АДАПТИВНОЕ УСТРОЙСТВО ПРЕДЫСКАЖАЮЩЕЙ ЛИНЕАРИЗАЦИИ ДЛЯ БОРТОВЫХ РАДИОПЕРЕДАЮЩИХ УСТРОЙСТВ.

Abstract

The improvement of energetic and spectral characteristics of the satellite transmitters which act in the harsh space environment with the help of the predistortion linearization becomes more and more actual task. The proposed adaptive predistortion device is based on the correlation evaluation of the nonlinear distortion level at the output of the power amplifier. The device allows to provide more effective linearization in the conditions with changing characteristics of the satellite transmitter within the lifetime of the satellite at the orbit in difference to the systems with advance tuning. The proposed technical solution has a higher reliability and simplified technical implementation in comparison with the analogs due to lack of the preliminary analog and digital processing of the RF signal. The simplified algorithm which requires lesser logical capacity in the digital microcircuits than conventional adaptive algorithms was developed for the modeling of the adaptive predistortion device. The proposed algorithm of changing the parameters of the predistortion linearizer requires less mathematical calculations within one iteration cycle, which is based on the determination of the cross-correlation function gradient rise direction. The obtained results of proposed predistortion linearizer modeling show that the process of two-dimension adaptation based on the developed algorithm is monosemantic and leads to the recovery of the linearizer’s non-linear characteristics optimal tune. The adaptation process leads to the lowering of the intermodulation distortion at the output of the power amplifier in a few adaptation cycles. It is worth noting that the process of the optimization and selection of the two parameters of the predistortion linearizer in the amplifier flows the same way whatever if the analog of digital implementation of the linearizer is used.