Directional Antennas, directionality, input energy, limited frequency range, bandwidth, weight, efficiency, design complexity, operating frequency range, GPS Antennas, point-to-point microwave, millimeter-wave backhaul links, Panel and Patch Antennas, electromagnetic compatibility testing, Yagi Antennas, SCADA, Gain Horn Antennas, coaxial-to-waveguide adapter, certification, compliance, measurement