a Matlab package for phased array beam shape inspection

38 A FIGURES TO CHAPTERS 2–7
D=1.4; θ 0
= 0, θ g
= −46, 0, 46
D=1.4; θ 0
= 16, θ g
= −26, 16, 82
150
120
90
2
1.5
1
0.5
60
30
150
120
90
2.5
2
1.5
1
0.5
60
30
180 0
180 0
210
330
210
330
240
270
300
240
270
300
(a)
(b)
D=1.4; θ 0
= 20, θ g
= −22, 20
90
2.5
120
60
2
1.5
150
1
30
0.5
180 0
Directivity
2.15
2.1
2.05
2
1.95
210
330
1.9
240
270
300
1.85
0 20 40 60 80 100
polar Elevation angle
(c)
(d)
Figure 4: Gain pattern and directivity of an vertical array of two isotropic elements.
Element separation is d = 1.4λ. Beam steering is to 0 ◦ (horizontal) in panel (a),
to elevation 16 ◦ in (b) and to 20 ◦ in (c). In (a), all the three lobes are grating
lobes, in (b), there are three grating lobes, and in (c), only two grating lobes.
As function of the steering angle, the directivity oscillates around the value 2,
the absolute maximum value 2.14 is achieved with the steering angle 20.9 ◦ .