Sökning: "active antennas"
Visar resultat 11 - 15 av 41 avhandlingar innehållade orden active antennas.
11. Analysis of microstrip structures for active and passive antennas and for hard surfaces
Sammanfattning : .... LÄS MER
12. Tuneable Recursive Active Monolithic Microwave Integrated Circuit Filters
Sammanfattning : In this thesis tuneable recursive active monolithic microwave integrated circuit (MMIC) filters are studied theoretically and experimentally. A possible future application for such filters is, for example, the microwave receivers of adaptive radar antennas. LÄS MER
13. Wide-angle scanning wide-band phased array antennas
Sammanfattning : This thesis considers problems related to the design and the analysis of wide-angle scanning phased arrays. The goals of the thesis are the design and analysis of antenna elements suitable for wide-angle scanning array antennas, and the study of scan blindness effects and edge effects for this type of antennas. LÄS MER
14. Reverberation Chamber Characterizations for Passive and Active OTA Measurements
Sammanfattning : Reverberation chamber (RC) has drawn more and more attention as a multipath emulator over the past decade. It has been used for antenna efficiency measurements. It has also been used to measure diversity gain and multi-input multi-output (MIMO) capacity using multi-port antenna. LÄS MER
15. Shape and material optimization for antenna applications
Sammanfattning : In this thesis, a gradient-based method for shape and material optimization fortwo antenna applications is presented: minimization of the active reflectioncoefficient for conformal array antennas; and minimization of the totalscattering cross section for cylindrical scatterers. The sensitivity of theobjective function with respect to changes of the shape and material of the geometry isexpressed in terms of the original field problem and an adjoint field problem. LÄS MER