Hideo Makishima

Design and performance of traveling-wave tubes using field emitter array cathodes

An X-band miniaturized traveling-wave tube (TWT) using a Spindt field emitter array (FEA) cathode was built. The FEA cathode has 542,000 molybdenum tips in an emission area 1.2 mm in diameter. It also has a trench current-limiter that shows low resistance in normal operation. A saturation output power of 28.2 W, a saturation power gain of 40 dB, and a beam transmission ratio of more than 99.3% have been achieved at a frequency of 11.5 GHz under 3% duty ratio.

Present and future of vacuum fluorescent display and field emission display

With the advancement of electronics, the role of a display as an interface between man and machine becomes increasingly important. Color liquid crystal displays (LCDs) used for personal computers as alternatives to color cathode ray tube (CRT) displays have helped enhance market awareness of flat-panel displays. Among the flat-panel displays of various types used in many ways, emissive displays hold a key position. This paper explains the vacuum fluorescent display (VFD) and the field emission display (FED) in terms of their current technical aspects and their future.

Remarkable improvements of microwave electron tubes through the development of the cathode materials

An X-band miniaturized traveling-wave tube (7WT) using Spindt-type field emitter array (FEA) cathode was built. The FEA cathode has 14,520 molybdenum tips in an emission area of 0.84 mm diameter and its cathode current density is 10.6 A/cm2. High RF per3cormances of 27.5 W output power and 19.5 dB gain have been achieved at a frequency of 10.5 GHz, a helix voltage of 3.35 kV and a cathode current of 58.6 mA. The beam efficiency is 14 % and the beam transmission ratio is 82 %.