【作者】 菅端端；

【导师】 肖夏；

【作者基本信息】 天津大学 ， 微电子学与固体电子学， 2007， 硕士

【摘要】 由于片上螺旋电感具有低成本和易集成的特点,所以广泛用在硅基射频集成电路里。作为电路模拟不可缺少的单元,片上电感的等效电路模型应该能在电路模拟中准确反映出电感的电学特性,但是片上电感结构的复杂性和高频时的各种寄生效应却使得模型很难精确,并已成为射频集成电路设计者面对的主要挑战之一。本文主要针对电感Q值的提高和精确模型的建立展开讨论。为了获得精确的电感模型,首先分析了螺旋电感的损耗机理,同时总结了提高电感Q值的各种方法。然后,提出了一个简化的2-PI等效电路模型,它综合考虑了趋肤效应、邻近效应、线间寄生电容、容性衬底耦合、感性衬底耦合等等高频寄生效应。同时给出了模型中元件的估值公式,这些结果可用作SPICE拟和的初始值。模拟结果表明,该简化模型在很宽频率范围内与专用电感仿真工具——ASITIC模拟结果相吻合,并提出了一种片上电感综合和优化方法。最后,基于上述方法和频率合成器中压控振荡器的要求,设计了一系列的片上螺旋电感,并最终完成电感电容压控振荡器设计(包括电路与版图设计)。Spectra模拟结果表明:基于UMC 0.18μm工艺,使用经过优化电感的压控振荡器相位噪声在600KHz时达到-121.25dBc/Hz,这比相同电路使用UMC提供的电感降低了5dB。更多还原

【Abstract】 IN silicon-based radio-frequency (RF) integrated circuits, on-chip spiral inductors are widely used due to their low cost and ease of integration. As a necessary element for circuit design, equivalent circuit models of spiral inductors should efficiently represent their electrical performance for circuit simulation, but model inaccuracy, which stems from the complexity of on-chip inductor structures and high-frequency phenomena, presents one of the most challenging problems for RFIC designers. So we focus our discussion on the improvement of spiral inductors’quality factor and the building of precise models.In order to make an accurate inductor model, the loss mechanisms of spiral inductors are analyzed and some main kinds of methods for improving Quality factor of spiral inductor are summarized at the same time. Then a simplified 2-PI model of planar spiral inductor is presented, which include the effects of Skin effect, Proximity effect, line-line parasitic capacitance, capacitive substrate coupling, inductive substrate coupling, and so on. The formula is given for estimating the components in the model, and the estimated value can be used as the initial value for fitting process in the SPICE, which can make the fitting process efficiently. According to the simulation, the simplified modeling methodology shows excellent agreement with the results of the electromagnetic field solver (ASITIC) over a wide frequency range, and a method of synthesis and optimization for spiral inductor is presented.At last, on the basis of the method above and the requirements of frequency synthesizer, a series of spiral inductors are synthesized and optimized. The simulation result demonstrates that the phase-noise of VCO is -121.25dBc/Hz@600KHz on UMC.18μm process, which is 5dB better than the inductors supplied by UMC.更多还原