User's Manual

1. Product Description
Background
The performance of a cell phone can be easily degraded when in enclosed
structures where signals from a local cell site are not sufficient for reliable
phone operation. The Model 140 Miniature In-Building Amplifier (Mini-
IBA) was developed by Cellular Specialties, Inc. (CSI) to enhance cellular
performance within these enclosed structures. Specifically, the Mini-IBA is
designed to cover small areas such as home offices, small workshops, etc.
Functional Description
The Model 140 amplifier boosts the wireless network’s performance by
providing amplification of both transmit and receive signals. The unit
receives the portable phone’s signal through an inside antenna, amplifies it
and then sends it to an outside antenna. This signal is referred to as the
“Uplink”. The amplifier also receives signals from the Cell Site base station
through the outside antenna. This signal is amplified and re-radiated to the
portable phone and is referred to as the “Downlink”. It is necessary that
sufficient signal be available at the outside antenna.
The outside antenna is usually a directional type such as a “Yagi”, however
an Omni-directional antenna may be used when the structure is located in
close proximity to one or more cell sites. Inside antennas are usually Omni-
directional although other types, such as low profile wall or ceiling mount,
may be used for special installations.
As shown in Figure 1, there are four stages of gain in the Downlink and four
stages in the Uplink providing nominal gain of 40 dB in each link. The
maximum linear output power is 160 milliwatts for the Uplink and 160
milliwatts for the Downlink. These levels are factory set and are maintained
by an internal Automatic Gain Control (AGC) circuit.
Four LED indicators on the unit indicate:
• Green “Power” LED indicates that power is applied and the unit is
operating.
• Yellow “AGC” LED indicates that the gain of the Uplink and/or
Downlink is being reduced to maintain the maximum power
3 140 BDA Rev. 1
5/29/03