HIGH DATA RATE MODULATORS FOR EARTH OBSERVATION SATELLITE DATA DOWNLINKS

摘要

This paper reports on the design and performance of a High Data Rate X-Band Downlink Modulator developed at Tesat for use on earth observation satellites. This Modulator employs hard keyed QPSK modulation and is outstanding because of its high date rate (up to 700 Mbps), carrier frequency flexibility (8.025 MHz to 8.4 MHz in steps of 5 MHz) and low mass & power budgets. The paper provides also an outlook to future earth observation downlink data transmission requirements. Adequate realization concepts and first measurement results are presented for 8PSK X-band and Ka-band downlink data modulators.