Wavenet Technology Pty Ltd. BM2900D Manuel D’Utilisation

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Boomer II User Manual & Integrator’s Guide _________________________________________________Installation 
 
BM210012WT37 
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Copyright Wavenet Technology © November 2003 
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. 
Cabling demands the same consideration as an internal antenna 
application. In a typical laptop application, the antenna must be placed 
as far as possible from a display to avoid deflection. This usually 
causes a deep null in radiation patterns. 
External, remote antenna  
For remote antenna application use the same design approach as 
internal designs, including the RF cable routing of the external 
connector. You can choose an off-the-shelf mobile antenna of omni 
directional ½ wave length.  
A double braid coaxial cable such as RG223 from the device to the 
antenna is recommended if the cable length is more than a metre. The 
difference in cable loss between low cost RG58 and the more 
expensive RG223 is approximately 4.5dB per 30 metres. If the cable 
must be routed through noisy EMI/RFI environments, a double braid 
cable such as RG223 can reduce radiation and pick-up by 30 to 40dB. 
Fixed Devices 
Fixed data device applications use the same design recommendations 
as a portable device with a remote antenna. 
As for the RF connector of an external antenna, whether it is a plug-in 
type or a remote type, the most economical and practical choice is a 
TNC threaded connector. TNC has a good frequency response to 
7GHz, and leakage is low. A mini UHF threaded connector provides 
adequate performance and is an economical choice. If the size of the 
TNC and mini UHF connectors becomes critical, consider an SMA 
threaded connector or an SMB snap fit connector. (The SMB connector 
does not accept an RG58 or RG223 cable). 
Selecting an Antenna 
The requirements for the antenna used with the Boomer II OEM 
Modem are: 
Antenna Gain: 
Up to a 12dBd maximum gain antenna 
can be used using the module FCC 
approvals alone without separate 
equipment approval for the host/terminal.  
with separation distances as per the