User's Manual

Axell D-SBR 3709S Repeater
PRODUCT DESCRIPTION AND USER’S MANUAL
© Axell Wireless Ltd Doc PN 00038UMCD Rev. 1.6 V
Antenna Installation
Installation of an antenna must comply with the FCC RF exposure requirements. The
antenna used for this transmitter must be mounted on permanent structures.
The FCC regulation mandates that the EIRP of type B signal boosters should not exceed
5W.
Therefore the max antenna gain allowed for this type of signal booster should be limited
to the values given by equation (1) for the service antenna and equation (2) for the
donor antenna
Equation (1) - Max SERVICE antenna gain
Max SERVICE antenna gain (dBi) = 37 – (33dBi - # of antennas in dBi – cable losses in dBi).
For example:
No. of Antennas Cable Losses Max Allowed Antenna Gain
4 3 37 - (33-6-3) = 13dBi
1 3 37- (33-3) = 7dBi
10 3 37- (33-10-3) = 17dBi
Equation (2) - Max DONOR antenna gain
Max antenna gain (dBi) = 37 – (27dBi - cable losses in dBi).
Compliance with FCC deployment rule regarding the radiation of noise
Good engineering practice must be used in regard to the signal booster’s noise
radiation. Thus, the gain of the signal booster should be set so that the EIRP of the
output noise from the signal booster should not exceed the level of -43 dBm in 10 kHz
measurement bandwidth.
In the event that the noise level measured exceeds the aforementioned value, the signal
booster gain should be decreased accordingly.
In general, the ERP of noise on a spectrum more than 1 MHz outside of the pass band
should not exceed -70 dBm in a 10 kHz measurement bandwidth.
The 3709 signal booster has a noise level of -50 dBm in 10 kHz measurement at 1 MHz
spectrum outside the passband of the signal booster and an in-band noise level at
around -34 dBm in a 10 kHz bandwidth. Therefore, the noise at the antenna input port
should be calculated based on equation (3).
Equation (3) - Input Noise to SERVICE antenna
Input Noise to service antenna:
-43 dBm + Service Antenna gain – Antenna splitter losses in dBi – cable loss in dB
Example:
Signal booster connected to 10 service antennas with a 100m long ½ inch cable.
• Losses of such a cable with the connectors = ~ 11dB
• Gain = ~ 2 dBi
Assuming 10 service antennas: antenna splitter losses = 11 dB
Based on equation (3) Input antenna noise (to the antenna) =
-51.1+2-11-11=-71.1 dBm
The inband input noise to the antenna should be -32+2 -11-11= -52 dbm