Design Of S-band Narrow-band Bandpass Baw Filter

The BAW filter composed of FBARs can meet the requirements of high performance RF front-end filtering,and it's a new solution for RF filter.According to the design specifications given by the XX organization and the process constraint conditions,a S-band narrow-band bandpass BAW filter with center frequency 2.46 GHz,bandwidth 30 MHz,insertion loss-1.154 dB,passband ripple 0.9 dB,the out-band rejection about-42.5dB@ 2.390 GHz;-45.5dB@ 2.500 GHz was designed.Each designed specification value of filter was better than it in specification requirement.The designed filter had a lower band insertion loss and higher out band rejection,could meet the application of the current S band wireless communication.The main work includes:In chapter 3,By adjusting the thickness ratio of the electrode and piezoelectric layer,the thickness parameters of the FBAR film with higher k2 eff and smaller size was detemined.The parasitic mode was suppressed by the method of electrode apodization,meanwhile the method improved the Q value of FBAR effectively.In chapter 4,an S band BAW filter which meet the specifications(bandwidth,center frequency,out of band rejection and band loss)was designed and optimized.An external inductor was used to improve the out band rejection of the designed BAW filter.In chapter 5,the BAW filter layout was designed.The layout shape can help to decrease the parasitic inductance,parasitic capacitance and ohmic loss on the performance of BAW filter.In order to evaluate the performance of the designed S band BAW filter used Mason model,an acoustic-electromagnetic co-simulation model of the BAW filter was established based.Because the ripple value in band didn't meet the specification,the structure parameters of BAW filter were redesigned until the results through verified successfully.According to the layout,the processing flow and the layout of the photolithographic masks of the BAW filter were designed.The main innovation points as follows: The conclusion was obtained that when the the inductance seriesed with the largest area of parallel FBAR,the inductance value is minimum.The method of BAW filter's layout ruler was presents and validates.An acoustic-electromagnetic co-simulation model of BAW filter was established.