A multi-band open-ended waveguide antenna by using groove loading technique

A new multi-band frequency response controlling method using groove loading technique on the narrow wall of an open-ended waveguide is proposed by the authors. The feature of this scheme is a larger stopband spacing that is independent of the position of the loading structure. A tri-band antenna is designed as an example to verify the effectiveness of the idea. Two notches are introduced, and the bandwidths, as well as stopband spacings, can be adjusted by independent parameters. The tri-band prototype can be fabricated using 3D printing technology or machining technology. Reasonable agreement between the measured and simulated results of impedance and radiation characteristics have been achieved.