Search for dissertations about: "rf and antenna"
Showing result 16 - 20 of 58 swedish dissertations containing the words rf and antenna.
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16. Characterisation and Modelling of Graphene FETs for Terahertz Mixers and Detectors
Abstract : Graphene is a two-dimensional sheet of carbon atoms with numerous envisaged applications owing to its exciting properties. In particular, ultrahigh-speed graphene field effect transistors (GFETs) are possible due to the unprecedented carrier velocities in ideal graphene. READ MORE
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17. Design, Characterization, and Calibration of Low-Noise Terahertz Receivers
Abstract : This thesis is focused on the field of instrumentation for radio-astronomy and atmospheric science, and specifically deals with problems such as optical design and its verification, horn antennas and receiver optics’ components, different aspects of measurement systems in order to characterize low-noise THz receivers, and its calibration techniques.Ultra low-noise Terahertz receivers, used in radio-astronomy, are typically coupled to the telescope system through relay optics that provides guiding of the signal to the receiver frontend with minimal loss. READ MORE
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18. Frequency Reconfigurable and Linear Power Amplifiers Based on Doherty and Varactor Load Modulation Techniques
Abstract : In future mobile communication networks, there will be a shift towards higher carrier frequencies and highly integrated multiple antenna systems. The system performance will largely depend on the available RF hardware. As such, RF power amplifiers (PAs) with improved efficiency, linearity, and bandwidth are needed. READ MORE
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19. Polymer-Based Low-Cost Micromachining of Gap Waveguide Components
Abstract : The millimeter-wave (mmWave) and sub-millimeter-wave (sub-mmWave) frequency bands have gained significant attention over the past few years due to the growth of commercial wireless applications. As the operating frequency approaches these higher frequencies, the dimensions of the waveguide-based components continue to decrease. READ MORE
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20. Submillimeter-Wave Waveguide Frontends by Silicon-on-Insulator Micromachining
Abstract : This thesis presents novel radiofrequency (RF) frontend components in the submillimeter-wave (sub-mmW) range implemented by silicon micromachining, or deep reactive ion etching (DRIE). DRIE is rapidly becoming a driving technology for the fabrication of waveguide components and systems when approaching the terahertz (THz) frequency range. READ MORE