The Hidden Component of High Speed Filter Design: The Footprint Influence

摘要

It is very intriguing to design passive filters in a very small package, in the frequency domain of 10 GHz and above.rnModeling the device footprint and correctly incorporate the model in the design work to design passive filter is keyrnto successfully manufacture surface mount filter components that perform as expected, once they are mounted to thernprinted circuit board. This requires accurate correlation to the filter model and the measured first articlerncomponent. In this work we studied footprint and it’s influence in the final product. We developed filter designrnprocedure using simulation software. We considered the impact of the parasitic of the input signal lines, printedrncircuit board’s footprint parasitic, and filter’s signal launch pad loss. We discussed an efficient way to design lowrnpass passive filters in Ball Grid Array package; we optimized the design flow to manufacture filters. Then werndesigned and manufactured 12 GHz 9th order absorptive low pass Bessel filter, whose size is 2.0 mm X 7.1 mm. Werncompared the measured data of the fabricated filter with the simulation results. We discussed the use of CoaxialrnMeasurement Modules, which contains the filter with optimized design footprint.