The solution consists of Rohde & Schwarz’ AREG800A automotive radar echo generator as the backend and the R&S QAT100 antenna array as the front end. Today, transversely moving objects are simulated by the mechanical movement of antennas. The R&S RTS replaces this mechanical movement by electronically switching individual antennas on and off in the front end. Even very fast transversely moving objects can thus be simulated reliably and reproducibly. The R&S RTS simulates the speed (Doppler) and size (radar cross section) of the objects at any adjustable distance – even if this distance is very small. Numerous objects can be displayed via cascading. With the system, tests that are currently carried out in road tests can be transferred to the laboratory. Errors can thus be detected at an early stage and costs significantly reduced.
An important background to the provision of the new test system lies in the fact that the number of radar sensors in the vehicle is continuously growing: in addition to the long-range radars required by the NCAP (New Car Assessment Programme), car designers are increasingly installing side radars that can also monitor cross-traffic. The latest generation of radar sensors integrates HF antennas and signal processors for object detection in one chip. Therefore, when testing the radar sensors, it is necessary to simulate the objects to be detected via the air interface. The new R&S RTS – consisting of the R&S AREG800A backend and R&S QAT100 antenna array front end – provides a target simulator for generating dynamic radar echoes that can be used from predevelopment through the hardware-in-the-loop test lab to the validation of ADAS/AD functions in the complete vehicle.
The backend can generate a large number of independent artificial objects, dynamically varying distance, object size (radar cross section) and radial velocity. A bandwidth of 4 GHz between 76 GHz and 81 GHz covers the typical frequency range of current and future automotive radar sensors.
The front-end enables the simulation of objects moving transversely to the direction of travel by means of up to 192 individually switchable antennas. This guarantees a very fine resolution, high switching speed and high repeatability. The electronic switching of the antennas does not cause any wear on HF cables or other moving parts as is otherwise usual with mechanical movement of the antennas. By means of an optional transmit line, two very close neighbouring transversely moving objects can be simulated. The small patch antennas, together with the surface covered by absorbers, ensure a low-reflection HF front end with a very small radar cross-section. This reduces the sensor’s background noise and suppresses near targets as well as potential multipath reflections. The antenna spacing of only 3.7 mm provides very fine angular resolution. To cover larger radar sensor fields of view, several front ends can be combined. An angular resolution of less than 0.5° is feasible.
Starting with simple scenarios such as Automatic Break Assist (AEB), the R&S RTS can also be expanded for complex scenarios with multiple radar sensors thanks to its modularity and scalability. For this purpose, any number of R&S QAT100 front ends and R&S AREG800A back ends can be combined. One of the backends takes over the synchronisation of all components installed in the setup. The test setup is easy to set up and configure via the graphical user interface with touch screen.
The R&S RTS has a hardware-in-the-loop (HiL) interface in accordance with the ASAM Open Simulation Interface for test automation with industry-standard tools.