Microwave filter for below cut-off waveguide - is formed by screws having dia. between 0.35 and 0.5 of guide width

摘要

The microwave filter is for use with wave-gudes operating at a frequency below their H10 limiting frequency. Such a filter is constructed by placing screws (2) in the broad side of the rectangular wave-guide (1). The ratio of screw dia. (d) to guide width (a) is chosen to give d/a between 0.35 and 0.5. This ratio is found to give the best filter performance. Fine tuning can be obtained by drilling and tapping the main screw (2) and inserting a smaller dia. one (3) to give the close adjustment.