A dual-band power divider based on higher-order modes of spoof surface plasmon polaritons

In this paper, a dual-band power divider is presented based on the propagation of the higher-order modes of spoof surface plasmon polaritons (SSPPs). A hollow rectangular groove is introduced as a unit cell, and its dispersion characteristics for higher modes and the fundamental mode are examined. Compared with the traditional rectangular groove unit cell, the proposed unit cell provides extreme electromagnetic wave confinement for higher-order modes. In addition, the second and fourth modes are even and can be excited by a coplanar waveguide. By utilizing the even modes of the proposed unit cell, a dual-band transmission line and a dual-band power divider are designed so that the operating bands can be controlled by the inner and outer depth of the grooves. The dual-band SSPP transmission line and the dual-band power divider are manufactured and tested to validate the design procedure. Finally, the measurement results show good agreement with the simulations, demonstrating the effectiveness and robustness of the design procedure