Fabrication and Evaluation of a Waffle Type Waveguide for Ku-Band Application

In this paper, we propose a waffle type waveguide for Ku-band application. For the first time, we fabricated and evaluated the waffle type waveguide. The waffle type waveguide consists of rectangular structure and waffle type structure for electromagnetic wave transmission and attenuation, respectively. Bosses are periodically arrayed horizontally in waffle type structure and they are confronted vertically each other with air gap, which act as a low pass filter. The waveguide operation in Ku-band was confirmed by finite element simulation. Moreover, the waveguide firstly fabricated by machining was evaluated by S-parameter measurements. As a result, the measurement results well agreed with the simulation ones. We firstly and successfully verified the operation of the waffle type waveguide. We also achieved low transmission loss, and low reflection below 20 dB over wide frequency range from 15.2 GHz to 23.0 GHz which corresponds to a 40.8% fractional band width.