A nonlinear device to suppress strong interfering signals with arbitrary angle modulation in spread-spectrum receivers

A simple device which almost completely eliminates strong constant-amplitude jamming signals irrespective of their bandwidth is described. Jamming signals having slowly varying amplitudes are also suppressed by this device which is connected in series to the receiver input and which offers the additional advantage that the receiver input level becomes almost independent of the received jamming power. Unmodulated CW signals, broadband FM signals, and spread-spectrum interferers with PSK or MSK spreading modulation are examples of suppressible jamming signals. The theoretical results are confirmed by measurements.