Composite right/left-handed leaky-wave transmission-line with switchable polarization capability

In this paper a two port composite right/left-handed (CRLH) leaky-wave (LW) transmission-line (TL) is introduced that has the capability of switching between two orthogonal polarizations while operating in the fast-wave region. This switchable functionality is achievable based on the configuration of the unit-cells in use for the proposed structure. Each proposed unit-cell consists of two orthogonal CRLH portions and two orthogonal microstrip sections. Each microstrip section is in parallel to one of the CRLH portions. The active propagation path of the unit-cell includes only one CRLH and one microstrip portion. Depending on the chosen propagation path of the CRLH portion followed by the microstrip section or vice versa, two orthogonal radiating field polarizations can be obtained. For illustration purposes, an 8-cell two port CRLH LW-TL based on the proposed unit-cell is simulated, fabricated and measured and the obtained results verify the unique switchable polarization feature of the structure.