Synthesis of a filter of phase-domanipulated signals with a minimum side-lobe level

The article shows the possibility of detecting airborne objects using a model of a vertical sounding radar cluster (VZ radar) with field tests and an assessment of the achievable detection characteristics. In the layout, a 13-element Barker code was used as a probing signal. The received signal is compressed in the receiver’s matched filter, resulting in sidelobes around the main response. The number of side lobes is N - 1, where N is the number of discretes of the PCM signal. The side lobes have the same amplitude and triangular shape, and their level is N times less than the level of the main response [1, 2]. The presence of side lobes is undesirable due to the possible masking of a signal reflected from a target with a small effective scattering area (ESR) by side lobes of signals reflected from a target with a large ESR, which is often observed in the area of reflections from local objects. Thus, there is a risk that a target with a low RCS will not be detected by the receiver. In addition, side lobes contribute to an increase in the noise level when a target is detected in the area of reflections from local objects, hydrometeorological formations, etc. With this in mind, in the layout, to significantly reduce the level of side lobes, a side-lobe suppression device (SBSL) was developed and used using inverse filters [3]. The proposed UPBL uses inverse filtering with digital filters, due to which the side lobes of the radar pulse compressed in the receiver can theoretically be completely eliminated, and in the practical case there is a significant suppression of the side lobes.