A Novel Design for a Circular Waveguide Directional Coupler

Gentili, G. G.; Lucci, L.; Nesti, R.; Pelosi, Giuseppe; Selleri, Stefano

doi:10.1109/TMTT.2009.2022886

In this paper, a study of the coupling between a rectangular waveguide and circular waveguide is presented, aimed at developing a design procedure for a rectangular to circular waveguide directional coupler. Since radio-astronomical receivers often exploit circular horns, a coupler sharing the same waveguide type is at a premium, and furthermore, it reduces the feeding network complexity in dual polarization applications. A novel approach for obtaining traveling wave modal amplitude coefficients is presented, suitable for modes of any order. This approach is used to analyze the behavior of a single hole coupler between a rectangular and circular waveguide. From this starting point, a four holes directional coupler with good performance is designed in the 22-GHz band. Measurements and full-wave numerical simulations show excellent agreement with the proposed theory

A Novel Design for a Circular Waveguide Directional Coupler / G.G. Gentili; L. Lucci; R. Nesti; G. Pelosi; S. Selleri. - In: IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES. - ISSN 0018-9480. - STAMPA. - 57:(2009), pp. 1840-1849. [10.1109/TMTT.2009.2022886]