Design and analysis of a microwave band reject filter using a double magic tee

This paper presents the implementation of a band reject microwave filter at X-band (8 GHz–12.4 GHz). The design is supported by necessary theory. The calculated filter response resembles the experimental frequency response of the band reject filter (BRF). Typical centre frequency of operation of this BRF is 10 GHz and it has a flat bandwidth of 250 MHz. The band reject filter is tunable. It can be tuned by varying the length of the sliding short.