Co-Site Interference Mitigation in Phased Arrays

The available space for antennas within a submarine sail is extremely limited. To achieve the desired multi-frequency capability for future submarine communications systems, phased array apertures will need to be collocated within a single housing. The resulting close proximity of transmit and receive antennas and the requirement for full duplex communication lead to a challenging electromagnetic interference (EMI) problem. The EMI is especially severe at X-band frequencies where the X-band transmit array and the X-K-band receive array both operate simultaneously. Fortunately, there is some room to physically separate the X-band transmit array from the X-K-band receive array. A choke structure and/or patterned absorber inserted into the space between these two arrays can reduce the X-band EMI while passing through signals from the higher frequency transmit arrays (Ka-band and Q-band) that share the same space. Toyon has extensive experience designing chokes and patterned absorbers tailored to mitigate EMI with a minimal thickness and weight. Toyon proposes to use this experience to investigate the use of an X-band choke/absorber structure that is transparent to signals in the Ka-Q bands.