a Matlab package for phased array beam shape inspection

36 A FIGURES TO CHAPTERS 2–7
D=0.1; θ = 60, θ = 60
0 g
90 1.5
120
60
1
150
30
0.5
180 0
Directivity
1.16
1.14
1.12
1.1
1.08
210
330
1.06
1.04
240
270
300
1.02
0 20 40 60 80 100
elevation polar angle
(a)
(b)
150
D=0.4; θ =60, θ = 60
0 g
90
2.5
120
60
2
1.5
1
30
2.5
2.4
2.3
2.2
0.5
180 0
Directivity
2.1
2
1.9
210
330
1.8
1.7
240
270
300
1.6
0 20 40 60 80 100
elevation polar angle
(c)
(d)
Figure 2: Gain pattern and directivity of an vertical array of two isotropic elements.
Panels (a) and (b) are for element separation d = 0.1λ, panels (c) and (d) are
for d = 0.4λ. The beam steering in panels (a) and (c) has been to 60 ◦ from
boresight (horizontal beam). The 3D gain pattern is obtained from the curves
shown by rotating them around the vertical axis, which is also the direction
of the array axis. The polar plots are labeled by the beam elevation angle,
and the gain is in absolute units. Both of these arrays are dense (D < 0.5λ),
so there are no grating lobes apart the main lobe, but there nevertheless is a
rather well-developed ordinary side lobe in (c).