The X-band behaviour of a seven-section parallel-coupled microstrip band pass filter and microstripline due to thin-film Al2O3 overlay of different thickness is reported in this paper. This Al2O3 film can give a homogeneous overlay structure. There is a substantial increase in the bandwidth due to the overlay. the pass band extending towards higher frequency side. https://www.bekindtopets.com/flash-find-Expansion-Board-2-0-for-Pycom-IoT-Development-Boards-Discontinued-clearance/