Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 9 of 9 for “"circular polarisation"”.
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Optimising the axial ratio bandwidth of resonant linear to circular polarisation converters
… of converting a linearly polarised wave to a circularly polarised wave whilst simultaneously filtering an incident signal at 'out of band' frequencies. Printed FSS's fit for this purpose have been widely reported in technical literature, leaving room for improvement on research into slot based …
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Investigation into the design of broadband singly-fed electromagnetically coupled patch (EMCP) antenna elements and arrays for circular polarisation
… pose extraordinary demands on broadband circularly polarised (CP) antenna elements and high-performance antenna arrays. The use of high-dielectric-constant materials as the substrate for the driven layer and a low-dielectric-constant material as superstrate for the radiating patch …
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Polarimetry of magnetic cataclysmic variables
… adopted. This permitted simultaneous linear and circular polarisation measurements, or, by rearranging the order of the retarders in the beam, linear polarisation measurements alone, or circular polarisation measurements alone, with enhanced efficiency. The polarimeter was found to have extremely …
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Structural Colour in Fruits
… walls which act as photonic crystals to reflect circular polarised light. Here, the spectral and morphological characteristics of photonic cell walls in this and three other Pollia species are reported and it is shown that the unusual right handed circular polarisation reflection is apparent in …
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Analysis and design of linear-to-circular polarising reflector antennas exploiting periodic metallodielectric arrays
… an efficient way to analyse and design linear-to-circular polarising reflector antennas comprising doubly periodic metallodielectric arrays. These type of structures, used in conjunction with subreflectors, has risen as a promising solution to reduce the number of reflectors in multi-beam antennas in …
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Solid-state photonic interfaces using semiconductor quantum dots
… qubits and solid-state qubits. Indeed, the polarisation state of a photon was transferred into the spin state of an electron-hole pair and eventually restored through radiative recombination of the electron and the hole with a fidelity up to 95%. Moreover, spins were manipulated using …
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Collective charged particle dynamics in relativistically transparent laser-plasma interactions
… on the target areal density, laser intensity and polarisation. The results show a maximum laser transmission for the thinnest targets investigated, which decreases exponentially with increasing target thickness. The same trend is obtained for linearly and circularly polarised laser light. However, …
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Graphene Integrated Metamaterial Devices for Terahertz Modulation
… to active control of the amplitude, phase, polarisation and frequency of THz radiation. Chapter 1 discusses two THz sources: THz time-domain spectroscopy (THz-TDS) and THz quantum cascade lasers (THz-QCLs). A range of THz modulator architectures will then be discussed, focusing on the …
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Structural colour from a helicoidal cellulose architecture in the secondary cell wall: Optical properties, cell wall composition, structure and morphology of components, and their assembly and interactions.
Structural colours are produced by constructive interference of light scattered from periodically arranged interfaces within nanostructured materials. A common strategy of plants to achieve structural coloration consists of assembling cellulose microfibrils into helicoidal structures. Examples of …