Measurement of Spread-Spectrum Radio Signals by Means of Wideband Field Probes

Field probes have been widely used, in the literature, for electromagnetic compatibility measurements and electromagnetic interference estimation. In the last two decades, these instruments have been exploited for open-space electric field exposure assessment, thanks to their ergonomics and capability to adapt to any scenario. This paper analyses the behaviour of field probes, in presence of digital spread-spectrum signals: OFDM (802.11a, 802.11g, 802.16x, DVB-x), W-CDMA (UMTS), DSSS (802.11b). The experiment was set-up in controlled environments, and the results were compared to referenced one, measured by means of bolometers or vector signal analysers. Some structural drawbacks were identified. Consequently, some conclusions about calibration needs were introduced.