Blu STUDIO 5.0S II, Руководство по обслуживанию

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2. RF PARTS
Basic diagram:
The RF part of STUDIO 5.0S II consists of a transceiver (MT6166), GSM PA
(RF3232) ASM a WCDMA PA (RF7241/2/5/8) and an ASM.
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 (MT6582).
2 The transmit circuit will modulate the I/Q signals from the BB to pointed frequency,
amplify its power, and then transmit it to the antenna.
2.1 TX Part
2.1.1 TX Circuit
The modulation circuit is composed of PA and ASM. The PLL circuit is mainly
built in the MT6166. At first, the I/Q signals come into the MT6166 and then are
modulated into RF signals after going through the PLL circuit. The RF signals are sent out
to the PA RF7241/RF7242/RF7245/RF7248 (3G) or SKY77590 (2G). After sent into the
PA, the signals are amplified and transmitted as the electromagnetic wave by the antenna
after passing through the ASM between the MT6166 and RF7241/RF7242/RF7245/RF7248,
There are some circuits used as attenuation circuit, And the ASM (SKY77590 inside) do
the selects of RX TX.