A Novel Design of a SIW-Fed Antenna Array Using an Accelerated Full-Wave Methodology

Arrays fed by substrate-integrated waveguides (SIWs) are a current topic of interest. However, most designers have to rely on general-purpose commercial software, usually inefficient for multiple full-wave simulations in a design process. This work proposes a new fast full-wave strategy, with very low iteration times, based on the simultaneous use of addition theorems for spherical and cylindrical modes. After a domain decomposition of the array into fixed or modifiable (to be optimized) sections, each section is analyzed using a finite-element/modal analysis to obtain its general scattering matrix. Fixed sections are only once coupled at the beginning, while each optimization iteration is calculated with full-wave precision by adding the interactions with the modifiable sections. A complete design process of a novel 16-slot progressive-wave SIW-fed array is performed to validate the strategy usefulness. 112800 iterations, with 47 optimization variables, are calculated in under 4 h (speed-up factor of over 2000 compared to general-purpose commercial software). The designed device is manufactured and experimentally characterized, measuring a 1.05 GHz
$\vert S_{11} \vert $
bandwidth under −10 dB and a maximum gain of 15.6 dBi at
$\theta =-11^\circ $
in the array plane.