How does the radiation pattern of a horizontally-polarized antenna mounted above a long slope compare with the same antenna mounted above flat ground?
The main lobe takeoff angle increases in the downhill direction
The main lobe takeoff angle decreases in the downhill direction✓Bonne réponse
The horizontal beamwidth decreases in the downhill direction
The horizontal beamwidth increases in the uphill direction
Explication
Ground that falls away in front of the antenna sits farther below it than flat ground would, so the reflection point moves outward and the interference maximum forms closer to the horizon. The main lobe in the downhill direction therefore takes off at a lower angle than over level ground.