Effects of a near-field radio frequency interference on a marine navigational X-band radar

This paper discusses the effects of different types of radio frequency interferences on the radar receiver of a navigational X-band radar as displayed on the plan position indicator (PPI). In particular, this paper deals with the theoretical analysis of the predicted field strength of the envisaged measurement set-up followed by the description of the actual set-up and discussions on the observations and achieved results. The experimentation set-up in pursuit of specific user requirements include a radio frequency interference source placed in the near-field of the rotating radar antenna and an examination of the effects on the genuine target display on the PPI. For pulsed interference signals, the interferences appear as short radial lines on the PPI display causing confusion with genuine target echoes. For continuous wave (CW) interference signals the receiver noise level is elevated resulting in the loss of sensitivity and degraded radar detection performance.