A new kind of leaky circular waveguide with periodic slots and wire ridge

Transmission loss of the leaky coaxial cable (LCX) increases with operating frequency. In order to reduce the transmission loss, circular waveguide is used to replace the coaxial cable in microwave band. Similarly, to reduce the transmission loss of the leaky wave structure, leaky circular waveguide is used. However, due to rotating symmetry, the polarization plane of the dominant mode TE11 in circular waveguide may rotate circumferentially. So a wire ridge is added to the leaky circular waveguide in this paper to break the rotation symmetry of the circular waveguide. The near field and coupling loss of the new kind of leaky circular waveguide with periodic slots and wire ridge are calculated and discussed. The results show that parameters of the slots have significant influence on the aperture field and coupling loss, and therefore, it is possible to design leaky waveguide with desired coupling loss by choosing slot parameters properly. The new leaky waveguide can be used to distribute radio wave at higher frequency.