Narda Safety Test Solutions ADFA 2 automatic direction finding antenna

The ADFA 2 is Narda Safety Test Solutions’ second automatic direction finding antenna, with a frequency range that has been increased by more than three times. When connected to Narda’s powerful real-time receiver, the SignalShark, the device can precisely localise signals between 10 MHz and 8 GHz.

The product delivers stable measurement results in seconds — it is insensitive to reflections. Its wide frequency range means that direction finding at low and high frequencies is covered equally. Compact and universal, it combines a broad spectrum with the minimum outlay of equipment. This makes the device suitable for mobile network providers and regulatory authorities, as well as for military applications.

For applications on the move, the unit is easily attached to a car roof with the aid of its magnetic base; a single cable links it to the SignalShark. It delivers precise results even without the vehicle correction tables that are usually required. While still on the move, the measurement technician can superimpose a heatmap on a stored map on the SignalShark display as well as view the found direction. The localisation software in the device automatically indicates where the interference source is most likely to be located.

An array of nine antenna elements (dipoles) are arranged on a flat plane with a central omnidirectional reference antenna, which allows the measurement technician to observe the signal spectrum during direction finding. The principle of automatic direction finding using single-channel receivers is based on the phase difference between the antenna elements. The nine dipoles are measured against the central reference antenna — the greater the distances between them, and thus the detected phase difference, the more reliable the bearings.

As a result of the extended frequency range at both ends of the scale, there is a lower plane for the range from 10 to 200 MHz and an upper one for the range from 2.7 to 8 GHz. These additional planes mean the device weighs 6.5 kg, with a diameter of 480 mm.