Blu LIFE 8, Service Manual, Page: 12 / 29

3.
RF PARTS
3.1 Basic diagram:
The RF part of LIFE 8 consists of a transiver (MT6166) and a PA (SKY77590). The two
functions of the RF circuit as below:
1, The receiver circuit will receive the high frequency signal from the antenna, select out
the necessary signals and demodulate them into I/Q signals, transmit them to the BB chip
(MT6592).
2,The transmit circuit will modulate the I/Q signals from the BB and amplify it, then
transmit it to the antenna.
The signal from MIC to CPU and transceiver, include I/Q signals, they are low frequency
signal, so are baseband signals. From transceiver to antenna, the signals are in high
frequency, so they are high frequency signals.
Baseband signals use oscillograph and high frequency signals use spectrum analyzer to
measure.