Demonstration of two-way Extremely High Frequency (EHF) satellite communication (SATCOM) using submarine-survivable phased arrays

U.S. submarines are faced with the challenging dilemma of addressing the need for higher data rate satellite communications (SATCOM) without significantly increasing the size of the SATCOM antenna. The planar form factor of phased array technology, along with the ability to steer beams electronically, has led to submarine antenna concepts that can simultaneously improve performance, utilize the submarine sail volume more efficiently, and minimize the impact to platform stealth. Through technology development under the Office of Naval Research (ONR), submarine-survivable phased arrays that address EHF SATCOM have been fabricated, tested, and delivered to the Navy by Boeing Phantom Works. The Naval Undersea Warfare Center has recently performed notional system integration and testing of these arrays. Q-band (44 GHz) uplink- and K-band (20 GHz) downlink-phased array antennas were tested successfully using both the military strategic and tactical relay (MILSTAR) and ultra high frequency follow-on (UFO) military satellites. The antennas were integrated with the Raytheon Follow-On Terminal (FOT) for full-duplex SATCOM testing. Full-duplex data rates of up to 64 kbps were attained using the phased arrays under optimal weather conditions. Bit error rate testing (BERT) was performed with no bit errors recorded. Initial tests were performed with the phased arrays mounted on a stationary platform; subsequent testing involved integration of the phased arrays into a notional housing atop a submarine mast. Notional mast testing included simulated ship motion using a six-axis motion table that is located on the roof of the Naval Undersea Warfare Center Division Newport's (NUWCDIVNPT) Building 68 (B-68) with support from the Submarine EHF Satellite Communication Integration Facility (SESIF). Half-duplex testing was also performed using a fiber optic (FO) link to carry both the control and radio frequency (RF) signals for the downlink-phased array on a single FO cable. This paper will provide an overview of the array technology and will describe the configurations and results of SATCOM testing.