Novel hybrid 12-pulse boost-type rectifier with controlled output voltage

Novel hybrid 12-pulse line interphase transformer (LIT) rectifier systems with integrated single-switch or two-switch boost-type output stage that ensure a constant output voltage independent of mains and load conditions are proposed for supplying actuators of future more electric aircraft. The principle of operation, the dimensioning, and the system control are discussed. The theoretical considerations are experimentally confirmed for a 10 kW laboratory prototype. Finally, the single-and the two-switch system are comparatively evaluated concerning the level of input current ripple, power factor, and overall efficiency.     

MMW scanning antenna

Cost reduction is one of the most important considerations in millimeter-wave (MMW) radar development. Hardware, especially the phase-shifters, for electronic beam scanning in the MMW band presents very complex fabrication challenges that dramatically raise the device cost. A typical mechanically-scanning antenna contains one or more hinged parts (lenses, mirrors or feeds). In operation they experience strong mechanical accelerations and other forces that sharply limit the scanning speed. We propose a solution to this problem, using a leaky-wave periodically loaded antenna design and a new architecture. This paper presents the basic design, and discusses related issues