Page 216 - Antennas for Base Stations in Wireless Communications

Antenna Issues and Technologies for Enhancing System Capacity 189

120
Without parasitic conductors
110

100
HPBW [degree] 90

80

70 D = 0.013λ
D = 0.067λ
60
0.0 0.2 0.4 0.6
Spacing [λ]
Figure 5.13 The change in HPBW with parasitic conductors

<Calculated pattern> Without conductors, With conductors
<Measured pattern> Without conductors, With conductors
φ = 0 [degree]
0
330 30
−10 300 60
−20
Normalized directivity [db] −30 270 90

−40

−30

−20
−10 240 120

0 210 150
180
Figure 5.14 The change in radiation patterns with parasitic conductors

aperture of a 90° HPBW is only about 0.3l, whereas the aperture of the
antenna shown in Figure 5.6c is 0.267l, and the radius of the metal
conductors is 0.13l. In addition, the antenna with the metal conductors
achieves a 10 dB lower back radiation than that of the antenna without
the metal conductors.