High Accuracy Millimetre Wave Radar for Micro Machining

In cooperation of the two institutes FHR and IHE a high precision radar sensor was realised, which features a flexible integration in different micro machining modules. The feasibility of high precision and robust absolute measurements near the tool centre point is one of the main advantages of the radar technology. The realised radar sensor uses an integrated silicon-germanium (SiGe) transceiver chip which allows a cost-effective, energy-efficient, compact, and mass-market-capable solution. The system is working in the frequency range from 68 to 93 GHz providing a high modulation bandwidth of 25 GHz leading to a range resolution of a few mm and a record mu m-accuracy. For improving the measurement and reducing the fabrication costs of this measurement system another sensor working at 240 GHz was developed as well. With a compact design of the measurement front-end a flexible integration even in constricted available space is possible. In combination with the Field Programmable Gate Array (FPGA) back-end measurement rates up to 100 Hz can be achieved, thus a closed loop control of the micro machining tool can be realised.