Akio Wakejima, Kohji Matsunaga, Yasuhiro Okamoto, K. Ota, Yuji Ando, Tatsuo Nakayama, Hironobu Miyamoto,
... GaN-FET amplifiers are highly sought after for W-CDMA base stations. In order to obtain high output ... effects that obstruct digital predistortion (DPD) linearization in W-CDMA power amplifiers, we have newly developed the bias ... impedance at the base band of multi-carrier W-CDMA signals is reduced. As a result, the GaN-FET amplifier developed for W-CDMA base stations achieves a record 370-W W-CDMA peak output power, and a low DPD linearized ... of less than -50 dBc at the highest W-CDMA average output power of over 60 W, resulting ...
Tópico(s): Radio Frequency Integrated Circuit Design
2006 - Institute of Electrical and Electronics Engineers | IEEE MTT-S International Microwave Symposium digest
... service/wide-band code division multiple access (PCS/W-CDMA) dual-band monolithic microwave integrated circuit (MMIC) power ... the power amplifier effectively for both PCS and W-CDMA bands with no additional DC power consumption, and ... power of 28 (28) dBm for the PCS (W-CDMA) band while keeping the base bias voltage of the power amplifier as designed. A PCS and W-CDMA dual-band InGaP heterojunction bipolar transistor MMIC power ... under 3.4-V operation voltage for PCS (W-CDMA) applications.
Tópico(s): Microwave Engineering and Waveguides
2002 - Institute of Electrical and Electronics Engineers | IEEE Journal of Solid-State Circuits
Masaru Sekijima, Hiroshi Takeda, Katsuaki Yasunaga, Noriko Sakuma, Hideki Hirose, Toshio Nojima, Junji Miyakoshi,
... wave (CW) and Wideband Code Division Multiple Access (W-CDMA) RF fields at three field levels. During the ... or 800 mW/kg with both CW and W-CDMA RF fields for up to 96 h. Heat ... were observed between any test group exposed to W-CDMA or CW radiation and the sham-exposed negative ... level exposure to 2.1425 GHz CW and W-CDMA RF fields for up to 96 h did ...
Tópico(s): Ultrasound and Hyperthermia Applications
2010 - Oxford University Press | Journal of Radiation Research
Noriko Sakuma, Yoshiki Komatsubara, Hiroshi Takeda, Hideki Hirose, Masaru Sekijima, Takuya Nojima, Junji Miyakoshi,
... wave (CW) and Wideband Code Division Multiple Access (W-CDMA) modulated signal RF fields at 2.1425 GHz ... in cell culture. A172 cells were exposed to W-CDMA radiation at SARs of 80, 250, and 800 ... while IMR-90 cells were exposed to both W-CDMA and CW radiations at a SAR of 80 ... were observed between the test groups exposed to W-CDMA or CW radiation and the sham exposed negative ...
Tópico(s): Electromagnetic Fields and Biological Effects
2005 - Wiley | Bioelectromagnetics
... or combined multicarrier wireless code-division multiple-access (W-CDMA) signals and uses the phase-modulation method. Four ... 122.88 MHz) the symbol rate of the W-CDMA chip rate of 3.84 Mbit/s. The ... assignment and spacing of one or two independent W-CDMA channels. This paper outlines how the envelope and phase information of two combined W-CDMA channels may be pre-calculated in real time. ...
Tópico(s): Wireless Communication Networks Research
2005 - IEEE Microwave Theory and Techniques Society | IEEE Transactions on Microwave Theory and Techniques
... the performance of wideband code-division multiple-access (W-CDMA) systems using space-time-spreading- (STS-) based transmit ... diversity have the same order of importance. Since W-CDMA signals are subjected to frequency-selective fading, the ... is then proposed for improving the throughput of W-CDMA systems. Our numerical results demonstrate that this adaptive ... capable of significantly improving the effective throughput of W-CDMA systems. Specifically, the studied W-CDMA system's bitrate can be increased by a ...
Tópico(s): Cooperative Communication and Network Coding
2005 - Springer Nature | EURASIP Journal on Wireless Communications and Networking
Apostolos Papathanassiou, A.K. Salkintzis, P. Takis Mathiopoulos,
... uplink performance of two well-known transmission schemes, W-CDMA and OFDM, for mobile multimedia communications via LEO ... accordance with the corresponding UMTS system specifications. For W-CDMA, we propose a receiver structure that eliminates ISI ... of which is based upon the parameters of W-CDMA for UMTS. For both schemes appropriate transceiver structures ... user indicate that, although the BER performance of W-CDMA is slightly better than that of OFDM, the ...
Tópico(s): Advanced Wireless Communication Techniques
2001 - Institute of Electrical and Electronics Engineers | IEEE Personal Communications
Tomoyuki Shirai, Norio Imai, Jianqing Wang, Satoru Takahashi, Mayumi Kawabe, Kanako Wake, H. Kawai, Soichi Watanabe, Fumio Furukawa, Osamu Fujiwara,
... 2.14 GHz band code division multiple access (W‐CDMA) signals for 20 h a day, over three ... multigenerational whole body exposure to 2.14 GHz W‐CDMA signals for 20 h/day did not cause ...
Tópico(s): Energy Harvesting in Wireless Networks
2014 - Wiley | Bioelectromagnetics
Hiroyuki Nakamura, H. Nakanishi, Tetsuya Tsurunari, K. Matsunami, Y. Iwasaki,
A small-sized SAW duplexer for Wideband CDMA (W-CDMA) application at 2 GHz band has been developed. The W-CDMA application has a wide duplex gap between transmitting ( ... temperature coefficient of frequency (TCF) is needed. Our W-CDMA SAW duplexer was fabricated on a SiO 2 / ... spurious suppression technique has been applied to the W- CDMA SAW duplexer. The duplexer has excellent performance of ...
Tópico(s): Nonlinear Photonic Systems
2007 - Institute of Electrical and Electronics Engineers | Proceedings/Proceedings - IEEE Ultrasonics Symposium
Tomoyuki Shirai, Toshio Ichihara, Kanako Wake, Soichi Watanabe, Yukio Yamanaka, Mayumi Kawabe, Masao Taki, Osamu Fujiwara, Jianqing Wang, Satoru Takahashi, Seiko Tamano,
... 95‐GHz wide‐band code division multiple access (W‐CDMA) signal, which is a feature of the International ... in female rats exposed to 1.95‐GHz W‐CDMA signals showed tendencies to increase but without statistical ... of heads of rats to 1.95‐GHz W‐CDMA signals for IMT‐2000 for a 2‐year ...
Tópico(s): Noise Effects and Management
2007 - Wiley | Bioelectromagnetics
Hideki Hirose, Noriko Sakuma, N. Kaji, Koji Nakayama, Kohei Inoue, Masaru Sekijima, Takuya Nojima, Junji Miyakoshi,
... wave (CW) and Wideband Code Division Multiple Access (W‐CDMA) modulated signal RF fields at 2.1425 GHz ... hsps). Human glioblastoma A172 cells were exposed to W‐CDMA radiation at SARs of 80 and 800 mW/ ... 90 fibroblasts from fetal lungs were exposed to W‐CDMA at 80 and 800 mW/kg for 2 ... were observed between the test groups exposed to W‐CDMA or CW signal and the sham‐exposed negative ...
Tópico(s): Electromagnetic Fields and Biological Effects
2006 - Wiley | Bioelectromagnetics
Hideki Hirose, Noriko Sakuma, N. Kaji, Toshiaki Suhara, Masaru Sekijima, Takuya Nojima, Junji Miyakoshi,
... wave (CW) and wideband code division multiple access (W-CDMA) modulated signal RF fields at 2.1425 GHz ... stress. Human glioblastoma A172 cells were exposed to W-CDMA radiation at SARs of 80, 250, and 800 ... fibroblasts from fetal lungs were exposed to both W-CDMA and CW radiation at a SAR of 80 ...
Tópico(s): Wireless Body Area Networks
2006 - Wiley | Bioelectromagnetics
Donald F. Kimball, Ju Seon Jeong, Chin Hsia, Paul Draxler, Sandro Lanfranco, W. Nagy, K. J. Linthicum, L.E. Larson, P.M. Asbeck,
A high-efficiency wideband code-division multiple-access (W-CDMA) base-station amplifier is presented using high-performance ... is as high as 50.7% for a W-CDMA modulated signal with peak-to-average power ratio ... performance among reported base-station power amplifiers for W-CDMA. The measured error vector magnitude is as low ...
Tópico(s): Advanced DC-DC Converters
2006 - IEEE Microwave Theory and Techniques Society | IEEE Transactions on Microwave Theory and Techniques
Akio Wakejima, K. Matsunaga, Yasuhiro Okamoto, Yuji Ando, Tatsuo Nakayama, Hiroyuki Miyamoto,
... GaN-FETs exhibits a record 2.14 GHz W-CDMA output power. The amplifier, composed of paralleled 48 ... of 45 V under 2.14 GHz 3GPP W-CDMA signal input. The output power density (output power/ ...
Tópico(s): Radio Frequency Integrated Circuit Design
2005 - Institution of Engineering and Technology | Electronics Letters
Akio Wakejima, K. Matsunaga, Yasuhiro Okamoto, Yuji Ando, Tatsuo Nakayama, K. Kasahara, Hiroyuki Miyamoto,
... single-die GaN-FET was successfully developed for W-CDMA cellular base-station systems. The developed amplifier delivers ... of 48 V under 2.15 GHz 3GPP W-CDMA signal input. It is believed that the 280 ...
Tópico(s): Radio Frequency Integrated Circuit Design
2005 - Institution of Engineering and Technology | Electronics Letters
Villy B. Iversen, Eustachio Epifania,
Multi-band Wide — Band Code Division Multiple Access (W-CDMA) systems are considered to be among the best ... UMTS). To evaluate the performance of multi-band W-CDMA systems many parameters have to be taken into ... evaluate the state space of multi-band overlaid W-CDMA system, and we present a very powerful algorithm, ...
Tópico(s): Advanced Wireless Network Optimization
2003 - Springer Science+Business Media | IFIP advances in information and communication technology
W. Cooper, J.R. Zeidler, Stephen McLaughlin,
... performance of the wideband code-division multiple access (W-CDMA) randomized slotted-offset random access channel (RAC) with ... based RAC. Previously, it was shown that the W-CDMA RAC is fast, robust and simple to implement ( ... antennas. Compared to the randomized slotted-ALOHA designs, W-CDMA RAC performs as well in light fading conditions ...
Tópico(s): Cooperative Communication and Network Coding
2002 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Vehicular Technology
Seyyed Mohammad Mehdi Dehghan, R. Owen, Paul D. Jones, David Lister,
... of the air interface. This paper addresses FDD W-CDMA planning and capacity estimation issues. As well as ... on simulation methods and considerations. Finally an example W-CDMA network, based on realistic site locations in central ...
Tópico(s): Advanced MIMO Systems Optimization
2000 - | Electronics & Communications Engineering Journal
Fumiyuki Adachi, Mamoru Sawahashi, H. Suda,
... at third-generation mobile communications systems is reviewed. W-CDMA is designed to flexibly offer wideband services which ... as 2 Mb/s. The important concept of W-CDMA is the introduction of intercell asynchronous operation and ... from outdoors to indoors. Other technical features of W-CDMA include fast cell search under intercell asynchronous operation, ... of the data-channel-associated pilot channel allows W-CDMA to support interference cancellation and adaptive antenna array ...
Tópico(s): Advanced MIMO Systems Optimization
1998 - Institute of Electrical and Electronics Engineers | IEEE Communications Magazine
Erik Dahlman, B. Gudmundson, Mats Nilsson, A. Skold,
... between ETSI/Europe and ARIB/Japan based on W-CDMA, a GSM core network, and a common frequency ... global IMT-2000 standard feasible. UTRA based on W-CDMA fully supports the UMTS/IMT-2000 requirements (e. ... rate services, and an efficient packet mode. Key W-CDMA features also include improved basic capacity/coverage performance ... companies, and full system tests are ongoing. Consequently, W-CDMA technology can now be regarded as a mature ...
Tópico(s): Power Line Communications and Noise
1998 - Institute of Electrical and Electronics Engineers | IEEE Communications Magazine
Setsu Nakatani‐Enomoto, Miho Okutsu, Satoshi Suzuki, Ryota Suganuma, Stefan Jun Groiss, Suguru Kadowaki, Hiroyuki Enomoto, Keiya Fujimori, Yoshikazu Ugawa,
... to 1950 MHz Wideband Code Division Multiple Access (W-CDMA)-like EMW with specific absorption rates of either ... variables, or 8-OHdG levels. We conclude that W-CDMA-like exposure for 1 h under temperature-controlled ...
Tópico(s): Reproductive Health and Technologies
2016 - Wiley | Bioelectromagnetics
Setsu Nakatani‐Enomoto, Toshiaki Furubayashi, Akira Ushiyama, Stefan Jun Groiss, Kazumune Ueshima, Shigeru Sokejima, Ally Y. Simba, Kanako Wake, Soichi Watanabe, Masami Nishikawa, Kaori Miyawaki, Masao Taki, Yoshikazu Ugawa,
... phones using a Wideband Code Division Multiple Access (W‐CDMA)‐like system on human sleep. Subjects were 19 ... wave EMF exposure for 3 h from a W‐CDMA‐like system has no detectable effects on human ...
Tópico(s): Sleep and Wakefulness Research
2013 - Wiley | Bioelectromagnetics
Yoko Mizuno, Yoshiya Moriguchi, Takashi Hikage, Yasuo Terao, Takashi Ohnishi, Toshio Nojima, Yoshikazu Ugawa,
... emitted from the Wideband Code Division Multiple Access (W‐CDMA) cellular system versus sham control exposure on rCBF ...
Tópico(s): Functional Brain Connectivity Studies
2009 - Wiley | Bioelectromagnetics
Hideki Hirose, Atsushi Sasaki, Nana Ishii, Masaru Sekijima, Takahiro Iyama, Toshio Nojima, Yoshikazu Ugawa,
... a 1950 MHz Wideband Code Division Multiple Access (W-CDMA) RF field, at specific absorption rates (SARs) of ... microglial cells, was similar between cells exposed to W-CDMA radiation and sham-exposed controls. No statistically significant ... were observed between the test groups exposed to W-CDMA signal and the sham-exposed negative controls. These ...
Tópico(s): Noise Effects and Management
2009 - Wiley | Bioelectromagnetics
Hiroaki Deguchi, Norihiko Ui, Kaname Ebihara, Kazutaka Inoue, Norihiro Yoshimura, Hidenori Takahashi,
... 45.2 dBm (33 W) with 4-carrier W-CDMA signal at 2.6 GHz using commercially available ... 6 GHz band base stations (BTS), for example, W-CDMA, LTE and WiMAX, and small-sized circuit structure ...
Tópico(s): GaN-based semiconductor devices and materials
2009 - Institute of Electrical and Electronics Engineers | IEEE MTT-S International Microwave Symposium digest
Chi-Tsan Chen, Chien-Jung Li, Tzyy‐Sheng Horng, Je-Kuan Jau, Jian-Yu Li,
... applied to a dual-mode RF transmitter for W-CDMA/WiMAX systems. At first, a Class-E PA ... adjacent channel power rejection for 1.95 GHz W-CDMA and 2.6 GHz WiMAX applications.
Tópico(s): Radio Frequency Integrated Circuit Design
2009 - Institute of Electrical and Electronics Engineers | IEEE MTT-S International Microwave Symposium digest
Takashi Yamamoto, Takaya Kitahara, Shigeru Hiura,
... amplifier for a wideband code-division multiple-access (W-CDMA) signal that has a peak-to-average power ... drain efficiency of a Doherty amplifier for a W-CDMA signal to the best of the authors' knowledge.
Tópico(s): GaN-based semiconductor devices and materials
2007 - Institute of Electrical and Electronics Engineers | IEEE MTT-S International Microwave Symposium digest
I. Takenaka, Kohji Ishikura, H. Takahashi, Kouichi Hasegawa, Takashi UEDA, Toshimichi Kurihara, Kazunori Asano, Naotaka Iwata,
... the two-carrier wideband code-division multiple-access (W-CDMA) signals of 2.135 and 2.145 GHz. ... among the simple high-power FET amplifiers for W-CDMA base stations. In addition, we proposed the evaluation ...
Tópico(s): Full-Duplex Wireless Communications
2006 - IEEE Microwave Theory and Techniques Society | IEEE Transactions on Microwave Theory and Techniques
Paul Draxler, Sandro Lanfranco, Donald F. Kimball, Chin Hsia, Jinseong Jeong, J. De Sluis, P.M. Asbeck,
A high performance W-CDMA base station power amplifier is presented, which uses an envelope tracking bias system along with an advanced 0.4mum ... the highest reported for a single stage LDMOS W-CDMA base station amplifier
Tópico(s): Advanced DC-DC Converters
2006 - Institute of Electrical and Electronics Engineers | IEEE MTT-S International Microwave Symposium digest
I. Takenaka, K. Ishikura, H. Takahashi, Kouichi Hasegawa, Tetsuzo Ueda, Terumasa Kurihara, K. Asano, N. Iwata,
... 6dB back-off level under the two-carrier W-CDMA signals of 2.135GHz and 2.145GHz. To ... among the simple high power FET amplifiers for W-CDMA base stations. Moreover, we proposed the evaluation techniques ...
Tópico(s): Wireless Power Transfer Systems
2006 - Institute of Electrical and Electronics Engineers | IEEE MTT-S International Microwave Symposium digest