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A novel mechanically flexible filter integrated in a glass dielectric waveguide is presented for sensor applications at G-band (140–220 GHz). The use of laser-induced deep etching (LIDE) technology enables the production of via holes and thus the local modulation of the effective permittivity in a dielectric waveguide. This approach enables the implementation of a filter without the use of metal structures. In addition, extraordinary mechanical flexibility is achieved through meandering slots, which simultaneously perform the permittivity modulation. The RF performance was studied in full-wave simulations and validated by measurements of the manufactured bandstop prototypes. The experimental results of the implemented filter element show good agreement with the simulated values. At the center frequency of 156 GHz a notch depth below −14 dB in the measured stop band is achieved. Additional measurements show a stable filter characteristic at up to 8◦ bend angle applicable for the use as a low-loss waveguide under harsh environmental conditions, acceptedVersion

In this work, a novel multi-feed synthesis for holographic leaky-wave (LW) antennas is presented that considers the angular dependence of each pixel structure. This approach of combining multiple single-beam holograms minimizes the impedance error w.r.t. each individual impedance hologram. A multi-feed antenna with two feeding points at 20GHz is fabricated and measured using this new design methodology. The simulation and measurement results show a good agreement. The fabricated LW antenna has a gain of 21.7 dBi and 22.1 dBi and a side lobe level (SLL) of 9.0 dB and 9.6 dB for both feeds., acceptedVersion

A wideband and robust design of a dielectric rod antenna at G-band (140 GHz–220 GHz) for short range radar applications in harsh environmental conditions is presented. The proposed antenna is based on a simple plug-in solution made of PEEK material (εr,PEEK =3.2), which enables the mechanically detachable integration into a glass-encapsulated millimeter wave radar sensor system. To further increase the antenna gain, an optically transparent biconvex lens is presented. The antenna performance has been investigated by full wave simulations and validated through measurements of the fabricated antenna prototype. The experimental results of the realized antenna element show excellent agreement to the simulated values. The rod antenna covers a 3 dB-beam width of 46° and achieves a maximum gain of 12.4 dBi. The additional use of the dielectric lens increases the gain to 30.4 dBi with a stable beam pattern over the entire modulation bandwidth of 20 GHz of the radar sensor. The measured 3D-radiation patterns at various frequencies across the operational band are provided., acceptedVersion

Die vorliegende Arbeit befasst sich mit einem neuartigen Systemkonzept für aktive phasengesteuerte Gruppenantennen. Das potentielle Anwendungsgebiet sind Richtfunkverbindungen, wobei das Hauptaugenmerk auf der mobilen Satellitenkommunikation im K- und Ka-Band liegt. Neben der detaillierten Ausarbeitung der Aufbau- und Verbindungstechnik wird ein frei skalierbares Wärmeabfuhrkonzept für hochintegrierte Antennensysteme im Millimeterwellenbereich präsentiert. Besonders herausgestellt werden in dieser Arbeit verschiedene dual polarisierte Antennen, die selbst für sehr große Ablagewinkel eine ausgezeichnete Schwenkeffizienz und Polarisationsentkopplung aufweisen. Schließlich werden zwei Varianten eines aktiven Demonstratorsystems vorgestellt, die auf der ausgearbeiteten System- und Modularchitektur basieren.

A novel dual linearly polarized cavity antenna with excellent scan performance up to 60◦ in both E- and H-plane is presented. The highly integrated antenna element for Ka band Satcom on the move applications is operating in the uplink band at 30 GHz. Vertical stubs incorporated into the 3-D architecture are proposed to compensate parasitic effects limiting the scan volume of planar phased array antennas. To verify this approach, the vertical transition used in the design, and the entire antenna structure in single element configuration were fabricated and measured successfully., acceptedVersion

A novel dual-polarized stacked patch antenna element for wide-angle scanning satcom on the move applications at Ka-band is presented. The proposed highly integrated multilayer unit cell element operates from 27.8 to 30.8 GHz with excellent scan performance up to ±60° in both E- and H-planes. High port-to-port isolation in the entire scan volume evidences the antenna's distinguished suitability for integration into an active folded reflectarray transceiver architecture. Parasitic effects in planar array antennas degrading the intended scan volume are investigated using the infinite array analysis, and measures are introduced to suppress them efficiently. To validate the proposed antenna design, several configurations were fabricated and measured successfully. The experimental results show close agreement with the simulations and indicate its excellent scanning capabilities., acceptedVersion