1. Semi-analytical modelling and fabrication technology of RTD oscillators

Main supervisor: Michael Feiginov

• First task: To develop a simplified semi-analytical model for accurate description of injection locking in RTD oscillators. Physics-based modelling of RTDs and RTD oscillators builds the background for this work.
• Second task: Fabrication (micro- and nano-technology) of RTD-oscillator samples for experimental investigation of injection locking and demonstration of communication/ranging with phase/frequency-controlled RTD oscillators.

2. Experimental investigation and fabrication technology of RTD oscillators

Main supervisor: Holger Arthaber

• First task: Precise experimental measuring and characterizing injection locking mechanism in RTD oscillators. Test samples in the millimetre wave range are used here. Those samples will be also designed with a communication/ranging application in mind.
• Second task: Fabrication (micro- and nano-technology) of RTD-oscillator samples for experimental investigation of injection locking and demonstration of communication/ranging with phase/frequency-controlled RTD oscillators.

3. Communication/ranging with RTD oscillators

Main supervisors: Andrea Ortiz, opens an external URL in a new window and Christoph Mecklenbräuker, opens an external URL in a new window

• First task: Theoretical investigation of fundamental limits for coherent and incoherent communication/ranging and their asymptotic behaviors. The phase noise characteristics of injection-locked RTD oscillators are simulated and coherence time measurements are carried out on manufactured prototypes.
• Second task: Based on this theoretical investigation and the coherence time characteristics, prototypical designs of incoherent, differentially coherent, and coherent communication/ranging are identified, manufactured, measured, and analysed. The measurements are compared to the fundamental limits.

4. Numerical simulation techniques for the analysis of arrays of RTD oscillators

Main supervisor: Hans Georg Brachtendorf, opens an external URL in a new window

• First task: To develop simulation algorithms and tools for driven and mutual injection locking for RTD oscillators. This includes harmonically, sub- and super-harmonically injection locking. The numerical models shall go beyond the simplified models, based on the Van der Pol equation, and take into account realistic nonlinearities of RTDs.
• Second task: The models and simulation algorithms will be verified with measurements of RTD oscillators. They will be further used in design and analysis of communication and ranging application scenarios for RTD oscillators.

5. Equation learning methods for nonlinear models for RTD oscillators

Main supervisor: Gabriel Kronberger, opens an external URL in a new window

• First task: The outcomes of the measurements of nonlinear behavior of RTD oscillators, as well as the outcomes of the nonlinear analytic and numerical simulations are rather complex and not readily usable in the analysis and design of RTD oscillators. Therefore, the aim is to synthesize accurate models of dynamical systems directly from measurements of real components or from the outcomes of simulations by equation learning (symbolic regression) of parametric differential equation systems.
• Second task: To verify accuracy of the synthesized models in the comparison with experimental data and the results of communication/ranging experiments.