User Manual

Axell Wireless Limited
Technical Literature
UHF Dual Band Line Amplifier
Document Number 55-227901HBK
Issue No. 4
Date 23/06/2014
Page 5 of 30
Radiating Antenna Installation
CAUTION! This Equipment is designed as an in-line Radiating Cable booster
and must not be used as a Class B Off-Air repeater.
Installation of a radiating cable antenna must comply with the FCC RF exposure requirements. The
radiating cable used for this transmitter must be mounted on permanent structures.
The FCC regulations mandate that the EIRP of type B signal boosters should not exceed 5W.
The radiating cable associated with In-Line Boosters has a high attenuation of coupling and as such a
negative gain. The Line Amplifier has a maximum amplifier P1dB of +26.5dBm (0.44w), the radiating
cable is typically -50dB radiating loss and therefore the ERP will always be below the 5W limit.
Equation (1) - Max SERVICE antenna gain
Not Applicable – Radiating cable fed equipment.
Equation (2) - Max DONOR antenna gain
Not Applicable – Radiating cable fed equipment
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 WMATA Line Amplifier (55-227901) signal booster has a noise level of below -90 dBm in 10 kHz
measurement at 1 MHz spectrum outside the passband of the signal booster and an in-band noise
level of -60 dBm (worst case) in a 10 kHz bandwidth.
Conclusion:
Good engineering practice requires that in general when the out of band noise measured at the
service antenna input is more than -70 dBm per 10 kHz measurement bandwidth, an external band
pass filter should be added to attenuate the out of band noise level. However, in this application
using radiating cables, No further filtering will be required because of the cable coupling attenuation.