用ADS设计
功率放大器
EEsof
Cheng-cheng, Xie
Application Engineer
Page 1
EEsof,Cheng-cheng,Xie
Feb,16,2006
主要内容:
• PA的主要指标
• DC分析
• 偏置电路的建立
• 稳定性分析
• 输入输出匹配电路设计
• 优化设计
• Layout
• PI4DQPSK 调制下测试ACPR
Page 2
EEsof,Cheng-cheng,Xie
Feb,16,2006
PA的主要指标
• 工作频带
• 稳定性
• 输出功率 饱和功率(Psat)
稳定系数K
1dB压缩点输出功率(P-1)
• 增益、增益平坦度
• 效率
功率效率
射频输出功率 −
射频输入功率
直流输入功率
EEsof,Cheng-cheng,Xie
Feb,16,2006
=addη
功率附加效率
三阶交调系数IM3 五阶交调系数IM5
二次、三次谐波
ACPR AltCPR (Alternate CPR)
• 线性度
• 输入输出驻波比
Page 3
指标实例
• 输出功率: 50 W(47dBm)
• 输入功率 : 1 W
• 效率 (η) > 50%
• 二次谐波抑制:40dBC
• 偏置电压: 28 V
• 选用放大器: MRF9045M
Page 4
EEsof,Cheng-cheng,Xie
Feb,16,2006
DC仿真
FET Curve Tracer
V_DC
SRC1
Vdc=VDS
Var
Eqn
VAR
VAR1
VDS =0 V
VGS =0 V
I_Probe
IDS
V_DC
SRC2
Vdc=VGS
VJ
FSL_MRF_MET_MODEL
MRF1
MODEL=MRF9045M
PARAMETER SWEEP
DC
FSL_TECH_INCLUDE
ParamSweep
Sweep1
SweepVar="VGS"
SimInstanceName[1]="DC1"
SimInstanceName[2]=
SimInstanceName[3]=
SimInstanceName[4]=
SimInstanceName[5]=
SimInstanceName[6]=
Start=2.5
Stop=5.0
Step=0.1
DC
DC1
SweepVar="VDS"
Start=0
Stop=28*2
Step=0.1
Disp
Temp
DisplayTemplate
disptemp1
"FET_curve_tracer"
FSL_TECH_INCLUDE
FTI
设置需要的Vg、
Vd扫描范围
Page 5
EEsof,Cheng-cheng,Xie
Feb,16,2006
DC仿真
i
e
n
L
_
d
a
o
L
,
i
.
S
D
A
I
5
4
3
2
VDsat
1
0
IQ
m3
0
5
10 15
20
25
30
35
40
45
50
55
60
Eqn Pout=50
Eqn Vsat=indep(VDsat)
Eqn Vq=indep(IQ)
Eqn Vmax=indep(m3)
Eqn Imin=m3
Eqn Iq=IQ
VDS
Eqn RL=0.5*((Vq-Vsat)**2)/Pout
VDsat
VDS=
0.600
IDS.i=0.562
VGS=3.800000
IQ
VDS=
28.000
IDS.i=0.717
VGS=3.800000
m3
VDS=
33.000
IDS.i=0.055
VGS=3.100000
Eqn Load_Line=(Vmax-VDS)/RL+Imin
Eqn Pq=Iq*Vq
Pq
RL
20.089
7.508
从负载曲线可以看出,此
放大器工作于AB类。
Page 6
EEsof,Cheng-cheng,Xie
Feb,16,2006
按DC仿真结果添加偏置电路、封装放大器
MLIN
TL20
Subst="MSub1"
W=63.668898 mil
L=100 mil
MLIN
TL21
Subst="MSub1"
W=63.668898 mil
L=100 mil
Port
P3
Num=3
sc_spr_293D_A025_X9_19960828
C19
PART_NUM=293D474X9025A2 0.47uF
sc_mrt_MC_GRM40C0G050_D_19960828
C20
PART_NUM=GRM40C0G100D050 10pF
sc_mrt_MC_GRM40C0G050_J_19960828
C25
PART_NUM=GRM40C0G330J050 33pF
sr_avx_CR_10_K_19960828
R13
PART_NUM=CR10-150K 15 Ohm
MLIN
TL1
Subst="MSub1"
W=63.670079 mil
L=2194.444882 mil
sc_mrt_MC_GRM40C0G050_J_19960828
C8
PART_NUM=GRM40C0G330J050 33pF
Port
P2
Num=2
VD
Port
P1
Num=1
sc_mrt_MC_GRM40C0G050_J_19960828
C7
PART_NUM=GRM40C0G330J050 33pF
sc_mrt_MC_GRM40C0G050_J_19960828
C3
PART_NUM=GRM40C0G330J050 33pF
VG
VJ
sr_avx_CR_10_K_19960828
R12
PART_NUM=CR10-680K 68 Ohm
FSL_MRF_MET_MODEL
MRF1
MODEL=MRF9045M
TSNK=25
RTH=-1
CTH=-1
MLIN
TL22
Subst="MSub1"
W=63.668898 mil
L=100 mil
MLIN
TL23
Subst="MSub1"
W=63.668898 mil
L=100 mil
sl_tok_LL2012-F_J_19960828
L2
PART_NUM=LL2012-F82NJ 82 nH
Port
P4
Num=4
sc_spr_293D_A025_X9_19960828
C24
PART_NUM=293D474X9025A2 0.47uF
sc_mrt_MC_GRM40C0G050_D_19960828
C23
PART_NUM=GRM40C0G100D050 10pF
sc_mrt_MC_GRM40C0G050_J_19960828
C17
PART_NUM=GRM40C0G330J050 33pF
MSub
MSUB
MSub1
H=33.6 mil
Er=4.2
Mur=1
Cond=5.8E+08
Hu=3.9e+034 mil
T=2.8 mil
TanD=0.002
Rough=0 mil
Page 7
MRF9045M_AMP
X4
EEsof,Cheng-cheng,Xie
Feb,16,2006
稳定性测试
VDD
VGG
MRF9045M_AMP
X1
P_1Tone
PORT1
Num=1
Z=50 Ohm
P=polar(dbmtow (-60),0)
Freq=fss
S-PARAMETERS
FSL_TECH_INCLUDE
S_Param
SP2
Start=1 MHz
Stop=3000 MHz
Step=1.0 MHz
FSL_TECH_INCLUDE
FTI
StabFact
StabMeas
Mu
MuPrime
StabFact
StabFact1
StabFact1=stab_fact(S)
StabMeas
StabMeas1
StabMeas1=stab_meas(S)
Mu
Mu1
Mu1=mu(S)
MuPrime
MuPrime1
MuPrime1=mu_prime(S)
两组稳定性判定函
数任取一组即可
Term
R3
Num=2
Z=50 Ohm
VDD
I_Probe
IDD
V_DC
SRC1
Vdc=VDS
VGG
I_Probe
IGG
Var
Eqn
V_DC
SRC2
Vdc=VGS
VAR
VAR3
VDS =28 V
VGS =3.8 V
Page 8
EEsof,Cheng-cheng,Xie
Feb,16,2006