Sökning: "millimeter wave"

Visar resultat 1 - 5 av 131 avhandlingar innehållade orden millimeter wave.

1. 1. Millimeter-wave Networking : Fundamental Limits, Scalable Algorithms, and Design Insights

   Författare :Hossein Shokri-Ghadikolaei; Carlo Fischione; Gabor Fodor; Muriel Madard; KTH; []
   Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : The current demands for extremely high data rate wireless services and the spectrum scarcity at the sub-6 GHz bands are forcefully motivating the use of the millimeter-wave (mmWave) frequencies. The main characteristics of mmWave communications are severe attenuation, sparse-scattering environment, huge bandwidth, vulnerability to obstacles and antenna misalignment, massive beamforming, and possible noise-limited operation. LÄS MER

3. 2. Millimeter-Wave Photonics: Signal Sources and Transmission Links

   Författare :Andreas Wiberg; Chalmers University of Technology; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microwave photonics; mm-wave generation; radio over fiber; photonic frequency multiplication; millimeter-wave photonics; millimeter-waves; millimeter-wave communication system;

   Sammanfattning : With the use of higher and higher frequencies in a number of current and future wireless millimeter-wave applications it is beneficial to use photonics for several reasons. The use of optical fibers is an advantageous way to transport millimeter-waves in terms of loss, mechanical flexibility, weight, and insensitivity to electromagnetic interference. LÄS MER

4. 3. Millimeter and Sub-Millimeter Wave Integrated Active Frequency Down-Converters

   Författare :Yu Yan; Chalmers University of Technology; []
   Nyckelord :145 GHz; self-oscillating mixer; mixer; conversion gain; millimeter wave; radar; mHEMT; noise figure; monolithic; sub-millimeter wave; InP; THz; resistive mixer; Gilbert mixer; DHBT; SiGe; 340 GHz; 220 GHz; FMCW; transconductance mixer; BiCMOS; transceiver; harmonic; GaAs;

   Sammanfattning : In recent years, the increasing amount of data transmission, the need for automotiveradars, and standoff imaging for security applications are the main factors that accelerateresearch in the millimeter and sub-millimeter wave frequency ranges. The semiconductorindustries have continuously developed their processes, which have opened upopportunities for manufacturing monolithically integrated circuits up to a few hundredGHz, based on transistor technologies. LÄS MER

5. 4. Planar Quasiparticle Mixer Structures for Millimeter and Sub-Millimeter Wave Receivers

   Författare :Anders Skalare; Chalmers University of Technology; []
   Nyckelord :SIS receiver; dipole array antenna; slot substrate mode loss; millimeter wave regime; planar antennas; sub-millimeter wave regime; superconducting mixers; slot radiation; slot lines; slot wavelengths; Voltage Matching Method;

   Sammanfattning : The paper covers various aspects of integrating planar antennas with superconducting mixers in the millimeter and sub-millimeter wave regime. The construction of an 80-100 GHz tapered slot antenna and SIS mixer chip with a minimum double side band noise temperature of 240 K is described. LÄS MER

7. 5. Millimeter-Wave Impulse Radio

   Författare :Mats Ärlelid; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Compound semiconductor; resonant tunneling diode; ultra wideband; 60 GHz; on-off keying; transmitter; receiver; and super-regenerative oscillator;

   Sammanfattning : This thesis investigates the opportunity of wireless multi-gigabit per second communication at the millimeter-wave (mmW) frequencies around 60 GHz by using impulse radio and nanoelectronics. Today most wireless communication take place in the microwave region, where several different systems and applications are crowding the narrow-band channels. LÄS MER