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International audienceAccurate system level simulation is indispensable for efficient RF communication system design. However system level models of nonlinear circuits are today very limited by their inability to handle nonlinear memory effects. The paper describes a new approach of system-level modeling which accounts efficiently for nonlinear envelope memory effects of wideband amplifiers, multipliers and mixers

International audienceAn improved behavioral modeling technique for high power amplifiers with memor

The Public-Private-Partnership between ESA and Airbus Defense and Space (Germany) has created the European Data Relay System (EDRS), which is operational since 2016. The joint teams are running the Phase B of the globalisation of the European Data Relay System (EDRS) with an addition to the programme called EDRS Global (former GlobeNet). EDRS Global is planning to increase the capacity of EDRS by adding a geostationary data relay payload, called EDRS-D, over the Asia-Pacific regionin cooperation with Airbus DS partner JSAT (Japan). The heart of the system will be multiple laser terminals, based on TESATs upgraded design, featuring also a dual wavelength capability (1064 nm and 1550 nm) to serve more customers at the same time. The 1550 nm capabilities will be implemented in a cooperation between Airbus and TESAT (Germany), and NEC (Japan). The evolution of the service will also aim for security sensitive user missions, including RPAS missions. The Laser Communication Technology on-board EDRS-D will be the starting point for the world's first global laser based network in space, providing Global Secure Quasi-Real-Time-Services at Gigabit per second speed back to Europe by connecting its EDRS GEO nodes (EDRS-A/-C and EDRS-D) over 80,000 km distance by the means of optical communication. The paper will provide details of the project and information about the latest status.

This paper describes a fast envelope-tracking circuit capable of 10 MHz (up to 17.5 MHz) bandwidth based on RF GaN switching devices and 50 MHz switching frequency. The efficiency of the VHF converter is 84% to 90% which is comparable to a conventional DCIDC converter for spaceborne application. A demonstrator has been built and mated with a RF GaN HEMT output stage. The CII measurement for lO-12W RF output power close to saturation show a linearity improvement by 5-8d8 and an efficiency improvement of up to 8 points when compared to the case of no tracking circuit.