Design of Millimetre Wave Band Pass Filter for Radio over Fibre Application

enables them to support wider bandwidth thus high data rate. Band pass filters are important part of RF front end in radio transceivers. In this project, design of a band pass filter at 60GHz is performed. Waveguide filter type is chosen due to its ability to support filtering at high frequency with minimal loss and higher quality factor compared to other filter categories. The filter is a rectangular waveguide with circular inductive posts dispersed throughout its length making resonant cavities in between. The transmission mode is the dominant mode, TE10. MATLAB is used to find out the order of a butter-worth filter which can satisfy certain given requirements which turns out to be a 6th order. HFSS (High Frequency Structural Simulation) is used to model, simulate, optimize and tune the filter design. The designed filter has a bandwidth of 3GHz (58.5 to 61.5GHz), return loss between 15 to 20dB and insertion losses 54dB (at 57GHz) and 42dB (at 63GHz). From loss vs Frequency plots, it’s shown that the designed filter possesses high selectivity.