Eliminating radar interference - requires calculation of coefficients from in-phase and in-quadrature signals to cancel linearly combined signals

A radar jamming signal is eliminated by using auxiliary receiving antennas to pick up the signal and then combining these signals linearly. Coefficients are determined from the in phase and quadrature signals received at the antennas which will cancel out the combined signals. In an open loop digital anti jamming circuit, the in phase (I) and quadrature (Q) signals are obtained from Doppler filter assemblies (31, 32) prior to combination in a linear combining circuit (CL). The in-phase and quadrature signals are processed by a calculator (22) controlled by a sequence (23) so that the calculation phase is located at the end of the repetition period. The average values of the coefficients (alpha-bar, beta-bar) are determined by a second calculator (25) and applied to the linear combiner (CL) during the following repetition period. L'invention concerne un dispositif d'élimination de brouillage dans un radar comportant deux antennes de réception A1 et A2 et délivrant deux signaux en quadrature I1 et Q 1 relatifs à l'antenne A1 et deux signaux en quadrature I2 et Q2 relatifs à l'antenne A2 . Le principe de l'invention consiste à fournir deux signaux I0 et Q0 exempts de brouillage en effectuant les combinaisons linéraires suivantes :