Design of Bragg Reflection Notch Filter for Microwave/Millimeter Wave Applications

A high power radiation of single millimeter wave frequency is used as axillary heating system on fusion research device. This source gives stray radiation and affects sensitive millimeter wave diagnostics components. Therefore, aband stop (notch) filter is required to remove the high power radiation from transmission line of the millimeter wave diagnostics system. A new type of notch filter of millimeter wave frequency is designed and developed. In this filter a Bragg reflection in circular corrugated waveguide is used as band stop in the transmission line. For this the corrugation period, depth and width for given diameter of the waveguide is determined by theoretical calculation and numerical simulation. The numerical simulation shall be done in COMSOL multi-physics RF module and CST microwave studio to validate the design parameter. The waveguide will be fabricated according to calculated dimensions. The fabricated waveguide will be tested for transmission characteristics.