PHASE-BASED DIRECTION FINDING METHOD Russian patent published in 2013 - IPC G01S3/14 

FIELD: radio engineering, communication.

SUBSTANCE: phase-based direction finding method involves receiving signals at two antennae spaced apart by a distance d, amplifying and limiting the signals; for a first phase channel, the input signal mixture from the first antenna is multiplied with a heterodyne signal; a signal mixture at an intermediate frequency is separated; the separated signal mixture is again multiplied with a signal mixture from the second antenna; a signal mixture at a second intermediate frequency is separated based on mutual sideband components, the central frequency of which is equal to the heterodyne frequency; heterodyne frequency is rejected; similar signal conversion is carried out for the second phase channel, the difference being that the heterodyne signal is phase-changed by π/2 so that the direction finding characteristic has odd symmetry; mutual combination frequencies are then picked up at the output of each phase channel and for each pair of sideband components at the same frequency, the phase difference Δφ_vλ is measured, wherein the signal level at the filter output higher than a predetermined threshold indicates the presence of a sideband component.

EFFECT: high frequency resolution during simultaneous reception of radio signals from several radio-frequency sources, high reliability and accuracy of determining direction of a signal source.

3 cl, 1 dwg