Scanning Leaky-wave Antenna based on a Waveguide filled with Plasma-like ENG Metamaterial

Recently, it has been shown that a waveguide filled with a uniaxial thin-wire-based ENG filling supports low-loss backward propagation below a cut-off frequency of the fundamental TM₁₁ mode. If the plasma frequency of an ENG filling is chosen to be equal to the cut-off frequency of TM₁₁ mode, the waveguide supports three different modes of propagation: the backward-wave mode, the mode with zero propagation factor (but with non-zero group velocity) and the forward-wave mode. This paper reports preliminary experimental results of use of such a waveguide as a leaky-wave antenna with back-fire to end-fire scanning capabilities. The experimental antenna based on a slotted waveguide with thin-wire-based ENG filling, operating in 10 GHz band, was successfully designed, manufactured and tested. Preliminary results revealed a scanning angle of plusmn 60 degrees from broadside for the slotted waveguide with six unit cells