| Summary: | 碩士 === 國立中正大學 === 電機工程所 === 97 === Two novel voltage-controlled oscillators (VCOs) are designed for the
fourth-generation and WiMAX applications, which are the differential VCO with
double-gate coupling (DGC-VCO) technique and the current-reused VCO with
auto-transconductance matching (ATM-VCO). In DGC-VCO, the gate and bulk of
transistor are coupled simultaneously for greater transconductance, leading to lower
power consumption. The VCO is implemented with 0.18-μm CMOS technology. The
measured tuning range is 3.02 to 3.89 GHz and the phase noise is -93 dBc/Hz at
1MHz offset from 3.02 GHz. The single-ended output power is -4.1 dBm with 6 mW
power consumption in VCO core. The figure of merit is -156.1 For ATM-VCO, the
signal, which is center-tapped from the tank inductor, is fed to the source degeneration
resistor such that the transconductances of PMOS and NMOS are automatically
matched. Therefore, the amplitude imbalance can be dramatically improved. The
measured tuning range is 2.93 to 3.62 GHz, where the amplitude imbalance is 8-9% .
The phase noise is -112.8 dBc/Hz at 1MHz offset from 2.93 GHz. The output power is
-4.3 dBm with 1.95 mW power consumption in VCO core. The figure of merit is
-179.4.
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