The contribution of this article is to propose a balanced and unbalanced diplexers design using substrate integrated waveguide cavities (SIWCs). The employed SIWCs are square cavities which support two co-frequency degenerate modes. A row of via-holes is introduced inside the cavity to split the degenerate modes’ co-frequency resonances into two frequency-distinct ones, thus creating two duplexing bands with an auxiliary signal filtering effect. The fabricated diplexers performed quite well with measured and simulated results being in good agreement. The measured isolations between the two duplexing ports are more than 40 dB. Furthermore, the balanced SIWC diplexer has its measured common-mode rejection levels >42 dB, and the measured common-mode isolations between the two duplexing ports are >53 dB.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering