A Miniature 2.4GHz ‘L shaped’ Microstrip Band Stop Filter with Spur microstrip line and Via-hole grounding

With the rapid development of present communication technology, there has been a growing need in microwave devices for communication applications. The Microstrip band stop filter is used to reject higher harmonics and spurious response for microwave frequency application. In this paper, improved performance and compact size microstrip band stop filter have been designed at 2.4 GHz. The compact size is achieved through spur microstrip line and via-hole grounding. The λ/2 open-ended stubs are converted to λ/4 one sided short-circuited stubs using via-holes and the spur microstrip lines are used to reduce the number of resonators in the filter. The total length of the filter is reduced from 126 mm to 45 mm, and the -6dB rejection bandwidth is enhanced by 14%. The frequency of the band stop filter is around 2.4 GHz, so it is used for Wi-Fi application.