Spectrum-Analyzer-Based Radar System Measurements in a Compact Antenna Test Range

Highly integrated radar systems are continuously brought to evermore areas of application. However, the integration of antennas and transceivers complicates or even prevents conventional passive antenna measurements. To obtain reliable results, the entire system should be measured instead of individual components only. A measurement setup, that does not require physical connection to the antenna ports nor a phase reference from the transceiver chip, is integrated in the compact antenna test range at the Institute of High Frequency Technology at RWTH Aachen University. It is utilizing a state-of-the-art 85 GHz spectrum analyzer to measure the direction-dependent radiated power of a radar module's transmit antennas. The setup is tested with different antenna types and arrays connected to an in-house designed evaluation board, operating in the E-Band. Dynamic range and uncertainty analysis are carried out to explain the capabilities and limitations of such a setup.