Hybrid waveguide-stripline feeding networks for Ka-band and millimetre-wave arrays

In this paper a hybrid technology that combines striplines and E-plane metallic waveguides for efficient feeding networks at millimetre-wave is proposed. Even though the hybrid structure can be used to design both series and parallel feeding networks, in this paper the attention is focused on series fed arrays. In what follows, the design of a travelling wave power divider operating in the Ka-band is reported. The power divider is used as main feeding line to design a 4times4 Ka-band array of circular waveguides. Details on the design of the array elements and on the realization of the overall structure are given. Measured results show that the hybrid waveguide/stripline structures are a promising technology to realize efficient feeding networks for arrays operating at millimetre-wave frequencies.