A New Baseband Linearizer for More Efficient Utilization of Earth Station Amplifiers Used for QPSK Transmission

The principles and applications of a new baseband linearizer are described. It is demonstrated that, with the use of our linearizer, significant improvements in the effective radiated power of the earth station high-power amplifier can be attained. In a particular example, the characteristics of the recommended INTELSAT V satellite simulator model are used. For the 120 Mbit/s QPSK transmission system operating in a complex interference environment, we show that with the new iinearizer the earth station high-power amplifier may be operated almost in full saturation while meeting the current INTELSAT requirements. This is a significant improvement in power utilization efficiency. Similar improvements could be obtained for small digital singlechannel-per-carrier earth stations.