Consolidated Apertures with Co-site Interference Reduction in the Frequency Range 2 to 30 MHz

Zeger-Abrams Inc. (ZA) proposes the use of active feedback cancellation in both the shipboard HF (2-30 MHz) transmitter and receiver systems for cosite interference suppression. The proposed approach supplements consolidation of multiple HF transmit (TX) signals onto two existing TX antennas, and multiple HF receivers fed from one existing receive (RX) antenna. ZA"s approach allows for RX sensitivity down the level limited by external quasiminimum noise and intermodulation products produced by"rusty bolts"in the topside ship structure when multiple high-power HF signals are being transmitted. TX output insertion loss will be greatly reduced from that in present systems. System changes required because of changes in TX or RX frequencies will automatically be rapidly accommodated.