An L Band Phased Array Antenna for Marine Satellite Communications

Commercial marine satellite communications over the Inmarsat system has as a rule seen a predominance of dish antennas used in shipboard terminal applications. A notable exception has been a phased array built by Chalmers University of Technology (Ref.1). In any case the shipboard antenna must track satellites in the presence of severe ship dynamics. For dish and fixed array antennas this requirement leads to the widespread use of relatively elaborate and costly inertial stabilization mechanisms. To eliminate the need for mechanical stabilization an electronically steered phased array antenna is proposed. The antenna is conceptually similar to the Chalmers antenna; however, circuit implementation is radically different. Two flat plate arrays are used. An array comprises 64 radiating elements each independently driven by a 3 bit phasor. To minimize component inter-connects and assembly cost, radiating elements, phasors and corporate feed network are implemented in microstrip on large (0.9m × 0.9m) circuit boards in a multi-layer laminated assembly.