This paper presents a low-power RF receiver/transmitter front-end for 2.4-GHz-band IEEE 802.15.4 standard in 0.18-m CMOS technology. An RF receiver comprises a single-ended low-noise amplifier, a quadrature passive mixer, and a transimpedance amplifier. A current-mode passive mixer showing a very good 1 noise performance is adopted to convert an RF signal directly to a baseband signal. Moreover, this type of passive mixer shows high-linearity performance, leading to overall RF receiver linearity improvement. A low-power, high-linearity transmitter front-end is implemented by using a passive mixer and two-stage driver amplifier in which the first stage is a conventional cascode amplifier and the second stage uses a folded cascode one. The receiver front-end achieves 30-dB voltage conversion gain, 7.3-dB noise figure with 1 noise corner frequency of 70 kHz, 8-dBm input third-order intercept point, and +40-dBm input second-order intercept point. The transmitter front-end shows 12-dB power conversion gain, 0-dBm output power with 10-dBm output third-order intercept point, and 30-dB local-oscilator suppression. The receiver and transmitter front-end dissipate 3.5 and 3 mA from a 1.8-V supply, respectively.Index Terms-CMOS radio, dc offset, driver amplifier (DA), IEEE 802.15.4 transceiver, low-noise amplifier (LNA), low power, 1 noise, passive mixer, transceiver front-end.

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A new wake-up receiver is proposed to reduce energy consumption and latency through adoption of two different data rates for the transmission of wake-up packets. To reduce the energy consumption, the start frame bits (SFBs) of a wake-up packet are transmitted at a low data rate of 1 kbps, and a bit-level duty cycle is employed for detection of SFBs. To reduce both energy consumption and latency, duty cycling is halted upon detection of the SFB sequence, and the rest of the wake-up packet is transmitted at a higher data rate of 200 kbps.The proposed wake-up receiver is designed and fabricated in a 0.18 µm CMOS technology with a core size of 1850x1560 µm for the target frequency range of 902-928 MHz. The measured results show that the proposed design achieves a sensitivity of 73 dBm, while dissipating an average power of 8.5 µW from a 1.8 V supply.Index Terms-Duty cycling, fast turn on/off, latency, low power, wake-up receiver, wireless sensor node.

The objective of this study was to investigate factors related to carcass traits of Hanwoo. In the statistical model developed in this study, slaughterhouse, carcass year, carcass month and sex effects were used as fixed effects and carcass traits (carcass weight, marbling score, loineye muscle area, backfat thickness and meat yield index) as covariations. The grading service data for 285,515 Hanwoo, which were evaluated by Animal Products Grading Service from 2005 to 2007, were used in this study. The partial R-square values of the fixed effects and the marbling score (MS), loineye muscle area, back-fat thickness, meat yield index and carcass weight (CW) on auction prices (AP) of the carcass and carcass price (CP) of the animals were estimated. The most important estimated trait in AP was MS. However, CW is the most important estimated trait on the CP and the MS also has secondly significant effect on the CP. In conclusion, MS as well as CW should maximize the farmer profits and establish a breeding scheme for Hanwoo.Key words: analysis of covariance, meat quality and quantity traits, auction price, total carcass price, Hanwoo