Vco Based On Sige Technology Research And Design

In recent years, wireless communications system developed rapidly, at the same time, it demanded higher develop on RF IC design and research. The advancement of process and technology, leading to the realization of on-chip passive elements such as inductors and varactors, makes the on-chip implementation of voltage-controlled oscillators (VCOs) easy. Nowadays, fulfilling the noise and tuning range requirements with low power consumption is an important subject in the area of RF IC.Based on the structure theory of SiGe HBT,SiGe HBT SPICE noise model and BJT small signal model, an concise SiGe HBT model is deduced.In this thesis,the theory and practice of LC VCOs are analyzed, and many key technique parameters especially for the basic theory of phase noise are studied. Based on the mechanism of varactors, the relationship between gain and control voltage of LC VCO is studied, a method to improve the gain of the LC VCO is provided, and a design to optimize the linearity of VCO is proposed.The elements in the design are studied, noise models of these devices are deduced. Combining with proposed SiGe HBT noise model and PMOS transistor noise model, based on circuit analysis theory, the noise model of this design is obtained. And applying the linear time-varying phase noise theory, the phase noise model in 1/?2 region of this design is structured.According to the targets of low voltage-supply, low power consumption, low phase noise and large tuning range, based on TSMC 0.35μm SiGe BiCMOS process ,a VCO IC exhibiting a linear VCO gain (Kvco) for 5-GHz band application is presented. The VCO center frequency is 5.5GHz, oscillation frequency range is from 5.13 GHz to 5.93 GHz, the tuning range is 14.5 %, and the dc power consumption is 2.9 mW at a supply voltage of 3.3 V. The phase noise is -110 dBc/Hz at lMHz offset.