Teruyuki Shimura

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This paper describes a 3.5-V operation HBT MMIC power amplifier module for use in GSM/EDGE dual-mode, 900/1800/1900-MHz triple band handset applications. With diode switches and a band select switch built on the MMIC, the module delivers a P/sub out/ of 35.5 dBm and a PAE of about 50% for GSM900, a 33.4-dBm P/sub out/ and a 45% PAE for GSM1800/1900. While(More)
Leukocytapheresis (LCAP) appears to remove or inactivate inflammatory cells and to reset immunological responses, resulting to cure responders of ulcerative colitis (UC). The changes of T cell subsets were investigated in UC patients treated with LCAP. Levels of T cell subsets in peripheral blood before and after LCAP were analysed by flow cytometric(More)
We present a high performance AlGaAs/GaAs power HBT with very low thermal resistance for digital cellular phones. Device structure with emitter air-bridge is utilized and device layout is optimized to reduce thermal resistance by three-dimensional thermal flow analysis, and in spite of a rather thick substrate (100 /spl mu/m), a low thermal resistance of(More)
This paper describes circuit design and measurement results of a pure HBT MMIC power amplifier module (PA) operating with a 2.5-V low reference (Vref) and 2.8-V low collector supply voltages (Vcc). While covering 824-925-MHz broadband CDMA operation at 2.8-V Vcc, the PA allows a 1.1-V low Vcc and 18-dBm Pout operation. This is realized by an on-chip step(More)
A multiband power amplifier using combination of CMOS and GaAs technologies (Combo MB PA) which supports quad WCDMA bands (Band V, VIII, II, I) is described. With four chips - two GaAs-HBT chips, a GaAs-HEMT chip, and a CMOS chip - mounted on a 5.5&#x00D7;5mm<sup>2</sup> laminate, the Combo MB PA comprises two amplifier chains and two SPDT HEMT band-select(More)
This paper describes circuit design and measurement results of a newly developed InGaP/GaAs HBT MMIC power amplifier module (PA) which can operate with 2.4-V low reference (V<sub>ref</sub>) and supply voltages of its on-chip bias circuits. To achieve the low-V<sub>ref</sub> operation, the following two new circuit design techniques are incorporated into the(More)
We have fabricated side-wall assisted 0.15 /spl mu/m T-shaped gate pseudomorphic HEMT DCFL circuits with InGaP donor layers and obtained 22.3 ps basic delay and 0.8 fJ power-delay products at a supply voltage Vdd of 0.6 V with the driver gate width of 2 /spl mu/m. A master-slave type divide-by-two frequency divider which consists of eight 2-input NAND gates(More)