System object: phased.ULA
Plot ULA array directivity or pattern versus azimuth
PAT = patternAzimuth(___)
The integration used when computing array directivity has a minimum sampling grid of 0.1 degrees. If an array pattern has a beamwidth smaller than this, the directivity value will be inaccurate.
in addition, plots the 2-D array directivity pattern versus azimuth (in dBi) for the array
sArray at the elevation angle specified by
EL is a vector, multiple overlaid plots are created.
the array pattern.
PAT = patternAzimuth(___)
PAT is a matrix whose entries
represent the pattern at corresponding sampling points specified by
'Azimuth' parameter and the
sArray — Uniform linear array
Uniform linear array, specified as a
phased.ULA System object.
Specify optional pairs of arguments as
the argument name and
Value is the corresponding value.
Name-value arguments must appear after other arguments, but the order of the
pairs does not matter.
Before R2021a, use commas to separate each name and value, and enclose
Name in quotes.
Parent — Handle to axis
Handle to the axes along which the array geometry is displayed specified as a scalar.
Plot Azimuth Pattern of ULA
Create a 7-element ULA of short-dipole antenna elements spaced 10 cm apart. Plot an azimuth cut of directivity at 0 and 10 degrees elevation. Assume the operating frequency is 500 MHz.
fc = 500e6; sCDant = phased.ShortDipoleAntennaElement('FrequencyRange',[100,900]*1e6); sULA = phased.ULA('NumElements',7,'ElementSpacing',0.1,'Element',sCDant); patternAzimuth(sULA,fc,[0 30])
You can plot a smaller range of azimuth angles by setting the
Directivity describes the directionality of the radiation pattern of a sensor element or array of sensor elements.
Higher directivity is desired when you want to transmit more radiation in a specific direction. Directivity is the ratio of the transmitted radiant intensity in a specified direction to the radiant intensity transmitted by an isotropic radiator with the same total transmitted power
where Urad(θ,φ) is the radiant intensity of a transmitter in the direction (θ,φ) and Ptotal is the total power transmitted by an isotropic radiator. For a receiving element or array, directivity measures the sensitivity toward radiation arriving from a specific direction. The principle of reciprocity shows that the directivity of an element or array used for reception equals the directivity of the same element or array used for transmission. When converted to decibels, the directivity is denoted as dBi. For information on directivity, read the notes on Element Directivity and Array Directivity.