Development of a low cost and high data rate X-band transmitter for micro-satellite applications

This paper presents a low cost and high data rate downlink transmitter at X-band for micro satellite remote sensing applications. The 2W X-band transmitter is developed for 412.5Mbps data rate with 8PSK/4D-TCM 8PSK modulation to satisfy the LEO satellite link budget requirement at 561 Km and BER performance of 10e-11. The proposed X-band transmitter consists of the digital modulation baseband signal generator and the up-converter with 2W RF solid state power amplifier (SSPA). A high data rate QPSK/8PSK baseband signal generator with high efficiency, small distortion, and digital filters is developed in FPGAs. An innovative concept for NSPO micro-satellite X-band downlink system development is the 2W RF solid state transmitter combined with a high gain antenna and pointing mechanism. Both the output power spectrum and the EVM for 450 Mbps 8PSK signal at 8200 MHz center frequency have been demonstrated separately. The performances are prominent for the micro-satellite data downlink system applications.