Huancheng Li

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A low-phase-noise and low-cost millimeter-wave voltage-controlled oscillator (VCO) has been fully integrated in commercial SiGe bipolar technologies. By varying the bias voltage of the on-chip varactor, the frequency can be continuously tuned from 43.6 to 47.3 GHz. In this frequency range, single-sideband phase noise between -103 and -108.5 dBc/Hz at 1 MHz(More)
It is demonstrated that SiGe bipolar preproduction technologies are well suited for VCOs in 77 GHz automotive radar systems. Due to the relatively high output power aimed at, the designer has to consider the physical transistor limits carefully. The VCOs need a single supply voltage only and have been fully integrated (including resonant circuit and output(More)
Multipurpose VCOs with wide tuning range and oscillation frequencies up to 74 GHz (on wafer) and 69 GHz (mounted chip, with output buffer), respectively, have been fully integrated in a commercial SiGe production technology. To the best of the authors' knowledge these are record values for commercially available Si-based technologies, despite the moderate(More)
Article history: Received 19 August 2008 Received in revised form 29 November 2008 Accepted 4 December 2008 Available online 12 January 2009 A GIS-based approach was designed to spatially estimate direct use value of ecosystem services and tomap results for a case study at county scale. The approach highlights the use of GIS to collect data, perform spatial(More)
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