Waveguide-fed, slot and aperture-coupled patch arrays suitable for a radiometer operating at K-band have been studied. Using such antennas, an electrical scanned thinned array radiometer (ESTAR) operating at 18.7 GHz can be built with dual linear-polarization and conical-scan capability. Green's functions involving spatial and spectral domain variables have been derived and used to obtain the current on the patches and the coupling apertures. Computer simulation code using triangular basis functions are developed to analyze slot-patch radiating elements. The simulation is verified with empirical data and published data. Prototype arrays were built and measured. Design curves based on the simulations are also derived. |