Mitigation technique for High altitude Electro Magnetic Pulse (HEMP) for GPS receiver

The Global Positioning System (GPS) based navigation system for air borne application has RF receiver frontend exposed to external Electromagnetic Pulse (EMP) attack threat due to direct connectivity to GPS antenna. Damage to these LNAs or following digital circuitry and disruption in received data may cause catastrophic failure of the navigation system. A measurement study has been carried out to estimate the effect of EMP on GPS active antenna. Mitigation technology has been successfully developed and integrated at the front end without deterioration in the receiver sensitivity. This paper presents design of protection circuitry, RF and noise performance, EMP Test methodology and test results as per MIL-Std-461D for protected and unprotected systems.