Members of the defence committee:
- Chairman: Prof. Dr.-Ing. Jean-Régis Hadji-Minaglou, University of Luxembourg
- Vice-chairman: Prof. Dr.-Ing. Holger Voos, University of Luxembourg
- Supervisor: Prof. Dr.-Ing. Klaus Solbach, University of Duisburg-Essen, Germany
- Member: Prof. Dr.-Ing. Holger Heuermann, FH Aachen – University of Applied Sciences, Germany
- Member: Prof. Dr. Ulrich Sorger, University of Luxembourg
In this thesis, several new advancements in the field of linear and non-linear vector network analysis are presented. Three distinct but interconnected topics are addressed in this work:
First, the concept and feasibility of the single receiver vector network analyzer (VNA) architecture and the implications for existing error models are analyzed, starting with the one-port reflectometer, through two-port unidirectional 5-term, bidirectional 10-term and finally 7-term error models.
New VNA error models, which are able to capture the effects of the leaky RF receiver input wave selector switch, are derived, along with new calibration and correction procedures for this architecture. Modifications to the existing test-set architectures are introduced to reduce the effects of the leaky RF receiver input wave selector switch and shorten the required measurement time in this VNA architecture.
A purpose builds 275 MHz to 6000 MHz single receiver VNA system based upon commercial of the shelf components is presented and analyzed. Measurements carried out with this VNA system are used in conjunction with numerical test-set and VNA simulations to verify the efficacy of the new calibration and correction methods as well as different VNA test-set architectures according to EURAMET standards and procedures.
The second main topic of this thesis is the introduction of phase repeatable synthesizers as a new calibration and correction phase reference standard for non-linear VNA measurements. Due to the high output power capability of this new phase reference standard, new non-linear test-set and measurement scenarios such as the full non-linear two port characterization of high power solid-state amplifiers become possible, which were out of reach before due to low system signal-to-noise ratios provided by comb-generator based sources in this setup.
The third and final topic of this thesis integrates the contents and achievements of the two previous topics to prove and verify the feasibility of VNA based harmonic, i.e. non-linear, transponder-based stepped-FMCW radar systems operating directly in the frequency domain. A new stepped-FMCW theory based on mixed-frequency S-parameters is presented in conjunction with a phase-slope based ranging procedure which avoids time-domain transformation.
A complete system-analysis and modelling of the harmonic radar system including the passive transponder tag are provided. Numerous high-resolution measurements are presented and analyzed to verify the validity and accuracy of the non-linear harmonic radar equation, to evaluate illumination and harmonic return signal polarization based propagation effects in a multi-path indoor measurement scenario and to demonstrate the performance of the harmonic radar system in severe clutter situations.