L-band stepped frequency noise SAR on the basis of Arbitrary Waveform Generator

Current paper deals with radar design obtained by combination of two approaches: stepped frequency radar and noise radar for the purposes of SAR imaging. Motivation for such combination is overcoming of drawback of noise radars such as necessity of using fast ADCs in order to provide high range resolution and drawbacks of stepped frequency radar such as presence of range ambiguities, low electromagnetic compatibility, high probability of interception and low interference immunity. The proposed stepped frequency noise radar approach consists in generation of narrowband sounding noise signal and stepped-like variation of its central frequency. The reception is to be done by analog mixing of radar return with sounding signal, filtering and sampling by a relatively low speed ADC. This solves problem of lack of ADCs with both high depth and sampling rate which leads to difficulties in design of high performance noise radars using conventional approach. The aim of the paper is to describe the approach, to present results of its experimental investigation and to confirm possibility of using this approach for SAR imaging.