The technical development of crystals and oscillators in China and their market situation

In recent years the manufacture of and demand for crystals and oscillators in China have been increasing quickly because of the development of industries, communications, science, transportation, and electronic techniques. This paper introduces the manufacture, research, and characteristics of the technical development of crystals and oscillators in the last ten years in China. To meet the demand from industry, science, and other markets, the number of companies that produce and research crystals and oscillators has increased from several to more than 300 in the last 20 years. Manufacturing technology and equipment have also improved. For marketing and technical reasons, more than 75% of the companies manufacture mainly 49 /spl mu/, 49 /spl mu/s, and /spl mu/m crystals. Now more and more companies plan to build production lines to make cold-weld crystals and other precision crystals, and at least two companies have already built their production lines. Most of the precision crystals are AT-cut but some are SC-cut. Integrated TCXOs and DTCXOs have been made by different companies, and the frequency-temperature stability of them is from /spl plusmn/2 ppm to /spl plusmn/0.5 ppm in a wide temperature range. Specifications of some OCXOs are almost the same as those of foreign OCXOs. The main design techniques in China are experimental. However, in recent years, specially designed software has been developed for oscillator design, and advanced instrumentation and equipment are used. The market situation for crystals and oscillators has increased.