been introduced as the technology of choice for high power microwave applications due to its material properties including high saturation electron velocity and breakdown field together with excellent thermal conductivity and robustness.It is also a promising candidate for receiver front-ends in the radio base station(RBS) where low noise figure and high linearity are key issues for low noiseamplifier (LNA) design. LÄS MER