Page 148 - Antennas for Base Stations in Wireless Communications

Antennas for Mobile Communications: CDMA, GSM, and WCDMA 121

0 0
330 0 30 330 0 30
−10 −10
300 −20 60 300 −20 60
−30 −30
−40 −40
270 90 270 90

240 120 240 120

210 150 210 150
180 180
(a) (b)
0
330 0 30
−10
300 −20 60
−30
co-pol (measured)
−40 x-pol (measured)
270 90
co-pol (simulated)
x-pol (simulated)
240 120

210 150
180
(c)
Figure 3.19 Elevation plane radiation patterns (f = 0°) of the monopolar antenna at
(a) 1.545 GHz, (b) 2.145 GHz, and (c) 2.745 GHz

To summarize, the antenna performance determined by the measure-
ment and simulation are in close agreement.

3.2.4.3 Summary A broadband monopolar antenna was designed and
implemented successfully. Measured results demonstrate that it has a
wide impedance bandwidth (SWR < 1.5) from 1.48 to 2.81 GHz, which
is equal to 62%. Within this frequency band, it has a nearly omnidirec-
tional radiation pattern in the azimuth plane and off-broadside radia-
tion pattern in the elevation plane. Moreover, it has other advantages
such as low profile, small lateral size, and moderate peak gain. This
antenna is suitable for an indoor base station network that serves sev-
eral wireless communication systems, including PCS, UMTS, Bluetooth,
and WLAN, in an integration manner.