Experimental study on oscillation characteristics of magnetron after turning off filament current

The objective of the present research is the application of a magnetron made for civilian use to a transmitter for a microwave power transmission system, including the solar power station/satellite (SPS) concept. Experiments show that, when a magnetron is made to oscillate with a DC stabilized power supply drive, the oscillation frequency spectrum becomes narrower, although the DC-RF conversion efficiency suffers somewhat if the filament current is turned off after oscillation than when the specified filament current flows in the thermal emission filament. The reasons for a narrower oscillation frequency spectrum are elimination of the disturbance of the anode current caused by the anode current–anode voltage relationship, one of the oscillation characteristics of the magnetron, and reduction of the thermal effect on electrons. By improvement of the frequency spectrum, it is now possible to configure a phased array system with high output, high efficiency, and low cost by means of a magnetron. Hence, a future application to SPS is expected. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(5): 1–9, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10116