Multistatic imaging techniques, such as Synthetic Aperture Ultrasound (SAU) or Plane Wave Imaging (PWI), offer several advantages in terms of image quality for diagnostic ultrasound imaging. However, the vast amount of data generated by these methods can be challenging to process and store. To address this issue, various compression techniques have been developed. In this work, we propose a compression method based on a physical approach utilizing evanescent wave components in the radio frequency (RF) data. The basic idea behind our approach is to eliminate the higher frequencies in the data that are no longer necessary, due to the limited spatial sampling frequency. By doing so, we can reduce the amount of data without sacrificing noticeable amounts of image quality, as shown by simulation results. An additional advantage of our approach is that no decompression steps have to be conducted if the image reconstruction algorithm operates in the spatial frequency-domain.