Single and double folded-slot antennas on semi-infinite substrates

Design guidelines are presented for single and double folded-slot (DFS) antennas on a dielectric half-space. The DFS antenna consists of two folded-slot elements which are separated by a half-wavelength and are fed from one side using a coplanar waveguide transmission line. A space-domain integral equation technique, based on the free-space Green´s function, has been used to compute the resonant circumference and self- and mutual impedances of single folded-slots on various substrates. In addition, the input impedance and radiation patterns of DFS designs are included. Specific examples are shown for air, quartz, and silicon substrates, and measured data for DFS antennas on air and silicon substrates is provided to validate the calculated results