Crossed-dipole antenna element
The phased.CrossedDipoleAntennaElement System object™ models a crossed-dipole antenna element. A crossed-dipole antenna is often used for generating circularly polarized fields. A crossed-dipole antenna is formed from two orthogonal short-dipole antennas, one along y-axis and the other along the z-axis in the antenna's local coordinate system. This antenna object generates right-handed circularly polarized fields along the x-axis (defined by 0° azimuth and 0° elevation angles).
To compute the response of the antenna element for specified directions:
h = phased.CrossedDipoleAntennaElement creates the system object, h, to model a crossed-dipole antenna element.
h = phased.CrossedDipoleAntennaElement(Name,Value) creates the system object, h, with each specified property Name set to the specified Value. You can specify additional name-value pair arguments in any order as (Name1,Value1,...,NameN,ValueN).
Antenna operating frequency range
Antenna operating frequency range specified as a 1-by-2 row vector in the form of [LowerBound HigherBound]. This defines the frequency range over which the antenna has a response. The antenna element has no response outside the specified frequency range.
Default: [0 1e20]
|clone||Create crossed-dipole antenna object with same property values|
|directivity||Directivity of crossed-dipole antenna element|
|getNumInputs||Number of expected inputs to step method|
|getNumOutputs||Number of outputs from step method|
|isLocked||Locked status for input attributes and nontunable properties|
|plotResponse||Plot response pattern of antenna|
|release||Allow property value and input characteristics changes|
|step||Output response of antenna element|
Examine the response patterns of a crossed-dipole antenna used in an L-band radar with a frequency range between 1-2 GHz.
First, set up the radar parameters, and obtain the vertical and horizontal polarization responses at five different directions: elevation angles -30, -15, 0, 15 and 30 degrees, all at 0 degrees azimuth angle. The responses are computed at an operating frequency of 1.5 GHz.
scd = phased.CrossedDipoleAntennaElement(... 'FrequencyRange',[1,2]*1e9); fc = 1.5e9; resp = step(scd,fc,[0,0,0,0,0;-30,-15,0,15,30]); [resp.V, resp.H]
ans = -1.0607 + 0.0000i 0.0000 - 1.2247i -1.1830 + 0.0000i 0.0000 - 1.2247i -1.2247 + 0.0000i 0.0000 - 1.2247i -1.1830 + 0.0000i 0.0000 - 1.2247i -1.0607 + 0.0000i 0.0000 - 1.2247i
Next, draw a 3-D plot of the combined polarization response.
The total response of a crossed-dipole antenna element is a combination of its frequency response and spatial response. phased.CrossedDipoleAntennaElement calculates both responses using nearest neighbor interpolation, and then multiplies the responses to form the total response.