Visar resultat 1 - 5 av 103 avhandlingar innehållade ordet millimeter-wave.
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
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
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
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
Sammanfattning : The available bandwidth in wireless communication systems, such as the 802.11 family, is very limited. Together with the ever increasing data traffic, this causes problems. New possibilities are, however, available thanks to wide license-free bandwidth allocated at higher frequencies. LÄS MER