Sensors Radar Testing with an O-scope by Ernst Flemming and Andreas Ritter Four-channel oscilloscopes are ideal for characterizing the new generation of automotive radar sensors, as two experts explain. A new generation of compact radar sensors with Rohde & Schwarz long range and high resolution is under development for automated driver-assistance systems (ADAS) and future fully autonomous vehicles. Operating in the frequency range from 76 GHz to 81 GHz, these sensors use phased-array antennas to obtain location information. The accuracy of the obtained data is directly correlated to the accuracy of the relative phase angles of the emitted signals, making precise adjustment of the antenna system a crucial factor for precision. Characterization of these sensors in the development phase requires sophisticated testing and measurement equipment due to the high frequencies. Oscilloscopes are ideal for this because they can simultaneously analyze multiple signals and precisely compare them. While some spectrum analyzers offer dynamic range and sophisticated analysis features, they have only one input channel and therefore are not able to measure the phase differences of multiple signals. Four-channel oscilloscopes have an advantage Fig. 1: Test setup for multichannel radar analysis with an oscilloscope. The radar signal is down-converted to an IF frequency of 3 GHz by the harmonic mixers and fed to the oscilloscope. The power splitter and one mixer are not needed for a test setup with only one channel. AUTONOMOUS VEHICLE ENGINEERING July 2020 23