Sökning: "radio frequency waves"

Visar resultat 21 - 25 av 35 avhandlingar innehållade orden radio frequency waves.

1. 21. Scattering of electromagnetic waves by a perfectly conducting half plane below a stratified overburden and applications to geophysical prospecting by VLF

   Författare :Olle Olsson; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Malmgeologi; Ore Geology;

   Sammanfattning : The present paper is an introduction to and a summary of a thesis consisting of the following papers:1. Scattering of electromagnetic waves by a perfectly conducting half plane below a stratified overburden. Radio Sci. (1978), Vol. LÄS MER

3. 22. Time-Domain Antenna and Scattering Analysis for Micro- and Millimeter-Wave Applications

   Författare :Iman Vakili; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Telecommunications industries are investing tremendously to meet the ever-increasing demands for higher data rates and capacity. In particular to develop standardization for 5G, which is expected around 2020. The existing spectrum for traditional mobile networks is limited to highly occupied bands at microwave frequencies below 6 GHz. LÄS MER

4. 23. Design and Characterization of D-band Monolithic Direct Carrier Modulator and Demodulator Circuits for High Speed Wireless Communication

   Författare :Sona Carpenter; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; modulator; MMIC; Double-Heterojunction Bipolar Transistor DHBT ; demodulator; balun; D-band; InP; Gilbert cell; Quadrature; differential coupler;

   Sammanfattning : Millimeter waves are finding increasing applications in data communication, sensing,imaging and radio astronomy. One application is in high-speed wireless back-haul networksfor mobile communication. The operators are interested in replacing optical fiber withthe more flexible and easy to deploy wireless link. LÄS MER

5. 24. On-chip terahertz characterisation of liquids

   Författare :Juan Cabello Sánchez; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dielectric permittivity; Through-Reflect-Line TRL calibration; vector network analyzers VNA ; terahertz spectroscopy; isopropyl alcohol IPA ; coplanar waveguides CPW ; water; on-wafer measurements; planar Goubau line; Chip; liquids; microfluidic channels; scattering parameters; material properties;

   Sammanfattning : Spectroscopy at terahertz frequencies can be used in a wide range of applications including radio-astronomy, pharmaceutical manufacturing control, and the study of processes in molecular biology. Biomolecular samples should preferably be studied in their native environment, water, however, water poses extreme attenuation for THz-frequency waves, deteriorating or even impeding analysis using these waves. LÄS MER

7. 25. Radar Probing of the Sun

   Författare :Mykola Khotyaintsev; Bo Thide'; Valentyn Mel'nyk; Christian Hanuise; Uppsala universitet; []
   Nyckelord :Space and plasma physics; solar radar; active experiments; space physics; solar corona; plasma; Rymd- och plasmafysik;

   Sammanfattning : This thesis is dedicated to the theory of solar radar experiments. The Sun exhibits a variety of interesting and complicated physical phenomena, examined mainly through analysis of its radiation. Active solar probing by radar provides an alternative possibility to study the Sun. LÄS MER