A doubly corrugated filter was designed for a combined multi-feed microwave-hot air and continuous belt system (CMCB). The proposed filter reduces microwave energy radiation from the open entry of the continuous belt system. Microwave radiation leakage that affects a human should remain below 10 mW/cm2 . The filter was designed for stop-band frequency range 2,300-2,600 MHz, while the operating frequency is 2,450 MHz, and for attenuation greater than 60 dB in this range. We report on optimizing all the design parameters of a doubly corrugated filter and on experimental verification after its installation at the Research Center of Microwave Utilization in Engineering (R.C.M.E) at Thammasat University, Thailand.
