(ADFA-1) Automatic Direction Finding Antenna

(ADFA-1) Automatic Direction Finding Antenna

New Automatic Direction Finding Antenna
- Signalshark ADFA 1 (Frequency range 200 MHz to 2,7 GHz)

Automatic DF Antenna: It is often necessary to locate the position of a signal transmitter once the signals have been detected and analyzed. SignalShark supports the new Automatic Direction Finding Antennas (ADFAs) from Narda, allowing quick and reliable RF signal localization.

  • Maintaining PMR and mobile networks by finding transmitters and interferers fast and reliable
  • Managing frequency bands
  • Monitoring communication at borders
  • Protecting areas and signal reconnaissance

Situation awareness of the RF spectrum while DF.
A central monopole is used as a reference element for DF and as an omnidirectional monitoring antenna. This allows monitoring of the adjacent signals around the signal of interest using a Spectrum View while DF

High and reliable localization quality even in urban areas with reflection.
Due to the large antenna aperture of 380 mm and the nine dipole elements, the ADFA has a high DF accuracy. Together with the heat map localization algorithm, which runs directly on SignalShark, the localization results are very reliable, even in urban areas with lots of reflections.

Integrated electronic compass and GNSS receiver.
For easy and fast alignment, the ADFA is provided with an electronic compass and a GNSS receiver module.

Azimuth and Elevation data for high-end DF performance.
The bearing results of the ADFA contains azimuth and elevation information. This makes a big improvement of the localization for transmitters, that are in a different plane than the antenna itself.

Bearing of very short signals.
The ADFA works very fast and takes down to 1.2 ms for one bearing. Thus, it supports reliable results even for very short or pulsed signals like Push-to-talk (PTT), telemetry and hopping signals.

Fast and easy setup.
No additional laptop necessary Simply connect the ADFA to SignalShark and start bearing. The ADFA is controlled and powered by SignalShark. Even the localization algorithm together with an Open Street Map based heat map visualization is integrated in SignalShark. Magnetic mount adapter for vehicle us or Tripod for semi-static use.

Product Features

Built-in phase shifter and switch matrix
Direction finding method ›correlative interferometer
Bearing uncertainty: 1° RMS (typ.)
Built-in electronic compass
Built-in GNSS receiver with antenna and PPS output
Diameter: 480 mm
Automatic DF-Antenna for Mobile Operators, 200 MHz to 2.7 GHz
RF-Cable, 9 kHz - 8 GHz, N to SMA, 50 Ohm, 5 m*, "Low-Loss"
ADFA Vehicle Mounting Kit
Hard case for automatic DF Antenna
Option, Automatic DF antenna control, Bearing View


Frequency: range 200 MHz to 2,7 GHz
Dimensions: 219 mm x 480 mm (8.62ʺ x 18.9ʺ)
Weight: 5.6 kg (12.3 lbs)

Product description

Full automatic DF System
SignalShark supports ADFAs (automatic DF antennas) from Narda. An ADFA translates signals from several antenna elements into a single channel DF signal. The ADFA is controlled by SignalShark, which automatically determines bearings, based on the single channel DF signals. Measurement results can be bearings, as well as omnidirectional level and spectrum values. Additionally SignalShark calculates the statistical distribution of bearing lines and provides transmitter localization visualized live as a heat map.

The ADFA can be used with a tripod, can be mounted to an antenna mast or can be attached to the roof of a vehicle via a magnetic mount adapter.
Fast automatic direction finding

In an ADFA, there are several elements of antenna arrays, an omnidirectional reference antenna, four phase shifters, a summing stage and a switch matrix. SignalShark controls and synchronizes the switch matrix with its extremely fast internal measurement unit. A complete bearing cycle can be as short as 1.2 ms. During each bearing cycle the omnidirectional channel power and the spectrum are measured. This makes it possible to monitor changes in the signal level or spectrum concurrently with the bearings. Thus, you can optimize your bearing settings to the signal of interest and monitor the adjacent channels.

Built-In transmitter localization
SignalShark simplifies localization of transmitters by autonomously evaluating all the available bearing results and plotting them on a map. It uses a statistical distribution of bearing lines that represents the uncertainty in the bearing. The result is a map on which the possible locations of the transmitter are plotted and color-coded according to their probability. Red corresponds to a very likely and blue to a very unlikely transmitter position. SignalShark also draws an ellipse, which marks the area where the transmitter has a 95 % probability of being located, and its center is the estimated position of the transmitter.

When bearings are taken under non-ideal conditions, such as in an urban environment, the uncertainty in the bearings is much more dependent on the environment than on the ADFA. Nevertheless, if enough bearings are taken from enough locations, the localization algorithm of SignalShark will generally result in a convergence on the actual location of the transmitter, even in urban surroundings. To speed up and optimize the localization process, an ADFA can be attached to the roof of a vehicle to take random bearings in the suspected area. This allows fast and reliable localizations even in challenging environments.

ADFA 1 Datasheet