Based On Planar Integrated Waveguide Power Divider / Combiner Network Engineering

The rapid development of modern wireless-communication technology arouses some critical requirements on the RF/microwave devices and subsystems, such as low profile, miniaturization and high integration etc. Substrate-integrated waveguide (SIW) is a novel transmission line proposed in recent years; it takes the advantages of rectangular waveguide and microstrip line, and has aroused a lot of attention to its theoretical analyses and engineering applications. Folded substrate-integrated waveguide (FSIW) is an innovation based on SIW, which has been proposed recently and investigated theoretically, with approximately 50% reduction in width than the original SIW while keeping almost the same propagation characteristics. With more compact structure, FSIW can be used for the design of some novel RF/microwave circuit and system. In this work, these two structures are used to design microwave planar multi-way power dividing/combining networks.The common types of planar structure-series and parallel forms of power dividing/combining networks are discussed firstly. In our work, the series forms are employed in which the directional couplers are basic components. Three kinds of directional coupler are designed; they are SIW narrow-side coupling directional coupler, SIW broad-side coupling directional coupler, and FSIW broad-side coupling directional coupler. Based on these three kinds of directional couplers, three types of power dividing/combining networks are designed; the prototypes are fabricated and measured to verify the validity of the theoretical analysis and design strategies. We may note that, the horizontal dimension of the FSIW power dividing/combining network is almost 1/4 of the network based on SIW narrow-side coupling directional couplers, and 1/2 of the network based on SIW broad-side coupling directional couplers.