SIW Corporate-Feed Network for Circular Polarization Slot Array Antenna

In this paper, multilayer feeding network for linear slot array antenna is studied. A substrate integrated waveguide (SIW) corporate-feed network for linear slot array antenna based on three layers is presented. This design has eight right-handed circularly polarized radiation elements, one power divider with SMA connector to SIW adapter structure and six SIW power divider by coupling slot method. The feed network and antenna structures has been designed at X-band frequency. The SMA to SIW power divider and SIW power divider by coupling slot has in-phase and out-of-phase feature, respectively. The proposed feeding method takes the advantages of miniaturization of structure compared with the corporate-feed network by T-junctions. Also, proposed network for feeding radiation elements, eliminated undesirable surface current of the coaxial connector transition, which reduction of these currents causes lower side-lobe level at the antenna radiation pattern. Dimensions of manufacture array structure are 132.8 * 23 * 2.4 mm³ and the substrate is Rogers RO4003c. This antenna has the capability to expand the number of elements and feed network for achieving higher gain. Due to the unidirectional radiation pattern, this antenna useful for monopulse radar and automotive radar applications.