Download - Pegasus 平台 RF 电路培训
Pegasus 平台 RF 电路培训
2005 01 26 LIBACH
系统介绍
Pegasus platform( 神马平台 )• 4-chip solution CX74063:Transceiver( 收发模块 ) CX77321:PA( 功率放大器模块 ) CX20524:IA( 集成模拟及电源管理芯片 ) CX80502:BP( 基带处理器芯片 )• RF chips: CX74063,CX77321
系统框图
系统原理示意简图
收发模块
CX74063 (收发模块)• Transmitter (发射单元)• Receiver (接收单元)• Synthesizer (频率合成单元)
Charge PumpIcp=2mA
3rd Order LP Filterfc = 110MHz
DCS LNA G=15dB/-3dB NF=3.0dB typ Ipeak=7.1mA
PCS LNA G=15dB/-3dB NF=3.0dB typ Ipeak=7.1mA
LPF (Sallen Key)G=10dB/-2dB typFc=300KHz typ
VGA1 (gmC Filter)G=0-34dB/2dB steps
Fc=105KHz typAUX VGA1G=6dB/0dB
VGA2 (gmC Filter)G=0-30dB/6dB steps
DCOC3
D2 DividerD2=2 for GSM
D2=1 for DCS/PCS
D1 DividerD1=9,10,11
or 12
D2
Phase DetectorFc(GSM)=41-50MHz
Fc(DCS/PCS)=80-102MHz
Tx IQModulatorIpeak=3mA
TIC LoopIpeak=5mA
Input 1 for DCS/PCSInput 2 for GSM
IP2Calibration
V_RFTx_En1Rx_En1Syn_En
Syn_Dat
Syn_ClkSyn_LE
X 2
2
LO GenerationIpeak=22-30mA
Modulo
DCOC2 DCOC1DCOCTIMER
3
DFC
PhaseDetector
Fc=9.75MHz
ChargePump
Icp=0.4mA
Tx VCO880-915MHzKv=25MHz/V
1710-1785MHz1850-1910MHzKv=50MHz/VPout=+10dBmIpeak = 50mA
N4th OrderLoop FilterFc=30KHz
4th Order Loop FilterFc=1MHz
D1
1 2UHF VCO1353-1506MHzKv=23MHz/VIpeak = 12mA
1/2 LO MixerIpeak=10mA Input 1 for
DCS/PCSInput 2 for GSM
1
19.5MHz fromCX20505
1Vp-p
V_UHFV_TIC
ControlRegister
HighbandPCS_SELFE_ENA
ConexantCX74017
Transceiver IC64 pin LGA
LPF Adj
DFC
2
TxIF=80-102MHz
Fract N. PLLIpeak=13mA
RX Baseband ChainIpeak=6mA
收发模块
收发模块
特点:• 直接下变频接收器• 三频( GSM,DCS,PCS )
• DFC (Digital Frequency Centering) 数字锁频技术
• 供三频使用的内置本振( LO )
• 内置发射压控振荡器( VCO )
• 内置 PA 功率控制电路
接收通路
Fractional-N
PLL
x 2
/3
Example shown atGSM ch. 62DCS ch. 700PCS ch. 661
GSM: fLO = fVCO/3DCS/PCS: fLO = 2fVCO/3
GSM VCO:1421.1MHzDCS VCO:1382.1MHzPCS VCO:1470.0MHz
GSM LO:473.7MHz
GSM Path
DCS/PCS Path
1/2 LO GSM Mixer
DCS LO:921.4MHzPCS LO:980.0MHz
1/2 LO HB MixerPCS LNA
GSM LNA
DSC LNA
x 2
x 2
GSM LO:947.4MHz
DCS LO1842.8MHzPCS LO:1960.0MHz
DCS RX1842.8MHz
GSM LO:947.4MHz
PCS Rx:1960.0MHz
To baseband RX
To baseband RX
TR Switch
UHFVCO
接收通路原理示意
发射通路
PhaseDetect
LoopFilter
Fractional-N
PLL
Tx I
Tx Q
TxVCO
UHFVCO
+
90°
x 2
/3
x 2
Example shown atGSM ch. 62DCS ch. 700PCS ch. 661
fTx = fLO(2.D1 - D2)/D1GSM: fLO = fVCO/3
DCS/PCS: fLO = 2fVCO/3
GSM VCO:1476.655MHzDCS VCO:1379.842MHzPCS VCO:1477.143MHz
GSM LO:492.218MHzDCS LO:919.895MHzPCS LO:984.762MHz
DCS/PCS Path
GSM Path
GSM LO:492.218MHzDCS LO:919.895MHzPCS LO:984.762MHz
High Side Inj.1/2 LO Mixer
GSM TX:902.4MHzDCS TX:1747.8MHzPCS TX:1880.0MHz
GSM LO:984.437MHzDCS LO:1839.789MHzPCS LO:1969.524MHz
InternalLPF
GSM TXIF:82.036MHzDCS TXIF:91.489MHzPCS TXIF:89.523MHz
External100MHz LPF
GSM :12DCS:10PCS:11
GSM :2DCS:1PCS:1
/D2
/D1
GSM PDin:41.018MHzDCS PDin:91.489MHzPCS PDin:89.523MHz
发射通路原理示意
CX77321 功率放大器
• CX77321• 小尺寸封装 6mm X 6mm X 1.2mm• 三频 EGSM, DCS and PCS• 支持 GPRS class 10(multi slot) 协议
CX77321 - PA 原理框图
CMOSBias
Controller
EGSM IN+6 to +10 dBm
EGSM OUT +5 to +35 dBm
DCS/PCS IN+6 to +10 dBm
Power Control
Band Select
VCC= 3.5 v nom (2.9 - 4.8 volts)
Match
Match
Match
DCS/PCS OUT0 to +33 dBm
Match
BiCMOS
Final stagesDriver stages
• 射频输入输出均为 50ohm• 两路独立放大( EGSM,DCS )• 支持三频, GPRS CLASS10• 高效率 : EGSM (53%), DCS (47%)
Efficiency Pout (@Vcc=3.5)GSM 53% 35 dBmDCS 47% 33 dBm PCS 47% 33 dBm
Pout (@Vcc=3.5) GSM 35.2 dBm DCS 33.2 dBm PCS 33.2 dBm
TxEnable
PA 功率控制电路
TX VCO
CX
773
02
Dual Band Coupler19 dB GSM14 dB DCS
T/R Switch
Active DiodeDetector
Pmin = -20 dBmPmax = +20 dBm
DifferentialIntegrator
DA
C
SummingAmplifier
Offset
Inte
rgra
tor
Ou
pu
t +
Off
set
AP
C
GSM:32dBm-19dB=+13dBm 5dBm-19dB=-14dBm
DCS/PCS29.4dBm-14dB=+15.4dBm
0dBm-14dB=-14dBm
Detector Dynamic Range
Airforce 平台功率控制电路
Pegasus 平台功率控制电路
• 差分放大器集成到 transceiver 中,大大减少了外围器件的数目,减小了布板面积
射频重要线路:
• 1. RF 射频线 : PLL 环路外围线路 , PA 到 ANT 和 ANT 到滤波器 .
• 2. APC 控制线 : PAC_Out, APC_CTL.• 3. TX_I/Q 和 RX_I/Q 信号线 .• 4. 19.5MHz crystal/13MHz 信号线 .• 5. Vbat line 从电池连接器到 PA
Question :• 收发器模块主要由哪几部分组成?•射频部分重要的线路有哪些?•功率放大器模块的基本特点是什么?
QUESTION???