Sökning: "optical antenna"

Visar resultat 1 - 5 av 22 avhandlingar innehållade orden optical antenna.

  1. 1. Systematic Antenna Design Using the Theory of Characteristic Modes

    Detta är en avhandling från Lund University

    Författare :Zachary Miers; Lunds universitet.; Lund University.; [2016-11-02]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Theory of Characteristic Modes; Antenna Design; Antenna; Characteristic Modes; Computational Electromagnetics; MIMO Systems; MIMO Antenna; MIMO; Mutual Coupling; Mobile Antenna;

    Sammanfattning : The day Faraday moved a magnet in and out of a wire loop and detected the time-varying magnetic field, the first wireless transmitter / receiver system was created and the world was changed forever. However, it took almost fifty years for Heinrich Hertz to use Maxwell's equations and Faraday's insights in his professorship at Karlsruhe to create the first electromagnetic wireless communication system using a spark gap dipole transmitter and a loop antenna-based receiver. LÄS MER

  2. 2. Study on electroabsorption modulators and grating couplers for optical interconnects

    Detta är en avhandling från Stockholm : KTH

    Författare :Yongbo Tang; KTH.; [2010]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Photonic integrated circuit; optical interconnect; transmission line; traveling-wave; electro-absorption modulator; hybrid silicon evanescent platform; grating coupler; vertical coupling scheme; optical antenna; lag effect; polarization beam splitter; TECHNOLOGY Electrical engineering; electronics and photonics Photonics; TEKNIKVETENSKAP Elektroteknik; elektronik och fotonik Fotonik; SRA - ICT; SRA - Informations- och kommunikationsteknik;

    Sammanfattning : Decades of efforts have pushed the replacement of electrical interconnects by optical links to the interconnects between computers, racks and circuit boards. It may be expected that optical solutions will further be used for inter-chip and intra-chip interconnects with potential benefits in bandwidth, capacity, delay, power consumption and crosstalk. LÄS MER

  3. 3. Molecular Trees for Collecting Sunshine -Monitoring and Controlling Energy Transfer in Dendrimers

    Detta är en avhandling från Department of Chemical Physics, Lund University

    Författare :Jane Larsen; Lunds universitet.; Lund University.; [2007]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetiska och optiska ; supraledare; magnetisk resonans; egenskaper elektriska; Kondenserade materiens egenskaper:elektronstruktur; supraconductors; magnetic resonance; relaxation; spectroscopy; Condensed matter:electronic structure; electrical; magnetic and optical properties; Kemi; Chemistry; Femtosecond transient absorption; Os-Ru metal ligand complexes; Cu-porphyrin-appended dendrimers; Zn-porphyrin-appended dendrimers; Annihilation; Energy transfer; Solar energy conversion; Artificial photosynthesis; Antenna systems; spektroskopi; Physical chemistry; Fysikalisk kemi; Photochemistry; Fotokemi; Femtosecond fluorescence anisotropy;

    Sammanfattning : Popular Abstract in Swedish Ett ökade förbrukningen av fossila bränslen kommer att accelerera den globala uppvärmningen med oöverskådlig inverkan på oss och vår miljö. Utvecklingen av alternativa, förnybara och miljömässigt rena energiformer är därför helt essentiell. LÄS MER

  4. 4. Photonic terahertz-wave generation, radiation and quasioptical integration

    Detta är en avhandling från Department of Chemical Physics, Lund University

    Författare :Biddut Kumar Banik; [2007]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; semiconductor device modelling; semiconductor diodes; III-V semiconductors; Catadioptric lens; imaging; dipole antennas; slot antennas; lens antennas; semiconductor heterojunctions; dielectric loaded antennas; optical mixers; photomixers; near-field imaging; computer aided engineering; indium compounds; millimetre wave imaging; near-field optics; submillimeter wave generation; photodiodes; terahertz sources; millimetre wave generation; submillimetre wave integrated circuits; microwave imaging; uni-travelling-carrier photodiodes;

    Sammanfattning : This thesis deals with the uni-travelling-carrier photodiode (UTC-PD) based photonic generation of terahertz waves, antenna designs for the terahertz radiation and a novelcatadioptric lens for quasioptical integration.The ongoing and accomplished research work on the UTC-PD, its limitations and optimisation scopes for attaining higher bandwidth and higher output power have been discussed. LÄS MER

  5. 5. Design, Characterization, and Calibration of Low-Noise Terahertz Receivers

    Detta är en avhandling från Department of Chemical Physics, Lund University

    Författare :Olle Nyström; [2011]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; receiver characterization; instrumentation; antenna design; Radio astronomy; calibration; optics;

    Sammanfattning : 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. LÄS MER