Xueyang Geng

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—This paper presents a transformer-coupled varactor-less quadrature current-controlled oscillator (QCCO) RFIC covering the entire X-Band from 8.7 GHz to 13.8 GHz. The QCCO incorporates a transformer-coupled technique that achieves frequency tuning by varying the bias currents in the primary and secondary windings. Fabricated in a 0.18 m SiGe BiCMOS(More)
—This paper describes a 12-bit 300 MHz CMOS DAC for high-speed system applications. The proposed DAC consists of a unit current-cell matrix for 8 MSBs and a binary-weighted array for 4 LSBs. In order to ensure the linearity of DAC, a double Centro symmetric current matrix is designed by using the Q 2 random walk strategy. To minimize the feedthrough and(More)
direct digital synthesis (DDS) for chirp generation is presented. The radar chip, including receiver, transmitter, quadrature DDS, phase-locked loop (PLL) and analog to digital converter (ADC), has been implemented in a 0.13μm BiCMOS technology. The stretch processing technique is employed to translate the time interval between the received and the(More)
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