User Manual

MBF, Multi Band Repeater

PRODUCT DESCRIPTION AND USER'S MANUAL

1.2.3.1 Donor Unit

There are two types of donor units – single donor (SD) and double donor (DD).

A single donor (SD) unit has one input connector. The input signal from the BTS is split in two within the

repeater unit. In the opposite direction – in the uplink – the signals are combined within the repeater before

being sent to the BTS.

A double donor (DD) unit has dual inputs. This can be used in combination with a BTS that uses air

combining, and hence has a separate antenna for each TRU. A double donor unit can alternatively handle two

signals from two separate BTS.

1.2.3.2 Remote Unit

There are two types of remote units – internal combining (IR) and external combining (ER).

In an internal combining (IR) remote unit output from the power amplifiers in the downlink is combined and

filtered before being passed on to the server antenna. In the uplink the signal is separated within the remote

unit.

An external combining remote (ER) unit has two server antenna ports and the signal is combined in the air.

Since the ER model needs no combiner the output signal and gain is 3dB higher than in the IR model.

1.2.4 Band Shifting Repeaters

Band shifting repeaters are based on the same concept as frequency translating repeaters described above.

In contrast to a frequency translating repeater, which uses another frequency within the same band for the

link, a band shifting repeater uses another band. For instance can a repeater operating on the 900MHz band

use the 1800MHz band for the link and vice versa. Other combinations are also possible.

Donor Cell

Base Station

Remote unit

Server antenna

Band 2

Band 1

Donor unit

RF Link Path

Band 1

Link antennas

Repeater units

Link and server antenna on the

remote site can often be combined

By using another band for the link the isolation between antennas at the remote site becomes very low. It

might in some applications even be possible to use the same antenna for both the link and the service area.