Yao-Hong Liu

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This paper presents a 400-MHz energy-efficient offset quadrature phase-shift keying (O-QPSK) transmitter for implantable multichannel neural recording applications. Transmitters for these applications must operate at low power while delivering a high data rate. The proposed transmitter incorporates a phase MUX, which directly implements the phase-shift(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)
A low-power super-regenerative receiver (SR-RX) with a digitally-controlled oscillator for the capsule endoscope system is reported in this paper. In this work, an open-loop frequency calibration loop is proposed to adjust the oscillator center frequency to the desired frequency band. The RX operates in the 402-405 MHz MICS band, and is designed to receive(More)
Abstract—this paper reports a PFD/CP linearization technique and a new charge pump circuit to enhance the performance of a delta-sigma (∆Σ) fractional-N PLL. The proposed method improves the PLL linearity by forcing the PFD/CP to operate in a linear part of its transfer characteristic; while the CP circuit minimizes the current mismatch between the up and(More)