Narda Safety Test Solutions ADFA 1 antenna

Narda Safety Test Solutions has developed an automatic direction-finding antenna (ADFA) that delivers stable results quickly. Insensitive to reflections, it precisely determines the direction of a detected signal.

When coupled with the powerful SignalShark real-time receiver, the system is suitable for automatic direction-finding of signals in the frequency range from 200 MHz to 2.7 GHz. As well as for cellular network providers and the military, it is primarily aimed at PMR and BOS radio operators with applications that involve safety and security.

At the heart of the product is an array of nine antenna elements around an omnidirectional reference antenna optimally arranged to achieve stable measurement results. The reference antenna allows test engineers to observe the spectrum at the same time as direction-finding. The principle of automatic direction-finding for a single-channel receiver is based on the measurement of the phase difference between antenna elements. The nine antenna elements are measured against the central reference element. The greater the distance between them and the greater the recorded phase difference, the better the bearings.

As well as stationary applications, the antenna can be attached to the roof of a vehicle using a magnetic mount. When connected to the SignalShark, a bearing cycle takes just 1.2 ms and achieves an accuracy of up to 1° RMS (typical). Along with the simple display of the determined direction, the receiver can also overlay a heat map on a stored map. The powerful localisation software on the SignalShark can thus show the most likely location of the interferer directly on the screen during mobile operation, all in real time. A handheld antenna can be used with the receiver to determine the exact location of a signal source over the final few metres, so that the test engineer can enter a previously localised building in order to determine the exact room where the source is located.