DF-A0257 : An innovative design to balance performance and size

Alaris Antennas, a leader in the design and customisation of direction-finding antennas, is pleased to announce the release of our new sensor, the DF-A0257.

The DF-A0257 forms part of Alaris Antennas’ compact, tactical, DF antenna portfolio. Our DF products normally deploy as a COMINT sensor into man portable or vehicle platform COMINT solutions. These portable systems could be applied as on-the-move or on-the-halt solutions.

During the design of the DF-A0257, special attention was given to the form factor. The physical form factor of the product was kept as small as possible, due to market sentiment and operational requirements as dictated by end users and operators of the above mentioned solutions. The antenna does not rely only on amplitude information, as is the case with limited in performance solutions employing 4 directional elements.

When an operational scenario dictates an on-the-halt deployment, then the DF-A0257 product could be augmented with a frequency range extending array, which comfortably extends the frequency range down to HF frequencies as with our DFS-A0245.

The sensor supports an extremely wide frequency band for its size, i.e. 20 MHz to 6000 MHz and offers various communication interfaces as well as options for an integrated compass, GPS, INS and onboard storage.

Alaris Antennas offers the DF-A0257 in Watson-Watt configuration or as a 4-channel correlative system. Unsurpassed DF performance is obtained when applying the antenna with a CAL table as part of a CIDF system, compared to solutions relying on amplitude-based information only, which is of the same size.

The DF-A0257 concept stemmed from the development of a similar product within the same portfolio, the DF-A0254, which was developed for military and C-UAS clients where low SWaP forms part of their critical requirement.

The DF-A0254 provides DF functionality within the 400MHz to 6000MHz frequency range. With wide acceptance of this version development of a sensor of the same physical profile was the next step. However, the sensor had to support a much lower operational frequency due to different threat profiles.

Typically, an improvement to the low frequency performance of an antenna would necessitate a substantial increase in the overall size of the antenna.

With an innovative design, the DF-A0257 can achieve good DF performance down to 20MHz (20 times lower than the DF-A0254) whilst maintaining the same form factor as the DF-A0254.

The DF-A0257 range includes 20dB gain low noise switchable amplifiers on all DF channels which provides good sensitivity, across the entire band. Such amplification functionality could be activated or deactivated depending on the operational use-case.

Examples of where it can be used as a COMINT sensor are listed below with different DF approaches described in further detail in this blog.

• Military: such as the detection of threats, location and movement detection of enemy transmitters and detection of enemy standoff jamming assets.
• Search and Rescue: location of RF search and rescue beacons.
• Science: the tracking of animals in their environment.
• Radio monitoring: the location of sources of interference and of illicit transmitters