Datasheet

8/27/2013
8
Impedance
Choosing the right cable, 50ohm or 75ohm
Loss per 100’
850mhz = 8.30dB
1900mhz = 13.35dB
Figure at 10dB/100’
RG6
RG11 low loss
Loss per 100’
850mhz = 4.75dB
1900mhz = 7.50dB
Figure at 6db/100’
LMR400 low loss
Loss per 100’
850mhz = 4.55dB
1900mhz = 7.00dB
Figure at 5.5dB/100’
F connector
75 ohm
F connector
75 ohm
N connector
50 ohm
Oscillation & Overload
• Oscillation – Occurs when inside antenna and outside antenna “talk” to each
other, causing an RF loop or feedback. Solution is to increase separation of the
antennas, or turn down gain on the amplifier. Increasing isolation is the key and
can be achieved mechanically in some cases.
• Overload – Caused by close proximity to a cell tower. The offending tower
may be on another network. If working with a directional outside antenna, re-
orienting the antenna and or reducing gain may solve the issue.