Page 24 - Antennas for Base Stations in Wireless Communications

Introduction xxiii

antenna designs with simulations and measurements, this chapter
demonstrates that this new antenna structure is highly suitable for
developing base station antennas for both 2G and 3G mobile wireless
communication systems.

Chapter 4
Chapter 4 introduces advanced antenna technologies for the fixed GSM-
base stations in mobile wireless communication systems. It starts by
describing the benefits obtained from advanced antennas in GSM base
stations. Then we briefly review advanced antenna technologies, includ-
ing antenna beamtilt, higher order sectorization, fixed multibeam array
antennas, steered beam array antennas, receiver-diversity, coverage
concepts, three-sector omnidirectional patterns, modular high-gain anten-
nas, amplifier integrated sector antennas, and amplifier integrated multi-
beam array antennas. After that, the case studies related to the antenna
technologies just mentioned are included. This chapter highlights many
practical engineering issues from a systems point of view.

Chapter 5
Chapter 5 first presents the special aspects of mobile communication
systems operating in Japan, which occupy so many frequency bands
that antenna arrays with multiple operating frequency bands or multi-
ple antenna arrays operating in different frequency bands are required.
Several designs are available to meet such practical requirements. The
TDMA-based PDC and W-CDMA systems are briefly introduced for
understanding the requirements of base stations. Then the practical
design considerations for antenna design are highlighted from a system
point of view. In 3G networks, one of the most important considerations
in antenna configuration is increasing the number of subscribers or
system capacity. Ways to select the antenna structures and design the
actual antennas for increasing system capacity are suggested. The tech-
nique to control vertical radiation patterns is elaborated from an engi-
neering point of view.
This chapter looks at five typical antenna designs, which have been
applied in practical wireless access systems. First, slim antennas with
small widths, which may be single-band or multiple-band antennas, are
preferred due to limited space for, and the high cost of, antenna installa-
tions in Japan. A detailed case study is presented. Second, this chapter
demonstrates that the horizontal radiation pattern of an antenna can be
controlled by adding metallic conductors in the vicinity of the existing
base station antenna. Third, an omnidirectional vertical array antenna of
width 0.09l for spot cells is described. Fourth, booster antennas that have
the high FB ratio and low sidelobe levels needed for the realization of a