The Design Of Silicon-based Passive Integrated LC Lumped Filter

Through taking silicon-based passive integrated device as research object, this paper starts with film magnetic core material, and then studies CoNbZr soft magnetic material, furthermore, its performance is also inspected and optimized after design and preparation. Besides, silicon-based passive planar spiral inductor and silicon-based LC lumped filter are focused. The design and computing method of both devices are studied respectively, and the simulation of ADS and HFSS is conducted accordingly, so as to analyze the simulation result, and optimize the performance of device. Specially, the progresses obtained in this paper are as follows:First of all, the characteristics of the integrated passive device are analyzed and demonstrated, the research emphasis of this paper is also put forward, and silicon-based integrated LC passive filter is designed. Besides, the manufacturing technology of passive device is analyzed, at last silicon-based CMOS technology is selected through comparing their advantages and disadvantages.Secondly, the preparation of magnetic core material is studied. After analyzing the influence of magnetic core material parameter on planar inductor performance, CoNbZr soft magnetic alloy film is prepared with the method of DC magnet sputtering, and then the performance of soft magnetic film is compared under different preparation conditions, so as to optimize the sputtering deposition conditions, finally, it can be obtained that coercivity is 6.22 Oe, permeability reaches up to 100.Thirdly, planar spiral inductor and MIM capacitor are researched. Equivalent model of spiral inductor and MIM capacitors is obtained through model analysis of them. And then computational formula of inductor and MIM capacitors is proposed through analysis of model. At last, through modeling and simulation of two devices by utilizing HFSS software and combining feasibility of the technology of silicon-based CMOS, plane tubular spiral inductor whose inductance value is 13 nH and quality factor reaches up to 20, plane spiral inductor with magnetic core whose inductance value is 100 nH approximately and quality factor reaches up to 100, as well as on-chip capacitor whose capacitance is at the level of pF, and quality factor within operating frequency is above 10 can be designed, so as to meet the design requirement of integrated LC filter.Fourthly, the design method of LC filter lumped filter is studied, meanwhile, Butterworth filter response is also described in detail. π-type LC low-pass filter is designed by utilizing ADS software, and the simulation of ADS circuit model and HFSS three electromagnetic field model is conducted, and compared. it can be concluded that the LC low-pass filter’s cut-off frequency of passband is 470 MHz, pass-band insertion loss is less than 0.5dB, and stopband loss is greater than 30 dB.