Masakazu Muraguchi

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We describe a new direct digital synthesizer (DDS) in which output tuning resolution is flexibly controlled. The new DDS has an extended phase accumulator (EPA) controlled by two frequency control words; one determines the wave number within a single EPA operation cycle, and the other determines the length of the cycle. The EPA allows the DDS to provide(More)
A miniaturized MMIC analog phase shifter using two quarter-wave-length transmission lines is described. The number of transmission lines it uses is half that of a conventional analog phase shifter, which uses a 3-dB 90/spl deg/ branch-line hybrid. The chip size of the experimental GaAs MESFET MMIC analog phase shifter is less than 0.71 mm/sup 2/, and a(More)
Previous studies suggested that the hydrophobic protein chargerin II, which is encoded in the A6L of mitochondrial DNA, may have a key role in the energy transduction by mitochondrial H(+)-ATP synthase because an antibody against chargerin II inhibited ATP synthesis and ATP-Pi exchange, in an energy-dependent fashion. In the present work, the contents of(More)
We have studied numerically the time-dependent photon-assisted tunneling (TD-PAT) process for electrons confined in quantum dots (QDs) by employing the finite difference method under the scheme of the TD-density functional theory (DFT). We have found the quasi-dark state (quasi-DS), where the injected electron remains in the QD. By varying the barrier(More)
19 GHz-band GaAs MESFET switch ICs have been demonstrated, intended for use in high-speed wireless LAN systems. The FET channel is fabricated on a SiO/sub 2/ insulator in order to reduce parasitic FET drain-source capacitance (Cds) which acts as off-state capacitance (Coff) in switches. The LOXI (Layered-Oxide-Isolation)-MESFET has enough DC and RF(More)