Assuming that it's really a free space path with no fresnel zone interference. If the antennas are correctly aligned for maximum gain, then using the theoretical main lobe gain is appropriate.

In FZA imaging system, the Fresnel zone plate is placed only three millimeters from the sensor. Jiachen and his colleagues took a series of pictures which are displayed on an LCD monitor.

“Optical Fresnel zone plate flat lenses made entirely of colored photoresist through an i-line stepper”, Light: Science & Applications, DOI: 10.1038/s41377-024-01725-6.

If Fresnel lenses interest you, we’ve taken a look in the past at their history. Posted in green hacks Tagged fresnel, lens, optics. Post navigation.

Sony avoided this problem in the original PlayStation VR by using traditional lenses in that headset's bulky drop-down visor, which floats in front of the user's eyes. For the upcoming PSVR2 ...