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This paper presents the design procedure and laboratory results for a baseband pre-distortion method. This design consists of 32QAM modulation in nonlinear satellite channel for DVB-RCS Earth Station Transmitters. It is concluded that by predistorion of modulation constellation in transmitters, we will be able to get an undistorted constellation at the output of satellite TWTA.We compare the BER performance of 32-QAM Modulation in predistotion and non predistortion cases. By utilizing the proposed method in a saturated TWTA, there is only 4dB difference between theory and simulated results. The simulation results of proposed method show that the eye diagram using PD is opened as 5 times. The laboratory results show 4-times improvement in the rate of opening eye diagrams for proposed method

In this paper, the design, fabrication, and measurement results of a two‐stage X‐band highly efficient 50 W power amplifier are presented. In the design approach, two 0.25 μm bare‐die GaN on SiC transistors, where one of them has the largest gate periphery on the market, are chosen. A considerably high saturated power gain of more than 20 dB and better than 40% power‐added efficiency (PAE) are achieved over the 10.9 to 11.1 GHz bandwidth. Modulated measurements demonstrate an average output power of 40 W with good linearity specifications. Thermal assessment from measurement results ensures transistors' durability.