5GHz RF Switch
ADS Simulation
ADS study application note for snow
May 2007
1
Design Conditions and Goal
• Frequency and bandwidth 5.15-5.35GHz
• Insertion Loss
• Return Loss
• Isolation
• Vcntl = 3.0 V HIGH, 0 V LOW
• Current consumption 3 mA
2
Board Substrate
3
电路结构
4
基本原理 - 1
• 控制电压为低,0V, PIN DIODE处于断开状态
5
基本原理 - 2
• 控制电压为高,3V, PIN DIODE处于导通状态
• 扇形等效为一个电容,接入点看成AC短路,经四分之一
波长变换成为AC开路
• 右边的PIN导通接到GND,经四分之一波长变换成为AC
开路
6
PIN DIODE ADS 模型
Toshiba JDP2S05FS
Port
P1
Num=1
Port
P2
Num=2
PinDiode
NLPIN1
Model=NLPINM1
Area=
Region=
Temp=
Mode=nonlinear
Af=1.0
Ffe=1.0
AllParams=
PinDiodeModel
NLPINM1
Is=1e-14
Vi=0
Un=900
Wi=10e-6
Rr=0
Cmin=0
Tau=10e-7
Rs=1.5
Cjo=0.32e-12
Vj=1.0
M=0.5
Fc=0.5
Imax=1.0
Imelt=1.0
Kf=0
7
RF Switch Schematic
MLIN
TL1
Subst="MSub1"
W=W50
L=2.5 mm
MLIN
TL2
Subst="MSub1"
W=W50
L=2.5 mm
MRSTUB
Stub1
Subst="MSub1"
Wi=W50
L=8.75 mm
Angle=45
MTEE_ADS
Tee2
Subst="MSub1"
W1=W50
W2=W50
W3=W50
Port
P1
Num=1
MLIN
TL5
Subst="MSub1"
W=W50
L=2.5 mm
MTEE_ADS
Tee4
Subst="MSub1"
W1=W50
W2=W50
W3=W50
MLIN
TL8
Subst="MSub1"
W=W50
L=0.1 mm
Port
Vcntl
Num=4
R_Pad1
R1
R=1 kOhm
W=W0402
S=S0402
L1=L0402
Var
Eqn
VAR
VAR1
W0402=0.6 mm
S0402=0.36 mm
L0402=1.18 mm
W50=0.535 mm
MTEE_ADS
Tee1
Subst="MSub1"
W1=W50
W2=W50
W3=W50
MLIN
TL3
Subst="MSub1"
W=W50
L=7.5 mm
MSub
MSUB
MSub1
H=0.254 mm
Er=3.48
Mur=1
Cond=5.8e7
Hu=1.0e+033 mm
T=0.045 mm
TanD=0.004
Rough=0.001 mm
toshiba_pin_diode
D1
MTEE_ADS
Tee3
Subst="MSub1"
W1=W50
W2=W50
W3=W50
MLIN
TL4
Subst="MSub1"
W=W50
L=2.5 mm
Port
P2
Num=2
MLIN
TL6
Subst="MSub1"
W=W50
L=7.5 mm
toshiba_pin_diode
D2
Port
RF_GND
Num=5
MLIN
TL7
Subst="MSub1"
W=W50
L=2.5 mm
Port
P3
Num=3
8