Mode Composite Waveguide Based on Hybrid Substrate Integrated Waveguide and Spoof Surface Plasmon Polariton Structure

In this paper, a novel mode composite waveguide based on hybrid substrate integrated waveguide and spoof surface plasmon polariton (SIW-SSPP) is proposed. Through different feeding methods, the odd mode and even mode of SSPP are excited simultaneously and operate at the same frequency band. Thus, co-frequency mode multiplexing is achieved for the proposed odd-even mode composite waveguide (OEMCW). The design principle and characteristics of the OEMCW are analyzed in this work. A prototype is fabricated and measured to demonstrate its transmission performance. The measured results indicate that the proposed waveguide can operate from 10.3 GHz to 18 GHz in two modes with the isolation larger than 18 dB.