The stationary phase method calculating amplitude modulation for a pseudo random signal with a small side lobe level of correlation function

摘要

For integrals with fast oscillation of the subintegral function dominating contribution provides the region, where a velocity of changing phase is small. The point, where velocity of changing phase equal zero names the point of stationary phase. This method originates from the 19th century, and is due to George Gabriel Stokes and Lord Kelvin [1]. Synthesis of nonlinear frequency modulation for rectangular envelope was executed in [2, 3]. At last years, there is increasing interest to usage pseudo random signals (PRS) in meteo radars [4 - 6]. The synthesis of a pseudo random signals with super small side lobe level (SLL) of a correlation function were executed in [4,5]. At these jobs are used PRS with rectangular envelope and small SLL of correlation function (CF) for a matching filtration. One is the most important questions for the meteo radars is electromagnetic compatibility [7]. The usage of PRS with an amplitude modulation (AM) helps to obtain as super small SLL of CF, as a very small parasitic emitting in a spectrum domain. At this article the stationary phase method is used for synthesis of an amplitude modulation of pseudo random signal. For compression ratio 1000, correlation function of pseudo random signals has SLL of CF 90 - 120 dB and parasitic emitting spectrum has level - 120 - 150 dB.