US Patent 10224644 Series-fed E-shaped patch antenna array with co-polarized parasitic patches

A series-fed E-shaped patch antenna array has co-polarized parasitic patches to improve aperture efficiency. Each of microstrip parasitic patches is inserted between a plurality of microstrip E-shaped patch antennas. The parasitic patches are co-polarized with the E-shaped patch antennas so that the current flows in the parasitic patches and the E-shaped patch antennas have the same polarity. Additional radiation from the co-polarized microstrip parasitic patches significantly improves gain flatness, gain and aperture efficiency due to offset resonance frequency.