AN/APQ-181

Description: The AN/APQ-181 was developed to meet the US Air Force requirements of a low probability of intercept radar for the B-2 stealth bomber. APQ-181's physical design provides two completely redundant radar sets, each consisting of antenna, transmitter signal, signal processor, data processor and receiver/exciter. In the event of a malfunction, this design architecture will continue to provide a fully functioning radar system.

In August/September 2004, the Northrop-Grumman as prime contractor awarded Raytheon a contract to provide an active electronically scanned array (AESA) antenna that will enhance the overall performance of B-2 bombers while minimizing the probability of enemy interception of the antenna radio frequency emissions. Each AESA antenna will consist of more than 2,000 two-channel transmit/receive modules. The B-2 Radar Modernization Program (RMP) has been valued at $600 million.