Applications of photonic bandgap structures with arbitrary surface impedance to Luneburg lenses for automotive radar [Elektronische Ressource] / Young-Jin Park

ForschungsberichteausIHE dem Institutfür Höchstfrequenztechnikund ElektronikderUniversität KarlsruheHerausgeber:Prof. Dr.-Ing. W. WiesbeckYoung-Jin ParkApplications of Photonic BandgapStructures with Arbitrary SurfaceImpedance to Luneburg Lensesfor Automotive RadarBand 33Copyright: Institut fur¨ Hochstfrequenztechnik¨ und Elektronik (IHE)¨Universitat Karlsruhe (TH), 2002alle Rechte vorbehaltenDruck: Druckerei Gunter Dunnbier¨ , 02779 Großschonau,¨Tel. 035841-36757ISSN: 0942-2935Institut fur¨ Hoc¨ hstfrequenztechnik und Elektronikder Universitat¨ Karlsruhe (TH)ForewordAntennas in the millimeter wave range require a number of different considerations andexhibit constraints which we do not face at lower frequencies, for example in the mobilecommunication bands. The most severe problems are introduced by the increasedlosses and the thereby reduced efficiencies. Another problem is that millimeter waveantennas, especially if they require higher gain, are more conveniently consideredwith ray optical techniques. The usually most stringent problems are the involved costbecause of the special materials and the high absolute precision. This, all together,leads to the task to avoid in millimeter waves antennas any dielectric materials, toreduce surface currents as much as possible and to develop a mechanical design thatcan be reproduced by casting and if required metallization of dielectric parts.Dr.