Direct-Conversion-To-Baseband for a Nonlinear FM Signal

摘要

In this report, we examine both nonlinear FM signals and a direct-conversion-to-baseband process in a radar application system. We generate a phase predistortion function which modifies the transmitted linear FM signal and synthesizes the desirable effect of a sidelobe weighting function. To avoid a mismatch in obtaining the in-phase and quadrature signal components at two separate processing channels, we directly convert a low IF signal to its baseband by a combination of sampling, filtering and decimation. A band-limited nonlinear FM signal with a low pulse compression ratio is considered and processed. The compressed signal is also obtained through a pulse compression filter matched to the transmitted signal. Nonlinear FM, Signal sampling.