A composite circularly polarized dielectric complex waveguide slot antenna array with enhanced bandwidth

A novel Ka-band composite circularly polarized dielectric complex waveguide slot (CP-DCWS) antenna array is designed, fabricated and measured. The CP-DCWS antenna array is composed of a circular polarization grid, a slot microstrip line, a groove guide and feeding network. The slot microstrip line is formed by a metal clad dielectric substrate and slots etched in the metal. This antenna array not only maintains the advantages of the traditional waveguide slot antenna array, but also has the characteristics of wide bandwidth. The measurements show that the radiating efficiency of the CP-DCWS antenna array is 80%, which is almost the same as the traditional waveguide slot antenna array, and the bandwidth of the CP-DCWS antenna array is 700 MHz, which is 200 MHz (40%) wider than the traditional waveguide slot array antenna. Measured results are in good agreement with electromagnetic simulations.