JRC REVIEW No.55 Technical Reports

- Special Issues : Device / Module -

High efficiency Digital Pre- Distortion (DPD) power amplifiers are strongly demanded for compact and low-cost 3.9G base station transmitters. JRC has recently developed the high-efficiency DPD power amplifier which consists of the multistage amplifier using internally class-E matched GaN packaged device and the proprietary DPD reducing memory effect distortion. The driver amplifier using GaN transistor also contributes both the high efficiency and the distortion reduction of the multi-stage amplifier because of its distortion characteristics nearly opposite to the final amplifier. A peak limiter is applied to reduce Peak to Average Power Ratio (PAPR) with minimum degradation of Error Vector Magnitude (EVM) . We have shown that the multi-stage power amplifier achieves 42.7% overall efficiency at 28.2W average output power (7.7dB back-off) , and the DPD cancels distortion more than 30dB.

Hirohisa Hirayama
Toru Hada
Koji Fukino
Koki Shibata
Takaaki Ishikawa
Takayoshi Sasaki
Yoshio Miyazawa
Takuya Funayama
Takashi Watanabe

- Special Issues : Device / Module -

JRC has developed burst mode equalizer for digital wireless communication systems of business applications. The purpose of this equalizer is to secure communication quality under frequency selective fading channels caused in mountain areas or high-rise buildings areas. Adaptive equalizer combats intersymbol interference (ISI) on the received signal which degrades the performance significantly. JRC has studied the adaptive equalizer adopted for burst frame signals, called burst mode equalizer. The burst mode equalizer has been applied to conventional digital burst modem. This paper describes problems and solutions to develop the burst mode equalizer.

Hidefumi Murata
Kazutoshi Tsuda
Koki Shibata
Masatoshi Nagayasu
Hiroyuki Inokuchi
Shuji Hirosawa
Makoto Yasui

- Special Issues : Device / Module -

Recently, planar antennas such as a slotted waveguide array or a patch array have been used in Wireless Access Equipment since all circuits are easily integrated on the back of the antenna. The Wireless Access Equipment that adopts a planar antenna can be easily installed at the base station and it is also has good aesthetics. However, for patch arrays with over 1000 elements, the dielectric material has huge loss due to the long transmission line. Furthermore, a wind resistance over 90m/s is required for the half wavelength radome. JRC has developed a 22 GHz band planar antenna for Wireless Access Equipment. It consists of 1024 patch elements and has high efficiency due to the use of striplines. In addition, we have selected fiber reinforced plastic for the half wavelength radome, and it has been confirmed by simulation that the radome possesses a wind resistance greater than 90m/s.

Goro Yoshida
Yuzo Shibuya
Yohei Miura
Naohisa Goto
Shunji Takeuchi
Toshiyuki Inoue
Keiji Adachi
Sadami Himori

- Special Issues : Device / Module -

Single-layer slotted waveguide arrays are developed for microwave and millimeter wave application. An alternating phase fed array, which is one type, consists of a slotted plate and a waveguide base, is low-profile antenna and is easy to fabricate. The center-feed type of the antenna has two important design advantages: the array bandwidth is doubled and the direction of the boresight beam is frequency-independent. JRC has developed this antenna for wireless communication systems. This project introduces to analysis whole antenna model by electromangetic method which can confirm final trial manufacture. And this paper reports two inventions to improve side-lobe level and antenna aperture efficiency.

Goro Yoshida
Yuzo Shibuya
Yasuhiro Tsunemitsu
Naohisa Goto
Makoto Ando^*
Jiro Hirokawa^*
*Tokyo Institute of Technology

- Special Issues : System / Solution -

JRC has developed a solid-state power amplifier (SSPA) for X-band marine radar systems employing new gallium nitride high electron mobility transistors (GaN HEMTs) of over 120W. The developed SSPA achieved the peak output power exceeding 400W, in combination of four GaN HEMTs, under pulse operation at 9.4GHz. The SSPA is small with the dimensions of 187(W)×140(H)×48(D)mm, which enables reduction of the size of marine radar units. This result is part of R&D for improving the frequency utilization efficiency, which is a contract research from the Ministry of Internal Affairs and Communications.

Masanori Sudoh
Hiroki Sugawara
Masaya Sawayanagi
Junji Yamagata

- Special Issues : System / Solution -

Recently, it starts the development of Galileo that is an original satellite navigation system also in Europe though GPS of the United States is being widely used in the market such as the car navigations now. Galileo is a system to which operation by both government and the private organization in Europe is required though GPS is operated by the United States Government budget. Therefore, because more public and integrity increase compared with the current state shown only in GPS that the national interest of the United States is prioritized, the expectation of Galileo for completion is great. In this paper, JRC introduce Galileo/GPS receiving method that develops newly in addition to the GPS receiver.

Koichi Washizu
Masahiro Genda
Yun Qiao

- Special Issues : System / Solution -

The assignment of 10 MHz in the UHF band (715 to 725 MHz) for ITS inter-vehicle communication systems was decided in the Japan Telecommunications Council report on June 27, 2007. The purpose of this bandwidth assignment is to avoid head-on collisions in intersections and other areas with reduced visibility by allowing vehicles to inform each other of their locations through 720MHz radio wave transmissions. The bandwidth assignment will take effect on July 25, 2012. CSMA is the dominant protocol in inter-vehicle communication systems, but serious degradation in performance caused by the hidden node problem is a concern. This study proposes and evaluates a new media access protocol designed for dealing with this problem. The study computes the range of occurrence of hidden nodes in a head-on collision scenario. The study indicates the amount of influence that those nodes have while evaluating the simulated packet arrival rates of both the proposed protocol and the conventional protocol. The study concludes that the proposed protocol is superior.

Shigeyuki Asami
Kunimitsu Arai

- Special Issues : New Field -

The aim of our study is to develop wearable environmental gas sensing system using surface transverse wave (STW) sensor coated with plasma-polymerized (PP) films as gas molecular recognition part. In this study, PP films coated with STW device were prepared from model monomers under atmospheric pressure: allylamine and styrene. The gas sorption property of STW gas sensor devices coated with PP allylamine and styrene was evaluated for water vapor.

Hiromi Yatsuda
Toshimasa Mori
Makoto Nara

- Special Issues : New Field -

Shear horizontal surface acoustic wave (SH-SAW) sensors are highly sensitive in detecting the properties of liquid, which are as relative permittivity, conductivity, viscosity and mass density. In this paper, experimental results of 50 MHz twochannel SH-SAW sensors on 36Y-X LiTaO3 are presented. The measured relative permittivity and conductivity for the liquid with different concentrations of Dioxane are shown using a relative permittivity-conductivity chart. Since SH-SAW which is propagating on the unmetallized propagation area in the liquid with a low permittivity attenuated due to a lack of energy concentration of the surface, the obtained permittivity and conductivity were slightly different from the exact values. In order to improve this drawback, a compensation method is presented.

Hiromi Yatsuda
Takashi Kogai

- Special Issues : New Field -

In order to realize miniature biosensors for real-time, rapid and direct detection, a liquid-phase sensor using shear horizontal surface acoustic waves (SH-SAWs) on quartz is presented. On the sensor chip, there is an SH-SAW delay line that is composed of a transmitting interdigital transducer (IDT) , receiving IDT and a biochemical reaction area in between them. The biochemical reaction area is surrounded with epoxy wall to protect the IDTs from liquid. In order to evaluate the performance of an SH-SAW delay-line sensor, C-reactive protein antibodies with different concentrations are provided to the biochemical reaction area. The phase changes in the S21 response of a 250 MHz SH-SAW delay-line at a fixed frequency are measured on real-time and it is confirmed that different phase changes are obtained for different antibody concentrations. Furthermore, a concept of one-chip biosensor system that is composed of SH-SAW delay lines for sensing and additional IDTs to excite Rayleigh type SAWs for SAW streaming on a chip. In this paper, one-chip quartz-based liquidphase SH-SAW delay-line sensor systems with pumping and agitating functions using Rayleigh type SAWs are demonstrated.

Hiromi Yatsuda
Takashi Kogai

- Technical Papers -

The preparations for Japan's total shift to digital terrestrial television broadcasting on July 24, 2011, are proceeding at a fast pace. By last year, preparations for major, high-power broadcast relay stations were completed, thus firmly securing a large number of households with access to digital terrestrial broadcasts. From this year onward, the main focus will be on preparing low-power broadcast relay stations in order to provide broadcasting throughout Japan. The facilities of these lowpower broadcast relay stations are small in scale, but a vast number of them require preparations for terrestrial broadcasts, so the need for small, low-cost solutions is now greater than ever.

To meet this need, JRC has developed the JBS-203 Series Transposer for Terrestrial Digital TV Broadcasting which is allin-one relay broadcaster for low power. This document introduces the JBS-203.

Kenichi Kohno
Satoru Akahori
Kazuhiro Hashimoto
Yasuhisa Onoda
Kazuyoshi Suzuki
Ryo Nomura