LOW-COST ELECTRONICALLY STEERED ANTENNA AND RECEIVER SYSTEM FOR MOBILE SATELLITE-COMMUNICATIONS

The design, construction, and basic characteristics of an electronical ly steered, adaptive phased array antenna for land mobile satellite Co mmunications are described here, The antenna system includes an array of six microstrip stacked patch antennas, each one connected to an RF channel, which include a monolithic microwave/millimeter wave integrat ed circuit (MMIC) low noise amplifier and a commercial silicon monolit hic I-Q modulator, A six-way microstrip combiner adds the six channels so that the resulting signal is introduced in a global positioning sy stem (GPS) receiver, constructed with two commercial application speci fic integrated circuits (ASIC's), This receiver has a PC interface whi ch include control boards, specifically designed for this application, that allow the setting of the amplitude and phase of each RF channel, Acquisition and tracking algorithms have been programmed in C-languag e for working in real time using as input data the signal levels provi ded by the receiver.