New Design Procedure to Determine the Taper Transition for Impedance Matching Between Microstrip Line and SIW Component

Abstract Normally the physical dimensions of the taper transition that realizes the impedance matching between the impedance of the feeding line built in microstrip line technology and the impedance of the component built in Substrate Integrated Waveguide (SIW) technology are obtained by computational optimization processes due the difficulty of analytical treatment. This research work presents a new empirical approach to determine all the physical dimensions of this particular planar transition without using any computational optimization process. The well-defined design procedure is based on an approximation according with electromagnetic simulations and electromagnetic theory. The main goal is to facilitate the integration between SIW technology and planar circuits. The whole design procedure considers central frequency for the recommended bandwidth in the TE10 propagation mode and power-voltage impedance definition for the SIW. Two structures are designed on RT/duroid 5880 to operate in the X band and Ku band, and the frequency response for both structures are compared by electromagnetic simulation and experimental results. The structure operating in X Band demonstrated return loss better than 10.0 dB at 61.67% of the considered bandwidth and the structure operating in Ku Band demonstrated return loss better than 10.0 dB at 72.88% of the considered bandwidth.