Search for dissertations about: "narrowband filter"

Showing result 1 - 5 of 16 swedish dissertations containing the words narrowband filter.

2. 1. Gap Waveguide for High Frequency Microwave Application- Validation of Concept, Filter Design & Packaging Aspects

   Author : Ashraf Uz Zaman; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; parallel plate stopband; PMC packaging; gap waveguide; fractional bandwidth; Quasi-TEM mode; PMC surface; narrowband filter; high Q resonators;

   Abstract : The overall goal of this thesis is to validate the low loss performance of recently evolved gap waveguide technology and to use this low loss technology for designing critical passive microwave component such as narrow band filter. Also, the exploitation of gap waveguide concept as a packaging solution for densely packed RF circuitry has been presented in this thesis. READ MORE

4. 2. Programmable and Tunable Circuits for Flexible RF Front Ends

   Author : Naveed Ahsan; Aziz Ouacha; Sten Gunnarsson; Linköpings universitet; []
   Keywords : Microwave circuits; phase shifters; programmable circuits; active corporate feed network; four-port circuit; generic cells; phase shift capability; programmable microwave function array; tunable recursive filter; TECHNOLOGY; TEKNIKVETENSKAP;

   Abstract : Most of today’s microwave circuits are designed for specific function and specialneed. There is a growing trend to have flexible and reconfigurable circuits. Circuitsthat can be digitally programmed to achieve various functions based on specific needs. READ MORE

5. 3. Gap Waveguide: Low Loss Microwave Passive Components and MMIC Packaging Technique for High Frequency Applications

   Author : Ashraf Uz Zaman; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Quasi TEM; Slot Array; PMC; Gap waveguide; Narrow-band Filter;

   Abstract : The heavy congestion at the existing radio frequency spectrum allocated for the today’s wireless communications motivates and accelerates the research work at mmWave bands or even higher frequency range where more spectrum space is available for massive data rate delivery. The inclination of modern wireless system research and development is towards small size, reliable, high-performance and high-yield microwave multifunctional products. READ MORE

6. 4. Spectral control of lasers and optical parametric oscillators with volume Bragg gratings

   Author : Björn Jacobsson; Fredrik Laurell; Uwe Morgner; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; volume Bragg gratings; single-longitudinal-mode laser; laser tuning; erbium; neodymium; ytterbium; nonlinear optics; optical parametric oscillator; KTP; tunable optical parametric oscillator; narrowband optical parametric oscillator; Physics; Fysik;

   Abstract : I den här avhandlingen visas hur lasrar och optiska parametriska oscillatorer (OPO:er) kan styras spektralt med hjälp av volymbraggitter. Volymbraggitter utgörs av ett periodiskt varierande brytningsindex som skrivits i ett fototermorefraktivt glas. READ MORE

7. 5. Material and technique development for ultrasound optical tomography using spectral hole burning filters

   Author : Alexander Bengtsson; NanoLund: Centre for Nanoscience; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biomedical imaging; ultrasound optical tomography; acousto-optical tomography; rare-earth-ion doped crystals; spectral holeburning; slow light filters; Tm 3:LaF3; Fysicumarkivet A:2022:Bengtsson;

   Abstract : The molecular sensitivity provided by optical photons has potential advantages in medical diagnostics, for example, in distinguishing healthy from cancerous tissue. However, scattering resulting from inhomogeneities in the refractive index of tissues prevents spatially resolved optical measurements in biological material, except at very shallow depths. READ MORE