Analysis of the spectrum transform for narrow-band signal passing through nonlinear section of a digital radar receiver

Abstract

In this paper, with the analytical method, the problem of unexpected bandwidth occupying is investigated firstly when a narrow-band signal passes through the inertialess nonlinear section of a digital radar receiver. Afterwards, the frequency aliasing that is caused by the digitalization is studied. To solve these two issues, the selection of the sampling frequency is of great importance. In this paper, a maximizing minimum arc-distance strategy is proposed, which is dependent on the frequency range of the signal. The arc-distance method is designed for optimizing the sampling frequency. Furthermore, with this method, the minimum arc distances between the frequency bands of the signal and the interferences can be calculated. The inter-band arc distances are important references for optimizing the transition bandwidth of the filter after the sampling and demodulation process.