Antenna 3dB Beam width is the angle between the half-power of an antenna pattern or beam over which the relative power is at or above 50% of the peak power. Antenna beam width is also known as the half-power.
λ = Wavelength D = Diameter λ = 0.3 / frequency
An antenna has a diameter of 2m and frequency 16GHz. Calculate the 3 DB beamwidth for the antenna.
Diameter = 2m, Frequency = 16GHz
3 dB Beamwidth
Let us first calculate the value of λ, Substitute the values in the λ formula, λ = 0.3 / frequency λ = 0.3 / 16 λ = 0.01875
Now, substitute the values in the beamwidth formula,
|Beamwidth||= ( 70 * 0.01875 ) / 2|
|= 1.3125 / 2 degrees|
|= 0.656 degrees|
Learn how to calculate the 3dB antenna beamwidth and cutoff frequency in this tutorial, given with the definition, formula and example.