Measurement/prediction comparison for K/sub u/-band MMIC active phased array for satellite communications

A 64-element experimental model for an active phased array has been built, with the active transmit modules implemented in MMIC (monolithic microwave integrated circuit) technology. A block diagram of the main components in the array system is presented. The transmit modules, which consist of 5-bit phase shifters, single-stage buffer amplifiers, 5-bit attenuators, and three-stage driver amplifiers were selected within predetermined performance bounds in order to satisfy the overall deviation limits allowed by the design. The authors present the measured results of the experimental model, which generated a number of shaped beams, as well as a number of scanned spot beams, within the global coverage area. Measured results for an array built to cover INTELSAT´s AOR (Atlantic Ocean Region) show good agreement with predictions, which take into account implementation margins that allow for amplitude and phase perturbations.<>