Rotate Antennas and Arrays
To rotate antenna elements in Antenna Toolbox™, use the Tilt
and TiltAxis
properties. The Tilt
property specifies the angles of rotation of
the antenna in degrees. The TiltAxis
property specifies the one or
more axes of rotation (X, Y, Z)
of the antenna.
Rotate Single Antenna Element
Create a patch antenna. By default, this antenna is on the X-Y plane.
patch = patchMicrostrip; show(patch)
To make the antenna lie on the Y-Z plane, rotate it by 90 degrees about the Y-axis. The rotation follows the standard right-hand rule.
patch.TiltAxis ="Y";
patch.Tilt = 90;
show(patch)
The patch lies behind the ground plane and is not visible. To make the patch
visible change the TiltAxis
property to [0 -1
0]
. The Tilt
property is still
90
, but the axis of rotation is now the Y-axis. The negative
number in the TiltAxis
vector determines the direction of
rotation about the Y-axis as per the right-hand rule.
patch.TiltAxis = [0 -1 0]; show(patch)
Rotate Single Antenna Element About Multiple Axes
Create a dipole antenna. Change the direction of rotation of the antenna with two
rotations simultaneously. Rotate the antenna by 90
degrees about
the axis specified by [0 1 0]
and rotate it by
90
degree about the axis specified by [0 1
1]
.
d = dipole(Tilt=[90 90], TiltAxis=[0 1 0; 0 1 1])
dipole with properties: Length: 2 Width: 0.1000 FeedOffset: 0 Tilt: [90 90] TiltAxis: [2x3 double]
show(d)
Rotate Dipole-Backed Reflector
The Tilt
and TiltAxis
properties are
available for dipole and reflector elements. Use these properties if you want to
model an antenna parallel or perpendicular to the ground plane.
Create a reflector element. By default, the dipole is parallel to the reflector element.
r = reflector; show(r)
The dipole is the exciter element of the reflector. View its properties.
r.Exciter;
dipole with properties: Length: 0.1500 Width: 0.0050 FeedOffset: 0 Tilt: 90 TiltAxis: [0 1 0]
Based on the Tilt
and TiltAxis
properties
the dipole element is rotated by 90 degrees about the y-axis and is parallel to the
X-Y plane. To make the dipole perpendicular to the X-Y plane, change the
Tilt
property of the dipole to 0
degrees.
r.Exciter.Tilt = 0; show(r)
Rotating the reflector element rotates the entire structure by the specified
angle. To rotate the complete antenna, use the Tilt
property of
the reflector object. For example, rotate the reflector by 90 degrees about the
X-axis. According to the right-hand rule, the reflector now lies in the X-Z plane
with the dipole.
r = reflector; r.Tilt = 90; show(r)
Rotate Antenna Array
Create an array of Archimedean spirals with the whole array rotated at 30 degrees about the X-axis and Y-axis. First create one spiral antenna.
s = spiralArchimedean;
l = linearArray(Element=s, ElementSpacing=0.1,...
NumElements=3, Tilt=30, TiltAxis=[1 1 0]);
show(l)