A need for very high probability of detection in modern passive Electronic Combat (EC) systems has stimulated development of ever-wider receiver bandwidths. As the receiver bandwidths increase, some portions of the RF spectrum will begin to have a probability of signal overlap approaching unity. Wideband receivers, when operating in these environments with increasing signal threat densities and new modern modulation techniques, must incorporate computationally intensive algorithms within the receiver architecture to ensure reliable performance. Acousto-optic processing subsystems offer a real-time solution to several of the computationally intensive signal processing functions required in wideband EW systems. Two such acousto-optic subsystems that are being developed by DARPA through the Naval Research Laboratory will be discussed in this paper: Channelization and Direction Finding.