Computes aperture length of unweighted antenna from beamwidth
Compute the aperture length of a radar from its half-power beamwidth. The radar is designed to operate at a wavelength of 2 centimeters. The radar has a half-power beamwidth of one degree. Use the default azimuth broadening factor.
lambda = 2e-2; bw = 1; aplen = beamwidth2ap(bw,lambda)
aplen = 1.1459
Estimate the aperture lengths of two side-looking airborne radars operating at wavelengths of 1, 2, and 3 centimeters. The radars have beamwidths of 2 and 3 degrees in the azimuth dimension.
lambda = [1,2,3]*1e-2; bw = [2,3]; aplen = beamwidth2ap(bw,lambda)
aplen = 2×3 0.2865 0.5730 0.8594 0.1910 0.3820 0.5730
Compute the aperture length of a radar operating at a wavelength of 2 centimeters. The radar has a beamwidth of 2 deg in the azimuth direction. Use an azimuth broadening factor of 1.5.
lambda = 2e-2; bw = 2; azbf = 1.5; ap = beamwidth2ap(bw,lambda,azbf)
ap = 0.8594
Estimate the aperture length of each side of a rectangular aperture antenna. The antenna operates at a wavelength of 10 cm. In this case, the input beamwidth array
bw describes the two beamwidths of the same antenna. The radar has a half-power beamwidth of 1 degree along one dimension and a half-power beamwidth of 2 degrees along the other.
bw = [1,2]; lambda = 0.01; ap = beamwidth2ap(bw,lambda)
ap = 2×1 0.5730 0.2865
hpbw— Half-power one-way beamwidth
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 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 as
hann exhibit azimuth impulse
broadening factors in the range of 1 to 1.5.
d— Length of unweighted antenna
Length of unweighted antenna, returned as a positive scalar or length-J vector of positive values. Units are in meters.
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.