JRC REVIEW No.60 Technical Reports

- JRC・Special Issues on Technical Evolution -

JRC has developed many kinds of surface acoustic wave (SAW) devices for about thirty years, such as IF filters for wireless communications, RF filters for portable devices, RF filters for automotive applications and SAW oscillators for optical communications. For IF filters for wireless communications, some design techniques for slanted finger SAW filters have been developed in order to achieve desired amplitude and phase responses in the pass band. For RF filters for portable devices, flip-chip assembly techniques for SAW devices have been developed in order to reduce the size. The flipchip SAW filters have achieved a size reduction of portable phones. Furthermore, flip-chip SAW filters for automotives have been released. For the module applications, GHz-band surface transverse wave (STW) based oscillators for optical communications have been developed. Recently, SAW biosensors and SAW liquid-phase sensors have been developing for future new applications, such as medical, environmental and foods.

Hisakazu Taguma
Hiromi Yatsuda

- JRC・Special Issues on Technical Evolution -

JRC has applied the radar technology cultivated for years to marine radar, vessel traffic management system, meteorological radar, airport surveillance radar, reinforced concrete radar and special radar, etc. and has offered the equipment widely along the customer needs : support for safety navigation of a ship or an airplane, disaster prevention, and nondestructive search, etc. Here, it first introduces the evolution of the radar development of JRC, and, next, the trend of the radar technology is described.

Hiroki Sugawara
Hideki Hashimoto
Naoya Hiraki
Takahiro Itagaki
Noboru Kawahara
Takashi Shimada
Masaru Kawaguchi

- JRC・Special Issues on Technical Evolution -

JRC's linear power amplifier for mobile transceivers evolved to have SAFF (Self Adjusting Feed Forward) , and has further evolved to have high speed FF (Feed Forward) , and DPD (Digital Pre-Distortion) . This amplifier also has come to have low electricity consumption, small size, and low price. In addition, these amplifiers have become self adjusting and have achieved dramatically higher productivity. On the other hand, with the emergence of a new generation of power devices, the structure of amplifiers has evolved from parallel configurations to the Doherty type, and their efficiency has continued to improve. We here introduce these evolutions in technology, and lastly describe current efforts to make further improvements.

Kinji Kato
Tamaki Honda
Keijiro Ito
Eiki Takahashi

- JRC・Special Issues on Technical Evolution -

The beginnings of JRC's work in microwave communications, used today in many areas as means of electric communication, for public use and in broadcasting, date far back to the years just after the end of World War II in 1945. Since then, the reliability of microwave multiple channel communication became widely recognized and as a result, it rapidly became widely adopted as means of communication in government agencies and a variety of other areas. Recently, microwave radios equipped with IP interfaces for broadband communication applications have entered the market. This report introduces the progress of JRC's microwave communications technology over these 60years.

Masahiko Tanizawa
Gaku Takamizawa
Masatoshi Nagayasu
Yuichi Torai
Takahiro Yamamoto

- JRC・Special Issues on Technical Evolution -

A GPS receiver is well known as a positioning sensor of a car navigation system and a mobile phone. GPS enables accurate positioning continuously 24 hours under any weather conditions all over the world. Japan Radio Co., Ltd. (JRC) has taken interest in the prospect of GPS since the emergence of GPS. As the result, JRC has been able to develop the world's first GPS receivers for navigation systems installed into the automobile, and has built the top market share of the automotive usage's GPS receivers. In addition, GPS receiver and GPS compass for the maritime usage have also received high recognitions. Since over thirty five years have passed after the beginning of GPS development, Global Navigation Satellite System (GNSS) becomes more important than before; U.S. is modernizing the GPS, Russia is modernizing the GLONASS, EU is proceeding development of the Galileo, and Japan is proceeding development of the Quasi-Zenith Satellite System (QZSS) . On this paper, we introduce evolution of JRC's GPS receivers for automotive usage, GPS receivers for maritime usage, and GPS compass, and introduce to the future trends of GNSS.

Yoshiharu Ogasa
Hiroya Suzuki
Toshihiro Kawazoe

- JRC・Special Issues on Technical Evolution -

The introduction of FM in the police radio communications system in 1950 led to the start of land mobile communications with FM radio. Just at the start of FM radio communications, JRC developed a radio device using vacuum tubes. Since then, with developments in devices and circuits, the overall sizes have become progressively smaller. At the same time, more efficient use of frequencies have made it possible for communications through narrower bands to be developed. Recently, digital systems have been introduced. This report explains technological evolution in JRC commercial use wireless devices during these years, using representative product models as examples.

Satoshi Tsuchiya
Takuya Noda
Shuichi Takahashi

- JRC・Special Issues on Technical Evolution -

Based on the Disaster Countermeasure Basic Act of Japan set forts in the Basic Law for Disaster Control Measures. The Municipal Disaster Management Radio Communication System have been constructed in national, prefectural, and municipal level as means to gather and deliver disaster information at times of emergency disasters. These system consist of VHF・UHF radio communication link, microwave communication link and satellite communication link, and can be categorized into fixed systems, simultaneouscommunication systems, and mobile systems.

JRC as a various radio communication equipment provider, has been developing and providing such as Disaster Management Radio Communication System to the central and/or local government early stage of establishment since 1975.

In2004,transformation of voice communication facilities from analog systems to digital systems which can handle multimedia was began. Since then, planning has continued for the integration of wireless communication networks with IP communication networks using optical fibers.

This report describers JRC's efforts in constructing the above systems, and overall evolution in disaster administration wireless system.

Satoru Ishigaki

- JRC・Special Issues on Technical Evolution -

Water Flood and River information System are the disaster prevention systems that The Ministry of Land Infrastructure and Transport and the municipality maintain. It is a system that collects the data of the rainfall, the water level, the dam data, and the water quality, etc. to defend people's lives and the properties from high water by the flood or the typhoon etc, and offers information to the river authority The computer information device equipment that the function was consistent became ef ficient, reduction in costs, the labor saving, and the miniaturization each year and depends on social circumstances.

At same time, According to social demand, and that turned Water Flood and River information System construction and system value-added strategy for change. We plainly explain the evolution of the method for construction of "Water Flood and River information system" that is a typical system of JRC.

Takayuki Goto

- JRC・Special Issues on Technical Evolution -

To meet the demands of the market, the technology used for Inmarsat has been evolving ever since it started to provide stable mobile marine communications by replacing communication in the medium and high frequency band with microwave communication using artificial satellites. In response to changing demands, services have been added to the originally provided telephone, fax, and telex which make communication by e-mail and other data transmission means simple.

This report deals with the development and start of manufacture of Inmarsat communication equipment by JRC over the course of more than 30 years. The evolution in each generation of these products, from the Inmarsat A System to the present Inmarsat FleetBroadband system, are introduced.

Shigeru Senoh
Nobuyuki Ito

- JRC・Special Issues on Technical Evolution -

Shipbone MF/HF radio equipment is required to install to the SOLAS convention ships that engage international voyage, and is even now the only shipbone radio equipment capable of long distance terrestrial communication. For a long period since the early twentieth century, the radiotelegraph communication with Morse code and the later SSB radiotelephone communication were the mainstay of the long distance communication for the ships. However, the distress signal of Morse code SOS had repealed because the Inmarsat communication system have spread and GMDSS have started. Instead the distress signal SOS, the function of distress alart by DSC (Digital Selective Call) have installed in MF/HF radio equipment as GMDSS. This report introduces technical evolution of JRC MF/HF Radio Equipment since approximately the start of GMDSS.

Eiichi Kobayashi
Shoichi Kuromori

- JRC・Special Issues on Technical Evolution -

JRC's Production Department, which has taken on the manufacture of communication devices that are the mainstay of JRC, has changed as the trends of the times have changed. We have made innovations in our manufacturing methods as well as the structure of our products. There is continuity in our machine processing technology from the time of JRC's founding until the present, and moreover we have achieved great improvements in our processing facilities.

Specifically, technology for electronic part installation has evolved since the introduction of automatic devices in the 1980's, and has undergone other great changes in recent years.

This report describes the evolution in manufacturing that have been brought about by new machine processing technology and electronic parts installation technology, from the viewpoint of processing facilities and automatic machines.

Yasuhiro Amano
Kenji Nambu
Takeshi Morino
Masaki Yoda