RESP = step(H,FREQ,ANG) returns
the antenna's voltage response RESP at
operating frequencies specified in FREQ and directions
specified in ANG. The form of RESP depends
upon whether the antenna element supports polarization as determined
by the SpecifyPolarizationPattern property. If SpecifyPolarizationPattern is
set to false, RESP is an M-by-L matrix
containing the antenna response at the M angles
specified in ANG and at theL frequencies
specified in FREQ. If SpecifyPolarizationPattern
is set to true, RESP is a MATLAB^{®}struct containing
two fields, RESP.H and RESP.V,
representing the antenna's response in horizontal and vertical polarization,
respectively. Each field is an M-by-L matrix
containing the antenna response at the M angles
specified in ANG and at theL frequencies
specified in FREQ.

Note:
The object performs an initialization the first time the step method
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

H

Antenna element object.

FREQ

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

ANG

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

RESP

Voltage response of antenna element. The output depends on whether
the antenna element supports polarization or not.

If the antenna element does not support polarization, RESP is
an M-by-L matrix. In this matrix, M represents
the number of angles specified in ANG while L represents
the number of frequencies specified in FREQ.

If the antenna element supports polarization, RESP is
a MATLAB struct with fields RESP.H and RESP.V containing
responses for the horizontal and vertical polarization components
of the antenna radiation pattern. RESP.H and RESP.V are M-by-L matrices.
In these matrices, M represents the number of angles
specified in ANG while L represents
the number of frequencies specified in FREQ.

Examples

Construct a user defined antenna with an omnidirectional response
in azimuth and a cosine pattern in elevation. The antenna operates
at 1 GHz. Find the response of the antenna at the boresight.

The total response of a custom antenna element is a combination
of its frequency response and spatial response. phased.CustomAntennaElement calculates
both responses using nearest neighbor interpolation, and then multiplies
the responses to form the total response.