Fig. 1. Layouts of SSPPs unit structure. (a) Conventional groove structure; (b) proposed Yagi-like antenna structure

Fig. 2. Simulated dispersion curves of SSPPs unit. (a) Conventional groove structure; (b) proposed Yagi-like antenna structure

Fig. 3. Simulated electric field distributions of SSPPs unit. (a) Electric field distribution of conventional groove-based SSPPs unit for mode 0; (b) electric field distribution of conventional grooves-based SSPPs unit for mode 1; (c) electric field distribution of SSPPs unit of proposed Yagi-like antenna structure for mode 0; (d) electric field distribution of SSPPs unit of proposed Yagi-like antenna structure for mode 1

Fig. 4. Simulated dispersion curves of SSPPs unit of Yagi-like antenna structure varying with structure size under different structure parameters. (a) For different width l; (b) for different length h

Fig. 5. Configuration of SSPPs high-order mode of Yagi-like antenna structure

Fig. 6. Simulated results of proposed filter based on Yagi-like antenna structure SSPPs

Fig. 7. Simulated return loss S₁₁ of the proposed filter based on SSPPs high-order mode varying with line width W₁

Fig. 8. Simulated insertion loss S₂₁ of proposed filter based on SSPPs high-order mode varying with array number N of SSPPs unit

Fig. 9. Simulated electric field distributions of proposed filter based on Yagi-like antenna structure SSPPs. (a) 4 GHz; (b) 8 GHz

Fig. 10. Test environment of proposed filter based on Yagi-like antenna structure SSPPs

Fig. 11. Measured and simulated loss parameters of proposed filter based on Yagi-like antenna structure SSPPs