Sökning: "active antennas"
Visar resultat 1 - 5 av 40 avhandlingar innehållade orden active antennas.
1. Wideband Active and Passive Antenna Solutions for Handheld Terminals
Sammanfattning : This thesis presents solutions and studies related to the design of wideband antennas for wireless handheld terminal applications. A method of electrically shortening the terminal chassis length to obtain resonance at high frequencies has been proposed and evaluated, thereby increasing the antennas impedance bandwidth. LÄS MER
2. Integrated Antennas : Monolithic and Hybrid Approaches
Sammanfattning : This thesis considers integration of antennas and active electronics manufactured on the same substrate. The main topic is on-chip antennas for commercial silicon processes, but hybrid integration using printed circuit board technology is also addressed. LÄS MER
3. Miniaturized Hard Waveguides in Multifunction Array Antennas
Sammanfattning : Recent advances in technologies of wireless communications systems have led to an increasing desire for several antennas performing diverse functions at different frequencies to be integrated into a common radiating aperture. This gives rise to the so-called multifunction antenna, which affords the saving of scarce premium real estate and can alleviate problems arising from excessive antenna protrusions in aspects such as aerodynamics, aesthetics, and stealth capability in military applications. LÄS MER
4. Integrated Antenna Solutions for Wireless Sensor and Millimeter-Wave Systems
Sammanfattning : This thesis presents various integrated antenna solutions for different types of systems and applications, e.g. wireless sensors, broadband handsets, advanced base stations, MEMS-based reconfigurable front-ends, automotive anti-collision radars, and large area electronics. LÄS MER
5. Modeling Approaches for Active Antenna Transmitters
Sammanfattning : The rapid growth of data traffic in mobile communications has attracted interest to Multiple-Input-Multiple-Output (MIMO) communication systems at millimeter-wave (mmWave) frequencies. MIMO systems exploit active antenna arrays transmitter configurations to obtain higher energy efficiency and beamforming flexibility. LÄS MER