H
Hiroshi Okazaki
Researcher at NTT DoCoMo
Publications - 120
Citations - 987
Hiroshi Okazaki is an academic researcher from NTT DoCoMo. The author has contributed to research in topics: Amplifier & Antenna (radio). The author has an hindex of 17, co-authored 115 publications receiving 946 citations. Previous affiliations of Hiroshi Okazaki include Nippon Telegraph and Telephone.
Papers
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Patent
Quadrature hybrid circuit
TL;DR: In this paper, the first and second two-port circuits are configured so that under the condition that the I/O ports P 1 to P 4 are matched, a high-frequency signal fed via the IO port P 1 is divided between the IO ports P 2 and P 3 and the divided two signals are output 90° out of phase with each other.
Journal ArticleDOI
Novel 900 MHz/1.9 GHz dual-mode power amplifier employing MEMS switches for optimum matching
TL;DR: In this article, a dual-band GaAs FET amplifier is designed for the 0.9 GHz and 1.9-GHz bands, and the experimental results exhibit the small signal gain of greater than 16 dB and the saturated output power of 31 dBm.
Patent
Leakage power reduction apparatus
TL;DR: In this paper, a circulator extracts a transmission signal sent from a transmitter to antenna via the circulator and a duplexer, reflected by an antenna, and returned via the duplexe to the transmitter side.
Proceedings ArticleDOI
A 900/1500/2000-MHz triple-band reconfigurable power amplifier employing RF-MEMS switches
TL;DR: In this paper, a triple-band reconfigurable power amplifier (PA), which comprises the band-switchable matching networks with RF-MEMS switches, is presented and switch requirements for multi-band operation are discussed.
Patent
Matching circuit and multi-band amplifier
TL;DR: In this article, a matching circuit includes a demultiplexer for demuliplexing a signal outputted from an amplification device into signals of respective frequency bands, and at least two matching blocks which are connected to the demulterer, respectively fed with the signals of the corresponding frequency bands of the inputted signals.