Wirnet iBTS
Document title : Installation and
Maintenance Manual
Version : 2.0
Author : SNI
Date : 04/12/2018
Classification
This document is the strict property of Kerlink and shall not be either copied nor sent without express
written authorization of Kerlink
Internal Use
Kerlink m2m technologies reserved rights
Confidential
Kerlink – 1 rue Jacqueline Auriol – 35235 THORIGNÉ-FOUILLARD
Page 62 / 221
Strict confidential
Figure 32: Front-end 4 modules full-duplex board block diagram
The front-end board integrates two TX and two Rx paths (RF1 path and RF2 path). Each TX
and RX path is connected to one SMB antenna port.
The two TX paths are similar and are detailed hereafter:
-
The TX signal(s), coming from the 4 LoRa LOC board(s), is injected in a pre-amplifier
filter via a combiner (splitter). The amplifier has very high linearity to minimize
intermodulation.
-
The signals are then injected into a RF band-pass filter. The main goal of this RF filter
is to reject the harmonics and shape the noise outside the band pass, especially in
the WAN bands.
-
The TX signal is amplified by a 2W power amplifier. This amplifier has an excellent
linearity to minimize intermodulation.
The front-end is then able to transmit 4 RF signals simultaneously per RF antenna port.
The receive paths are also similar.
The Rx path includes:
-
A first LNA with a very low noise figure, in order to not degrade the sensitivity of the
receiver.
RF1 path
