The present invention relates to a device for auto-adaptative direction and polarization filtering of radio waves received on a network of aerials coupled to a receiver.
The invention is applied in particular to the construction of an interference elimination device for receivers of electromagnetic waves travelling through the HF ionospheric channel.
It is known that a tactical high frequency reception aerial must in particular enable any user to establish radio connections with various transmitting stations, and to simultaneously hear the transmissions from the other users of the high frequency channel.
Bearing in mind the congestion of the high frequency channel, the receiver must be able to reject the signals coming from sources of interference, be they intentional or not.
However, the known tactical high frequency adaptative aerial networks, generally formed from several suitably spaced vertical whips, do not enable exploitation of the polarization of the ionospheric waves. Whilst the performance levels expected from an adaptative aerial formed from three orthogonal dipoles, which does not have the shortcomings of the whips, are described in an article by RTE COMPTON entitled "The tripole antenna: an adaptative array with a full polarization flexibility" (IEEE trans antenne and propagation. Vol.: AP 29 No. 6 Nov. 81), the aerial which is described therein has the tactical disadvantage of having to be placed at the top of a mast so that the radiation patterns of the horizontal dipoles are correct. Moreover, as it is technologically very difficult to suppress the high frequency currents circulating in the external parts of the coaxial cables connecting the dipoles of the aerial to the receiver, the performance levels expected of this aerial configuration are, in practice, not obtained.