Service Manual

Interface Description EMIII-DUAL Servce Manual Application Information
EMIII-DUAL V1.0 AnyDATA.NET Proprietary – Use Subject to Restrictions
amplifiers, and Tx power control through an 85 dB VGA. As added benefit, the single sideband
upconversion eliminates the need for a bandpass filter normally required between the upconverter
and driver amplifier providing overall board area and cost savings. RFT3100 functionality is
specifically controlled from the MSM5100 via the three-line serial bus interface (SBI).
Designed to meet the requirements for global CDMA markets, the RFT3100 will operate over the
following Tx frequency ranges :
Cellular band 824MHz ~ 925MHz
PCS band 1750MHz ~1910MHz
2.3. Upconverter (U104)
Upconverters made up of a mixer part and Driver AMP part. The mixer part is used to receive
double-balanced OUT+ and OUT- of transmit AGC from baseband and mix the output of VCO (U171) with UHF
output signal, whereas the Amp part is used to buffer the output of this mixer. U105 has the operation range of
RF500MHz~1500MHz and has the conversion gain of 0 dB. In addition, the suppression of spurious signals which
are unwanted noise is about 30 dBc when being compared to RF output. The IF input signal range of the mixer is
DC~200MHz. The isolation on RF output terminal and LO signal input terminal at the IF input terminal is 30dB.
The range of LO signal that can be inputted is 300~1700MHz and power level is -6~0 dBm.
2.4. Transmit Bandpass Filter (FL101)
Transmit signals that have been converted from IF signals into RF signals after passing through the upconverter
U105 are inputted into the Power Amp U103 after passing once again through RF BPF F101in order to filter out
noise signals amplified during the amplification of RF signals after going through upconverter(U105). This is
carried out in order to create power level inputted to the Power AMP via RF BPF FL101 IL of two RF BPFs is
4dB as a maximum, whereas the ripple in the passing band is 2dB(maximum). The degree of the suppression of
transmit signals on receive band is at least 20dB or greater. The maximum power that can be inputted is about
25dBm.
2.5. Power Amplifier (U103)
The power amplifier U102 that can be used in the CDMA and FM mode has linear amplification capability,
whereas in the FM mode, it has a high efficiency. For higher efficiency, it is made up of one MMIC (Monolithic
Microwave Integrated Circuit) for which RF input terminal and internal interface circuit are integrated onto one IC