Tomoya Fukami

High speed downlink system for small satellite and high-efficiency x-band GaN SSPA

A high-speed downlink communication system is required to meet various applications for nano/small satellites. The purpose of this research is to develop a high-data-rate X band downlink system with low power consumption. A high efficient RF circuits using GaN-HEMT SSPA and low power consumption digital circuits were important. We developed over 300Mbps with occupied BW150MHz, RF power 2W, power consumption 20W, mass 1.4kg.

High-efficiency X band GaN power amplifier for small satellite downlink system

A high-speed downlink communication system is required to meet various applications for small satellites. The purpose of this research is to develop a high-data-rate (typically over 300Mbps) communication system. Generally, the operation at nonlinear region provides high efficiency for a RF power amplifier. However the amplitude-phase modulated signal, which is an efficient scheme in term of frequency band, requires high linearity. In order to amplify amplitude-phase modulated signal for high data rate, a 2W X Band GaN-HEMT power amplifier and digital pre-distortion technique were developed. In this paper measurements and simulations of the system are presented.