System object: phased.ShortDipoleAntennaElement
Package: phased

Output response of antenna element





Starting in R2016b, instead of using the step method to perform the operation defined by the System object™, you can call the object with arguments, as if it were a function. For example, y = step(obj,x) and y = obj(x) perform equivalent operations.

RESP = step(H,FREQ,ANG) returns the antenna’s voltage response, RESP, at the operating frequencies specified in FREQ and in the directions specified in ANG. For the short-dipole antenna element object, RESP is a MATLAB® struct containing two fields, RESP.H and RESP.V, representing the horizontal and vertical polarization components of the antenna's response. Each field is an M-by-L matrix containing the antenna response at the M angles specified in ANG and at the L frequencies specified in FREQ.


The object performs an initialization the first time the object is executed. This initialization locks nontunable properties and input specifications, such as dimensions, complexity, and data type of the input data. If you change a nontunable property or an input specification, the System object issues an error. To change nontunable properties or inputs, you must first call the release method to unlock the object.

Input Arguments


Antenna element object.


Operating frequencies of antenna in hertz. FREQ is a row vector of length L.


Directions in degrees. ANG can be either a 2-by-M matrix or a row vector of length M.

If ANG is a 2-by-M matrix, each column of the matrix specifies the direction in the form [azimuth; elevation]. The azimuth angle must be between –180 and 180 degrees, inclusive. The elevation angle must be between –90 and 90 degrees, inclusive.

If ANG is a row vector of length M, each element specifies a direction’s azimuth angle. In this case, the corresponding elevation angle is assumed to be 0.

Output Arguments


Voltage response of antenna element returned as a MATLAB struct with fields RESP.H and RESP.V. Both RESP.H and RESP.V contain responses for the horizontal and vertical polarization components of the antenna radiation pattern. Both RESP.H and RESP.V are M-by-L matrices. In these matrices, M represents the number of angles specified in ANG, and L represents the number of frequencies specified in FREQ.


expand all

Find the response of a short-dipole antenna element at boresight, (0°,0°), and off boresight, (30°,0°). The antenna operates at 256 MHz.

antenna = phased.ShortDipoleAntennaElement(...
    'FrequencyRange',[100 900]*1e6,'AxisDirection','Y');
ang = [0 30;0 0];
fc = 250e6;
resp = antenna(fc,ang)
resp = struct with fields:
    H: [2x1 double]
    V: [2x1 double]

Horizontal response.


Vertical response.



The total response of a short-dipole antenna element is a combination of its frequency response and spatial response. This System object calculates both responses using nearest neighbor interpolation and then multiplies the responses to form the total response.