Search for dissertations about: "High frequency radio waves"
Showing result 1 - 5 of 23 swedish dissertations containing the words High frequency radio waves.
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1. Radio waves in the ionosphere : Propagation, generation and detection
Abstract : We discuss various topics concerning the propagation, generation, and detec-tionof high-frequency (HF) radio waves in the Earth's ionosphere. With re-gardsto propagation, we derive a full wave Hamiltonian and a polarization evo-lutionequation for electromagnetic waves in a cold, stratified magnetoplasma. READ MORE
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2. HBV frequency multiplier 2D arrays and application
Abstract : The utilisation of the THz spectrum ( 0.3-3 THz ) is hampered by technological difficulties to generate power at these frequencies. READ MORE
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3. Opening New Radio Windows and Bending Twisted Beams
Abstract : In ground based high frequency (HF) radio pumping experiments, absorption of ordinary (O) mode pump waves energises the ionospheric plasma, producing optical emissions and other effects. Pump-induced or natural kilometre-scale field-aligned density depletions are believed to play a role in self-focussing phenomena such as the magnetic zenith (MZ) effect, i. READ MORE
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4. VLF and ULF Waves Associated with Magnetospheric Substorms
Abstract : A magnetospheric substorm is manifested in a variety of phenomena observed both in space and on the ground. Two electromagnetic signatures are the Substorm Chorus Event (SCE) and Pi2 pulsations. The SCE is a Very Low Frequency (VLF) radio phenomenon observed on the ground after the onset of the substorm expansion phase. READ MORE
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5. Millimetre wave waveguide enclosed grid frequency multipliers and imaging
Abstract : The utilisation of the THz spectrum ( 0.3-10 THz ) is hampered by fundamental difficulties in generating power at these frequencies. READ MORE