Koji Imamura

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This paper describes an ultra-low power (ULP) single chip transceiver for wireless body area network (WBAN) applications. It supports on-off keying (OOK) modulation, and it operates in the 2.36-2.4 GHz medical BAN and 2.4-2.485 GHz ISM bands. It is implemented in 90 nm CMOS technology. The direct modulated transmitter transmits OOK signal with 0 dBm peak(More)
This paper presents an ultra-low-power 2-step wake-up receiver for the IEEE 802.15.4g. The receiver is composed of an ultra-low-power energy-detection receiver (EDRX) and an address-detection FSK receiver (ADRX). The ADRX is activated only when the EDRX detects a wakeup packet which minimizes power consumption. Fabricated in a 65 nm CMOS process, the(More)
This paper presents an ultra-low-power (ULP) 2.3/2.4GHz multi-standard transmitter (TX) for wireless sensor networks and wireless body area networks. Several 2.3/2.4GHz wireless standards have been proposed for such applications, including IEEE802.15.6 (BAN) for body area networks, IEEE802.15.4 (Zigbee) and Bluetooth Low Energy (BLE) for sensor networks and(More)
Rapid developments of energy harvesting in the past decade have significantly increased the efficiency of devices in converting ambient free energy into usable electrical energy, thus offering opportunities to design energy autonomous systems nowadays. To achieve such energy autonomous systems, a good understanding of the harvesting capability from the(More)
This paper presents a wide-range low-power fully integrated fractional-N PLL. The PLL consumes 1.13mW to 1mW at 1.2V supply voltage, in a wide frequency range from 1.7GHz to 2.5GHz. It achieves up to -115 dBc/Hz phase noise at 1MHz offset and up to 2.5 degrees RMS phase error. The settling time is 40μs. The PLL is implemented in 90nm CMOS. The PLL(More)
The main bottleneck to achieve energy autonomy in body area networks (BAN) is the design of an ultra low power yet reliable wireless system. In this paper, we first demonstrate the feasibility of an ultra low power receiver by presenting our implemented receiver chip that could operate on a total power of 479.5 uW, which is more than one order of magnitude(More)
Sensor, actuator, and radio constitute the three basic components in a building automation system. Among all the three, radio consumes a significant part of the total power. In this paper, an ultra-low power event-driven radio is proposed as a solution to minimize the power consumption of a building automation system. Generic system architecture is(More)
This paper presents an ultra low power superregenerative RF front-end for wireless body area network (WBAN) applications. The RF front-end operates in the 2.36–2.4 GHz medical BAN and 2.4–2.485 GHz ISM bands, and consumes 500 mW. It supports OOK modulation at high data rates ranging from 1–5 Mbps. It achieves a sensitivity of −67(More)
Super-regenerative receiver is one of the potential candidates to achieve ultra low power wireless communication in body area network (BAN). The main limitations of the super-regenerative receiver include the difficulty in choosing a good quench waveform to optimize its sensitivity and selectivity, and its significantly degraded performance in the presence(More)
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