Beam shape loss for Gaussian antenna pattern
calculates the beam shape loss
lb = beamloss
lb for a radar that scans over one angular dimension (1-D). The
beamloss function assumes the antenna has a Gaussian pattern and
densely samples the angular domain. For the angular domain to be densely sampled, beam
dwells must be spaced by less than 0.71 of the one-way half-power beamwidth.
You can use
lb as an accurate approximation of loss for antenna
patterns other than Gaussian patterns.
Calculate the power-aperture product for a search radar performing a two-dimensional search by using the
radareqsearchpap function. Include beam shape loss by using the
Specify a search volume of
0.2 steradians and a search time of
4 seconds. The radar requires a signal-to-noise ratio (SNR) of
20 decibels to detect a 1 square meter radar cross-section (RCS) target at a range of
100000 meters. By default, the system noise temperature is 290 kelvin.
omega = 0.2*pi; tsearch = 4; snr = 20; range = 100000;
Calculate the power-aperture product, including the beam shape loss. Assume the rest of the losses for the system are 0 decibels.
lb = beamloss; pap = radareqsearchpap(range,snr,omega,tsearch,'Loss',lb)
pap = 105.0012
is2d— Scanning in two angular dimensions
Scanning in two angular dimensions, specified as numeric or logical
false). When you do not specify
function assumes the radar scans in one angular dimension.
lb— Beam shape loss
Beam shape loss in decibels, returned as a scalar.
Incorporate beam shape loss into the standard
form of the radar range equation implemented by the
functions to account for the use of peak gain instead of effective gain. The effective gain
results from the two-way pattern of the scanning antenna modulating the received train of
The power equation for 1-D beam shape loss for an antenna with a Gaussian pattern, Lp1, is
The power equation for 2-D beam shape loss for an antenna with a Gaussian pattern, Lp2, is
In decibels, the 1-D beam shape loss is 1.2338 and the 2-D beam shape loss is 2.4677.
You can use beam shape loss for an antenna with a Gaussian pattern as an accurate approximation of loss for antennas with other patterns.
 Barton, David Knox. "Beamshape Loss for Different Patterns." In Radar Equations for Modern Radar, 148–149. Artech House Radar Series. Boston, Mass: Artech House, 2013.