Performance Analysis of Coherent CSAS Imaging using Bandpass Signals

In this paper, the applicability of coherent processing of bandpass signals to increase the resolution is verified and point spread functions (PSF) using bandpass and lowpass signals are investigated and compared. Theoretical and simulation results show that compared to lowpass signals, PSF of bandpass signals provides a much higher resolution. However, two main problems in its PSF should also be noticed: 1. Relatively high side lobes appear in the PSF and it is close to the main lobe; 2. The PSF using bandpass signals is sensitive to scatterer location deviation from the pixel centers.