Consideration of nonlinear effects in different receiver architectures for use in passive radar systems

Abstract

In passive radar systems the high dynamic range between the received reflected signal and the received signal of neighboring strong transmitters as well as the direct signal causes high demands on the receivers. Since a real receiver never shows a perfect linear characteristic, this always implies nonlinear effects. Consequently, the in the receiver generated interfering signals lead to a reduced total sensitivity. According to the intensity and spectral distribution of the input signals, intermodulation noise is produced. This paper shows a consideration and an estimation of nonlinear effects in different receiver architectures, depending on various measured input spectra for passive FM radar.