Simple formula for calculate antenna gain

[RF engineer]

hope this is useful
the gain can be estimated if the beamwidths are known:

G = 10 x log 31000/(V3 x H3)

G = Antenna gain relative isotropic antenna (dBi)

V3 = Vertical beamwidth relative -3 dB points (degree centigrades)

H3 = Horizontal beamwidth relative -3 dB points (degree centigrades)

BEAMWIDTH

Vertical Beamwidth

Since the concentration of radiation is proportional to L/l, the vertical beamwidth decreases as the gain increases. The vertical beamwidth can be estimated if the length of the antenna is known:

V3 = 15300/(F x l)

V3 = Vertical beamwidth relative – 3 dB points (degrees centigrades)

F= Frequency (MHz)

l= Antenna length (meter)

[firstmaxim]

Nice simple formula. But we need to remove centigrade, and just put plain degree when plugging in the values of beam-angles.

Regards.