The need for radar systems to autonomously adapt to their environment is growing along with the desire for utilizing more bandwidth. However, the RF spectrum will only continue to become more crowded. A cognitive radar system with the functionality to sense and avoid other RF signals in the radar's frequency band of interest is presented. In order to meet this challenge, the radar system developed is capable of sensing and avoiding time varying signals that change on the order of tens of milliseconds. This paper outlines the cognitive radar system design with an emphasis on system timing. The paper also describes a hardware implemented test bed for analyzing the cognitive sense and avoid algorithm with various communication signals as interference.