In-situ microwave measurement system for on-board catalyst state monitoring

It has been shown time and again that the internal state of automotive catalysts can be diagnosed with microwave (cavity perturbation) techniques. In this contribution, we propose a reflectometer solution, or one-port scalar network analyzer, which is small and cost-efficient enough to pave the way for actual on-board diagnostics. Our main goal is to qualify the characteristics of this system setup, which is very flexible in terms of power, frequency bandwidth, and configuration.