Abstract: The radar antenna, monopulse comparator network, and mixer simulator is a al-time computer controlled simulation of the antenna, monopulse comparator network, and rf mixer of tracking radar systems which normally transform the angle of arrival of incoming signals into amplitude and phase modulations on intermediate frequency sum and difference channel signals. The simulator produces appropriately modulated intermediate frequency (IF) sum and difference channel signals as a function of computer derived spatial angle information. These IF signals correspond to the radar-hardware-derived sum and difference channel IF signals.