Publikationen

The fundamental concept of a robust and compact GNSS-receiver and the first development steps and simulation results are presented. The receiver comprises a miniatur-ized antenna array with a novel decoupling and matching network to excite the eigenmodes of the array. In contrast to conventional multi-antenna solutions, these eigenmode patterns are used for digital beamforming and steering. Several array-processing algorithms to determine the directions-of-arrival of navigation signals, interferers and multipath (DOA/DOI) as well as mitigation procedures have been investigated and evaluated regarding their applicability on eigenmode patterns. They also have been modified if necessary. For fast signal processing new concepts for hardware implementation have been devel-oped. First results of the beamforming software and hardware performance are presented. The structural basis of the compact GNSS-receiver is a miniaturized antenna element designed for operation in the E1 band. Suitable front ends, fabricated in 0.18-[my]m CMOS technology, further support the compactness of the receiver. Design and construction of antenna and front end are discussed in detail. Finally, to test and demonstrate the precision of naviga-tion and the receiver robustness against interference in a disturbed environment, a suitable demonstrator will be built of which the fundamental concept is presented.

We provide that cellular composition of bacteria could be identified by dielectric spectroscopy. Gram-positive and negative bacterial strain permittivity measurement was performed in frequency range from 50-300 MHz. The results demonstrated connectivity from cell count and permittivity. A clear discrimination between real part of permittivity of Gram-positive and -negative strains was possible.

A compact 4x4 reconfigurable switch matrix based on LTCC technology is presented for Ka-band space applications. The key features include the embedded matching networks, optimized interconnect, vertical transitions, integration of digitally controlled bipolar current sources and a redundancy concept for power-failure. The benefits include 40% surface area reduction and elimination of peripherals.