Compute half-power beamwidth from aperture length
Estimate the half-power beamwidths of side-looking airborne radars, each operating at wavelengths of 1, 2, and 3 centimeters. The radars have antenna aperture sizes of 2 and 3 meters in the azimuth direction.
lambda = [1,2,3]*1e-2; daz = [2,3]; hpbw = ap2beamwidth(daz,lambda)
hpbw = 2×3 0.2865 0.5730 0.8594 0.1910 0.3820 0.5730
Estimate the half-power beamwidth of a radar operating at a wavelength of 2 cm. The radar has an antenna aperture dimension of 2 m in the azimuth direction. Use an azimuth broadening factor of 1.5.
lambda = 2e-2; daz = 2; azbf = 1.5; hpbw = ap2beamwidth(daz,lambda,azbf)
hpbw = 0.8594
d— Length of unweighted antenna
Length of unweighted antenna, specified as a positive scalar or length-J vector of positive values. Units are in meters.
lambda— Radar wavelength
Radar wavelength, specified as a positive real scalar or a length-K vector of real values.
azb— Azimuth impulse broadening factor
1.0(default) | positive real scalar
Azimuth impulse broadening factor, specified as a positive real scalar. Broadening
is due to data weighting or windowing for side lobe control. The quantity is the actual
–3 dB main lobe width with respect to the nominal width. Typical window functions such
hann exhibit azimuth impulse
broadening factors in the range of 1 to 1.5.
rlhpbw— Half-power one-way beamwidth
The half-power beamwidth (in degrees) for a rectangular aperture is 180λ/πd where λ is the radar wavelength and d is the aperture length. The azimuth broadening factor b multiplies the beamwidth to produce a half-power beamwidth of 180bλ/πd.