User's Manual

VS500 USER MANUAL
Confidential & Proprietary of VACOM 12/13 Page Date : 05-08-08, Rev No : 1.0
Control No.: MSD351A0VS500
Originated by Hard Ware 3 Team
antenna.
3.4.2.1 RFT6122 : (U541)
The RFT6122 provides the Zero-IF transmitter signal path, from analog baseband to RF drive amplifier,
for single band single-mode. Secondary functions are integrated on chip , two PLL circuits(TX LO and
RX LO), TX VCO circuit, TX LO generation and distribution circuits, and various interface, control, etc..
Quadrature
Upconverter
LO Generation
&Distribution
Tx
VCO
Tx PLLRx PLL
Logic
Gain Ctl
Circuits
Control
Circuits
S
B
I
m ode
RFT6122
Fref
Fref
lock
lock
m ode
RF_OUT (23)
VCONTROL (21)
LOCK (8)
(29) TX_IP
(30) TX_IM
(27) TX_QP
(28) TX_QM
(7) VDDM
(9) TX_ON
(32) SBCK
(2) SBST
(1) SBDT
(6) R_BIAS
VDDA
VDDRF
(31) DAC_REF
TCXO (4)
TX _CP _HO LD (13 )
TX _CP (12 )
RX_LO_IN (15)
RX_CP (18)
RX_CP_HOLD (19)
Gr ound slug
GND
3.4.2.2 RF SAW FILTER: (SW571)
It eliminates other signals except transmit frequency of CDMA handset (836.5±12.5MHz) and
bandwidth is 25MHz.
Division Specification
Insertion loss 2.5 dB max
In-out VSWR 2.0 max
In band ripple 1.5 dB
Stop band attenuation (Tx band) 30 dB min
3.4.2.3 POWER AMPLIFIER (PA): (U572)
Power AMP is to amplify the signal to reach Base Station.
Division Specification
Power output level 28 dBm (CDMA) // 31 dBm(AMPS)
Power gain 27.5 dB typ
Power added efficiency 40 % typ @ max power
Input VSWR 2 : 1
Load matching stress VSWR 8 : 1