A separate, but fully integrated active monitoring antenna gives high sensitivity omni-directional coverage on the same axis as the DF antenna, without interfering with the DF array.

The full-size elements on all bands give excellent DF sensitivity. Ultimate angular resolution for strong signals is well under 1° for most of the frequency range. Dipole elements provide good cross-polarisation rejection. They also give fair performance for signals arriving from up to 15° above or below the horison.

The integrated monitoring antenna is in two bands, mounted above the Band C & D DF antenna module housed in the radome. Each band of the monitoring array is amplified at the top of the cable, and passively combined to give continuous coverage over the frequency range 20 MHz to 6 GHz, with a single output connector.

This DF antenna is designed to be usable with either a 5- or 2-channel phase-sensitive receiver and correlative algorithm. Characterisation of the antenna can be performed on request.