Interference test system for ATC radar systems

Challenge

Air traffic control (ATC) S-band radar systems installed at airports cover the frequency range from 2.7 GHz to 3.1 GHz. These systems can be affected by interference from LTE and WiMAX™ signals in the adjacent frequency band from 2.496 GHz to 2.69 GHz. In many countries, the relevant frequency bands have been approved for use or will be activated in the near future. Various studies have proven that this  type of interference makes aircraft disappear from the radar screen, for example. The radar’s immunity to interference must first be determined, taking into account the radar and the conditions in the vicinity of the airport.

Solution

For this purpose, the R&S®TS6650 generates signals of up to 20 different LTE and WiMAX™ base stations and mobile stations and irradiates the radar with defined peak power levels of altogether 600 W using a directional antenna that is 100 m to 300 m away. At the same time, the system is protected against the radar’s transmit power, allowing tests during normal operation. The radar can be tested and corrective action taken before problems with installed base stations occur. The R&S®TS6650 makes it possible to detect interference in time and to ascertain the effectiveness of corrective action.

Key facts

  • Flexible, modular system based on standardized instruments; expandable for other interference tests

  • High suppression of intermodulation products and spurious emissions in radar band through decoupled, low-intermodulation filters

  • Tests in normal radar operating mode

  • High total field strength of ≥ 1 V/m Peak envelope power (PEP) at radar antenna 200 m away

  • Flexible setup at 100 m to 300 m from radar for taking local conditions into account

  • Verification of immunity using realistic scenarios involving multiple LTE and WiMAX™ emitters