Band Gap Based Power Dividers in Parallel Plate Waveguide Technology

In this paper is described a novel and low-cost method for the realization of electromagnetic band gap (EBG) based power dividers in Parallel Plate Waveguide Technology (PPW). The proposed configuration can be employed as a basic element of the highly efficient Continuous Stub (CTS) array antenna feeding network. The resulting band-gap feeding network overcomes the problem of good electrical contact between the metallic layers thanks to the use of printed mushroom-type EBG embedded inside the PPW. The EBG is designed to provide a forbidden band that covers the operating frequency range of the waveguide, in this manner electromagnetic leakage from the air gap between layers is avoided simplifying the mechanical assembly of the antenna with a significant reduction of manufacturing costs and complexity. The metallic units of the CTS antenna can be easily fixed by screws, and no additional welding assembly is required. A design example operating in the 27.5-31 GHz band (Tx Satcom band) is presented and compared with a classical configuration. The proposed solution provides a good matching on the whole bandwidth, while the insertion loss remains unchanged.