Radome Tester Improves Precision To Material Reflection Measurements

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High performance make it the perfect tool for applications requiring verification of radome material and integration

The QAR is a mmWave imaging system for demanding radome and bumper material testing and validation. High performance and speed of operation make it the perfect tool for applications ranging from development and production to verification of radome material and integration of 76 GHz to 81 GHz radars.

The high spatial resolution comes at the cost of having a larger spread in terms of incident angles. A typical radar sensor has a certain field of view, e.g. +/-10° for full-range (FRR) and +/-60° for short-range radars (SRR). Derived from material characterisation techniques, the reflection parameters of radomes are mainly defined for perpendicular incident angles as these parameters can be measured using VNAs. The QAR-K50 software option addresses this topic.

Comparing the results delivered by the QAR to those measured with a standard vector network analyser (VNA) and a quasi-optical (QO) setup, some deviations can be seen with the larger aperture used by the QAR. This is where the QAR-K50 software option comes into play. It automatically detects the highest reflection from the material sample and averages over the test region. The mean value for the reflection area is determined and shown to the user as the measurement result within less than 7 seconds. This value matches very well the S11 and S22 reflection measurement results of a VNA.

The measurements made with VNA and QO setups during R&D can now be directly compared to the QAR measurements. Still utilising microwave imaging, but with a smaller antenna aperture, makes the setup less sensitive to positioning errors and more suitable for production environments compared to VNA setups.

The QAR-K50 software detects the correct measurement area by itself and provides optical feedback to the operator in case the positioning of the samples is slightly out of tolerance. The QAR then combines its high-resolution image used for homogeneity analysis (QAR-K10 software) with a robust and easy-to-use reflection measurement.

The QAR-K50 software option for single-cluster measurements can be installed on all Windows 10 instruments with most recent firmware using keycode activation. It is now available from Rohde & Schwarz.