NDK crystal devices are not only used in smartphones in the communications field. We have been a key player in the communications field since the analog era and have been a core contributor to creating the network of base stations that is so vital to our current social infrastructure. In 5G systems, especially for the controller base stations called the central unit (CU) and distributed unit (DU) base stations, extremely stable 25mm x 22mm oven-controlled crystal oscillators (OCXOs) are used.
5G Network System
CUs and DUs only use a few OCXO units each, but the specifications for the highly stable OCXOs needed as reference clocks require raw crystal with very high-purity and high-quality properties. Moreover, the specification requirements for 5G CU/DU stations are becoming increasingly demanding, making it necessary to further enhance the performance of current components.
NDK provides integrated large-volume production of highly stable OCXO using our own high-quality raw crystals and supplies consistent-quality, high-performance products to base station developers in Japan and overseas. NDK is the sole crystal device manufacturer with the elemental technology for fully integrated production of oscillators from raw crystals.
An OCXO unit is a fusion of a high-precision crystal unit and advanced circuit technology. One of NDK's current strengths is that it is the sole Japanese company actively engaged in the OCXO business for base stations. In fact, NDK is one of only five makers of OCXOs for base stations worldwide, and NDK has been constantly acquiring market shares.
[NH25M22TE 25mm x 22mm OCXO]
The 5G systems use high-frequency radio waves called Sub6GHz and millimeter waves. Although the communication speed is faster than 4G radio waves, 5G radio waves have strong directivity but short range, which means that it requires a high number of wireless base stations. For this reason, 5G is also expected to lead to an increase in the number of small radio unit (RU) wireless base stations.
Projected number of base stations
We expect RUs to be installed in urban centers with a lot of communication traffic such as on building walls and rooftops and on top of poles, which were previously unexpected.
Since RUs will not be installed inside air-conditioned buildings, the OCXOs for RU must not only be compact, they must also maintain stable performance in extremely harsh conditions including vibrations from external sources and weather conditions like torrential rains and wide temperatures that ranges from direct summer sunlight to winter snowfall.
NDK offers the world’s smallest-class 7mm x 5mm OCXO oscillators. This product is a culmination of our painstaking efforts to bring together the small circuit integration and ultra high-density mounting technologies we developed for our TCXO and VCXO oscillators.
[World's smallest-class 7mm x 5mm OCXO NH7050SA capable of handling high temperatures (+95°C) for 5G base stations]
NDK is aggressively working to put the business for 5G base stations on track, but we are also preparing for future business and to make further expansion.
NDK was openly recruited by The Ministry of Economy, Trade and Industry, jointly with the National Institute for Information and Communications Technology, University of Tokyo, and Tohoku University to study "Post 5G Information and Communications Systems Fundamental Reinforcement R&D Project/Leading Research (consigned)". NDK has started to study time synchronization technology with the title of “Innovative Communication Devices and Applications Development based on Extreme Time Synchronization”, which is expected to become increasingly important in future technologies.
Since its foundation, NDK has advanced the development of the electronics industry from the inside as a manufacturer specializing in crystal devices that control, select, and detect frequencies. From 5G to 6G. In addition, to support continuous development of digital society, we will contribute to make our world more safe, secure, and comfortable by continuously providing high-precision, highly reliable products.
Ministry of Economy, Trade and Industry
Companies selected in the Project for Research and Development of Enhanced Infrastructures for Post 5G Information Communication Systems / Advanced Research (Commissioned)