Analysis and design of coplanar waveguide-fed slot antenna array

A method for analyzing and designing the slot antenna array excited by a coplanar waveguide (CPW) is presented. The slots are etched on the conducting plane of the CPW and placed in the direction perpendicular to the transmission line. Moment-method analysis and matrix-pencil approach are adopted to calculate the scattering parameters and hence the self-admittance of each slot. The mutual admittances between the slots are calculated from the formulas derived for the complementary strip dipoles based on the reciprocity theorem and via Booker's relation. Then the transmission line theory is used to calculate the input impedance of the array, and an iterative process is employed to obtain a matched design for a desired slot-voltage distribution. A four-element slot array is fabricated and measured using this design procedure. Calculated results are in good agreement with measurements.