Hiroshi Okazaki

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Reconfigurable radio frequency (RF) circuits will be a predominant solution for future global and compact mobile terminals, which supports 2G, 3G, and LTE cellular systems in various frequency bands. A single-path configuration and use of single-band devices with distributed reconfigurable matching networks have the potential to achieve the optimum RF(More)
A single-path configuration and use of single-band devices with distributed reconfigurable matching networks have the potential to achieve the optimum RF front-end for future multi-band mobile terminals. Considering the difficulties in configuring a practical tunable filter as a top filter, collaboration between the filter and low-noise amplifier (LNA) is a(More)
This paper presents a novel concurrent multi-band power amplifier. A newly proposed multi-section impedance transformer provides impedance matching in individual bands at the same time. Each section is synthesized to match the corresponding operation band and to prevent impedance deviation in other matched bands by employing a branched stub. A 1W-class(More)
This paper presents a novel design scheme for a bandswitchable multi-band power amplifier (BS-MPA). A key point of the design scheme is configuring multi-section reconfigurable matching networks (MR-MNs) optimally in terms of low loss matching in multiple frequency bands from 0.7 to 2.5 GHz. The MR-MN consists of several matching sections, each of which has(More)
This paper presents a compact wideband rat-race hybrid composed of composite right/left-handed transmission lines (CRLH-TLs). Using CRLH-TLs with phase delays of -90 degrees and a right-handed transmission line (RH-TL) with 90 degrees at a design frequency, a relative bandwidth of about 36% can be obtained at the design frequency of 4 GHz. Furthermore, size(More)
This paper proposes an integrated module configuration including a slot antenna and a substrate integrated waveguide (SIW) filter for a vehicular transceiver. It is very important that the vehicular transceiver provides lower profile and lighter weight because of installing for an automobile roof. The proposed configuration only employs one print board(More)