Boomer-III User Manual & Integrator’s Guide_________________________________________________Installation
BM310012WT04
39
Copyright Wavenet Technology © October 2003
Selecting & Positioning the Antenna
Use this information to assist you in selecting the appropriate antenna
to incorporate into your product package. For specific detailed
information, Wavenet recommends that you use the expertise of an
antenna design engineer to solve individual application concerns. Also
always consult the appropriate technical representative of the target
network operator prior to selecting and / or designing the antenna, so
that it will pass network certification requirements.
Antenna Safety
The design of the integrated product must be such that the location
used and other particulars of the antenna comply with the appropriate
standards of the country in which the host/terminal is to be used.
The integrator should refer to the statement of Compliance on page 8 of
this manual and Regulatory Requirements section on pages 19-23 for
country requirements.
Mobile and Portable Devices
In the environment where portable devices are in use, many variables
exist that can affect the transmission path. In this case, it would be
preferable to use a vertically polarized, omni directional antenna.
Antennas for portable devices include the following designs:
Internal antenna (invisible or pull-up)
An internal antenna must provide a gain sufficient to meet network
specifications. Cable routing from the modem to the antenna needs to
avoid RF sensitive circuits and high level, high-speed clock circuits.
Consider:
The location of the antenna to avoid RFI to a computing device.
Good shielding to the display and other RF-sensitive
components
The most efficient method of cable routing
Otherwise, antenna gain can be offset by cable loss. A typical coaxial
cable is very thin, such as RG178B used in portable devices, and cable
loss can be 1dB or more per metre. Some coaxial cable manufacturers
market relatively thin double braid coaxial cables. These cables show
much better isolation than single braid cables, typically by 30 to 40dB.
These double braid cables reduce radiation and RF pick-up when
routed inside a portable device.
External antenna, removable and directly connected to the device
You can design a portable device that can use an off-the-shelf, plug-in
antenna, such as a ¼ wave monopole or ½ wave dipole antenna.
Typical gain of these omni directional antennas is 0dBi and 2.14dBi,
respectively.
