Tatsuya Hagiwara

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Recent studies on traffic measurement analysis in the various networks have shown that packet traffic exhibits Long Range Dependent properties called Self-Similarity. Some papers reported that Self-Similarity degrades the network performance, such as buffer overflow. Thus, we need new network control considering Self-Similar properties. Network control(More)
A 15GHz 4-channel transmit/receive RF core-chip is presented for high SHF wide-band massive MIMO in 5G. Both phase shifters (PS) and variable gain amplifiers (VGA) with high resolution and high accuracy are integrated in each TX and RX path of the chip. A calibration technique to compensate the error of 6bit PS caused by I/Q mismatch in the poly phase(More)
In this paper, an L-band transmitter and receiver MMIC, which is known as a core chip for phased array communication and radar applications is presented. The MMIC is fabricated in 0.18 μm SiGe-BiCMOS process, comprises an RX amplifier, a 5-bit active phase shifter, SPDT switches, and a TX amplifier. The RX amplifier realized low noise and high(More)
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