Through-the-wall radar imaging is of value in several civilian and defense applications. One of the challenges in
through-the-wall radar imaging is the strong wall reflections which tend to persist over a long duration of time.
In order to image weak and close by targets behind walls, the wall reflections should be suppressed, or at least
be significantly alleviated. In this paper, we apply spatial filters across the antenna array to remove the spatial
zero-frequency and low-frequency components which correspond to wall reflections. The application of spatial
filters recognizes the fact that the wall EM responses do not significantly differ when viewed by the different
antennas along the axis of a real or synthesized array aperture which is parallel to the wall. The proposed
approach is tested with experimental data using solid wall, multi-layered wall, and cinder block wall. It is shown
that the wall reflections can be effectively reduced by spatial preprocessing prior to beamforming, producing
similar imaging results to those achieved when a background scene without the target is available.