Xiaozhou Yan

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A 2.4-GHz energy-efficient transmitter (TX) for wireless medical applications is presented in this paper. It consists of four blocks: a phase-locked loop (PLL) synthesizer with a direct frequency presetting technique, a class-B power amplifier, a digital processor, and nonvolatile memory (NVM). The frequency presetting technique can accurately preset the(More)
This paper presents a behavior model for PLL Frequency Synthesizer. All the noise sources are modeled with noise voltages or currents in time-domain. An accurate VCO noise model is introduced, including both thermal noise and 1/f noise. The behavioral model can be co-simulated with transistor level circuits with fast speed and provides more accurate phase(More)
This paper proposes a smart frequency presetting technique for fast lock-in LC-PLL frequency synthesizer. The technique accurately presets the frequency of VCO with small initial frequency error and greatly reduces the lock-in time. It can automatically compensate preset frequency variation with process and temperature. A 2.4GHz synthesizer with 1MHz(More)
A methodology is presented for predicting the phase noise of the ΣΔ Fractional-N Frequency Synthesize that is both accurate and efficient based on sampling the noise voltage in the time domain. An accurate Voltage Control Oscillator (VCO) noise model is presented, including both thermal noise and 1/f noise. The behavioral model provides a(More)
Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease strongly associated with HLA-B*27, an major histocompatibility complex (MHC) molecule that presents peptide antigen to T cells. Previously, regulatory B cells were found to suppress T cell-mediated autoimmunity induction and chronic inflammation, partially through interleukin (IL)-10(More)
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