METHOD TO IMITATE DOUBLE-FREQUENCY RADIO SIGNALS Russian patent published in 2013 - IPC G01S7/40 

FIELD: radio engineering, communications.

SUBSTANCE: method to imitate radio signals is designed for testing of tracking systems of pulse radar stations (RS). The entire cycle of imitation is divided into two time signals. During the first interval the pulses received from the RS are range-stolen. During the second interval two pulse sequences are generated, which are shifted in time and spaced by frequency. The time shift is arranged as slowly changing, for instance, in accordance with the harmonic law, at the same time harmonics for both frequencies have one and the same frequency, but are phase-shifted. The frequency separation is carried out in two stages: at first the shift is carried out by the value where ω_int - the first intermediate frequency of an RS amplifier, and then both pulse sequences - by the value δ, exceeding the pass band of the specified amplifier. To eliminate stable zeros of a direction-finding characteristic of the RS, the carrier phase in one of sequences is periodically changed relative to the other by 180 degrees, at the same time the phase of the slowly changing modulating function is varied.

EFFECT: increased imitating ability of a double-frequency radio signal.

4 cl, 7 dwg