X-Band Full MMIC QPSK Modulator with Direct Oscillator for the Spot 5 Earth Observation Satellite Payload

This paper presents a QPSK modulator equipment designed and qualified for space applications. It enables high data rate transmission for Earth observation satellites. The equipment is based on a full MMIC RF chain, including a MMIC QPSK linear vector modulator, and features a direct X band Local oscillator (LO). Data rates up to 2×150 Mbits/s and RF output power up to 6 W for LO frequencies between 7.2 and 8.5 GHz can be achieved. Design description and Qualification Model performances are provided in this paper.