Component for differential signal receiver for spectra spread by direct sequence - includes first correlator having applied signal at entry and pseudo-random sequence with second correlator to retard data

摘要

The component is located in a receiver of an intermediate frequency stage, and includes a filter (20), an amplifier (22) with gain control circuit (26), two amplifiers (34,36) for mixing (38) in the gain control circuit (40). The component is inserted between the amplifier (22) and the amplifiers (34,36) and has a coupler (62) of 3 dB. At one entry and two outputs (51,52) is a surface wave acoustic device (64), which has a first line with an entry transducer (TR1) and a first correlator (C1) delivering a signal (S1) and a second line with a transducer (TR2) and a second correlator (C2) delivering a signal (S2) . The second correlator is shifted w.r.t. the first to cause a retardation of the signal S2 to S1. The signal (E) of the intermediary frequency is split in two by the coupler (62). Two identical signals (E1,E2) are created with equal power. These two signals are filtered by surface acoustic wave filters. The exit signals (51,52) are identical but one is retarded by time T by the relationship S2 (t) = S1 (t-T). USE - Spread of spectra signal with retardation of signal for use in radio communications particularly military.