Tower Top Low Noise Amplifier (TTLNA) requirements
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General

The following diagram shows how a TTLNA can be inserted in each antenna RF feeder cable, close to the antenna, in order to amplify the signal received from the antenna by 12dB. This TTLNA is powered using a DC bias voltage that is supplied from the filter in the base station via the RF coaxial antenna cable.

The TTLNA incorporates two duplexer, allowing the transmit and receive signal paths to be separated and recombined, so that an LNA can be incorporated in the receive path. If a faulty LNA is detected, a bypass function can be enabled that allows the un-amplified receive signal to be still supported.

Although a TTLNA is totally independent from others, two TTLNAs may be housed in a Dual TTLNA unit that would be used to support both antenna paths in a single sector.

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