Design of Open-circuited Stub Butterworth Low-pass Microstrip Line Filter

This article designs a novel 2.5GHz Butterworth low pass microstrip line filter (MLF) by PCB prototyping machine. We could realize the theory, implement, and application of MLF in the same time .we design and simulate MLF circuit by IE3D software package. We choose FR-4 glass fiber PCB to make the MLF. We measure the S parameter frequency response of MLF by vector network analyzer.