PIM Characterisation of the ESTEC Compact Test Range

This paper describes the measurement of the passive intermodulation (PIM) characteristics of the inside walls of the ESTEC Compact Test Range (CPTR). This was achieved using a radiative PIM measurement system with steerable directional antennas. The complete system was required to be road transportable. The PIM system employs purpose designed filters and antennas. The use of contactless connectors provides very stable and repeatable PIM residual performance, with no degradation on repeated reassembly. The measurement system is described with the procedures adopted for calibration and measurement. The results are processed to provide a contour mapping of the CPTR walls, showing the level of radiated PIM.