A Rugged Synchronization Scheme for Large Aperture Antenna Array

Large Aperture Antenna Arrays are increasingly becoming important. This is primarily because of the need to transmit high power of the order of hundreds of kilowatts. This necessitates the usage of thousands of Transmit Receive Modules (TRMs) which are in turn controlled by hundreds of Digital LRUs arranged in a series parallel configuration across multiple levels of hierarchy. This arrangement calls for a rugged synchronization scheme to be implemented in the antenna so that it can be ascertained that all the TRMs at the lowermost level in the hierarchy play the same forward dwell which is transmitted from the Master Timing Generator Module. Existing trigger-based synchronization schemes or carrying separate clock lines across each level of the hierarchy is ruled out in this case because of the small size of the modules which in turn, restricts the number of I/O lines which are carried across each level of hierarchy. Synchronization is also required for the antenna to handshake with other sub-systems of the radar. This paper discusses such novel and rugged synchronization schemes with minimum hardware complexity which were designed, implemented, tested and successfully field proven.