Automatic direction-finding antenna ADFA 1 from Narda.

Narda offers the ADFA 1 antenna for direction finding measurements

  • Narda Safety Test Solutions has developed the automatic direction-finding antenna ADFA 1 for use with its SignalShark real-time receiver.
  • This solution ensures a complete measurement cycle in 1.2 milliseconds.
  • According to Narda, this solution is distinguished by its insensitivity to the parasitic reflections of urban environments and to the stability of measurements.
  • The ADFA 1 antenna, with a weight of only 5.6 kg and a diameter of 480 mm, operates in the frequency range of 200 MHz and 2.7 GHz.

The ADFA 1 consists of a series of nine antenna elements radiating around an omnidirectional reference antenna. These nine antenna elements are measured in relation to the central reference antenna. The reference antenna can receive signals from all directions over the entire frequency spectrum covered.

The ADFA 1 performs a direction-finding measurement independently of the elevation angle from which the signal originates, thus optimizing the reliability of tmeasurement results.

The combination of antennas, phase shifters and complex algorithms allows, according to Narda, the ADFA 1 to perform accurate measurements automatically using a single-channel receiver. To do this, the phase difference is measured between the antenna elements. The larger the gap between the antenna elements, the more accurate and stable the results will be.

In practice, the ADFA 1 can be fixed to the roof of a vehicle using a magnetic foot. This does not require vehicle modifications or drilling. It is no longer necessary to use correction tables depending on the vehicles used. For other applications, the ADFA 1 can also be mounted on a tripod to detect interference in stationary mode.

For the exact reading of the source of a signal on site, Narda offers a portable antenna that can also be used with the SignalShark signal receiver.