| Summary: | 碩士 === 國立成功大學 === 電機工程學系碩博士班 === 94 === This thesis aims at the design of a 0.18 um CMOS VCO circuit for the RF tuner in the DVB-T/H system. Since the RF input frequency of a digital TV (DTV) ranges wide from 48 MHz to 860 MHz, the tuning range of the VCO has to be wide enough. Meanwhile, the DTV system requirement of phase noise better than -85 dBc/Hz at 10 KHz offset frequency forces the VCO to have a low phase noise performance. Although the tuner IC can be implemented by bipolar, GaAs, or BiCMOS technologies, the most effective way to achieve the target of low cost and high integration is still by the CMOS technology. By this way, to integrate the whole digital TV system into a single chip becomes very possible.
We try to develop a set of CMOS VCO circuits with wider tuning range and lower phase noise. By making use of switched inductors and switched capacitors, we wish to drive the tuning range of each single VCO up to 400 MHz and to fit for the stringent requirement of phase noise of -85 dBc/Hz at 10 KHz offset. Therefore, the numbers of VCO’s used in the tuner IC can be reduced greatly from 6~8 to 2~3. By applying a newly proposed switched differential inductor developed from our laboratory, the integrated VCO circuit can occupy a smaller chip area and leads to the reduction of cost.
The innovatory contributions of this thesis are as followed: The first, we propose the full integration of a wide tuning range VCO circuit with a proposed switched differential inductor. The second, we confirm the integration possibility of VCO’s for the tuner IC in a number of two or three.
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