Create a helix antenna that has a 28 mm radius, a 1.2 mm width, and 4 turns. Plot the directivity of the antenna at 1.8 GHz.

hx = helix('Radius',28e-3,'Width',1.2e-3,'Turns',4);
H = pattern(hx, 1.8e9,0,0:1:360);
P = polarpattern(H);

Create a dipole antenna and calculate its directivity at 270 MHz.

d = dipole;
D = pattern(d,270e6,0,0:1:360);

Replace the existing polar plot of the helix antenna with the directivity of the dipole using the animate method.

animate(P,D);

Create a default dipole antenna and plot the polar pattern of its directivity at 1 GHz.

d = dipole;
D = pattern(d,75e6,0,0:1:360);
P = polarpattern(D);

Create a default cavity antenna. Calculate the directivity of the antenna and write the data to cavity.pln using the msiwrite function.

c = cavity;
msiwrite(c,2.8e9,'cavity','Name','Cavity Antenna Specifications');

Read the cavity specifications file into Horizontal, Vertical and Optional structures using the msiread function.

[Horizontal,Vertical,optional]= msiread('cavity.pln')

Horizontal = struct with fields:
    PhysicalQuantity: 'Gain'
           Magnitude: [360x1 double]
               Units: 'dBi'
             Azimuth: [360x1 double]
           Elevation: 0
           Frequency: 2.8000e+09
               Slice: 'Elevation'

Vertical = struct with fields:
    PhysicalQuantity: 'Gain'
           Magnitude: [360x1 double]
               Units: 'dBi'
             Azimuth: 0
           Elevation: [360x1 double]
           Frequency: 2.8000e+09
               Slice: 'Azimuth'

optional = struct with fields:
         name: 'Cavity Antenna Specifications'
    frequency: 2.8000e+09
         gain: [1x1 struct]

Replace data from the dipole antenna with data from cavity antenna.

animate(P,Horizontal.Azimuth,Horizontal.Magnitude);