Investigations On The Substrate Integrated Waveguide And Its Applications In Slot Array Antennas

A rigorous full-wave approach based on the method of lines (MoL) is presented to analyze the propagation characteristics of substrate integrated waveguides (SIWs), in which a generalized matrix eigenvalue equation is derived instead of the conventional transcend equation, and then greatly improved the computing efficiency. The use of an efficient adaptive absorbing boundary condition, which is concluded from Z transform absorbing boundary condition (Z-ABC), further improved the accuracy of the calculated propagation constants. Some design curves and two empirical equations are proposed for the propagation constants of SIWs, which gives a simple but efficient tool in designing substrate integrated waveguide components.By etching longitudinal slots on the top metallic surface of SIW, integrated slot array antennas are formed. A fast algorithm about the resonant length of the slot and a substrate integrated dielectric constants measurement method facilitate the design procedure. Microstrip power divider or hybrid ring coupler is selected as feeding system to fabricate the whole system on a single substrate, which takes the advantage of small size, low profile, and low cost etc. The simulated and experimental results of a four-by-four SIW slot array antenna at X-band and a four-by-eight substrate integrated monopulse antenna are presented. At last, concepts of"low coupling"and"feed vertically"are introduced into SIW with a help of LTCC technology.