X頻段發射機

X-band Transmitter

X頻段發射機功能為下傳福八衛星之光學遙測酬載影像資料到地面站，其性能與設計特色包含基頻信號產生器採用現場可編程輯閘陣列設計、調解為4D-TCM 8PSK、差分編碼、CCSDS資料格式、下傳位元速率可選擇其最大達每秒600百萬位元、採用15瓦氮化鎵固態功率放大器、射頻頻寬為300MHz。

The function of X-band transmitter is to downlink FORMOSAT-8 optical remote sensing instrument (RSI) image data to ground station. The performance and design features include FPGA-based baseband signal generator, 4D-TCM 8PSK Modulation, differential encoding, CCSDS (Consultative Committee for Space Data Systems) data format, selective downlink bit rate with 600Mbps in maximum, 15W GaN solid state power amplifier with 3W output power and 300MHz RF bandwidth. The bit error rate achieved is not greater than 10-9. Regarding space radiation, the single event effects (SEE) are mitigated by delicate design of over-current protection and triple module redundancy with majority voting. All EEE parts are industry grade, auto-grade or military grade instead of high costed space-grade parts. Before flight and operation in orbit, it will go through a complete ground test including performance, reliability, and radiation.