Technical Note
Stabilizing Network
Model: PGA-103+
AN-60-064
The PGA-103+ is a monolithic amplifier for the 504000MHz range with excellent gain flatness and a high
dynamic range (1dB compression point: 20.6dBm @
2GHz).
S parameters for the PGA-103+ can be found here.
Unconditional stability requires stability factor k>1 and
stability measure B>0. However, PGA-103+ has k<1 for
frequencies under 100MHz.
The stability parameters of the amplifier with the
stabilizing network are shown in Figure 3. Note: k>1
and B>0 over entire range.
The performance of the stabilized amplifier:
Performace with and without stabilization is shown in
Figures 3 to 11
STABILITY FACTOR
1.5
R
O
T
C 1.0
A
F
Y
T
IL
I 0.5
B
A
T
S
0.0
10
100
1000
10000
Frequency (MHz)
PGA-103+
Figure 1 - PGA-103+: stability factor
In order to improve stability additional components
need to be added at input and output, see Figure 2:
TB-761-103+
Figure 3 – Stability Factor (k-factor)
STABILITY MEASURE
1.2
E
R1.0
U
S
A
E 0.8
M0.6
Y
T
IL 0.4
I
B
A
0.2
T
S
0.0
10
100
1000
10000
Frequency (MHz)
PGA-103+
Figure 2: Stabilization Circuit (TB-761-103+)
Component
DUT
C1,C2
C3
C4
C5
R1
L1(RF-Choke)
L2
Figure 4 –Stability Measure
Value
PGA-103+
0.01µF
0.33µF
10 μF
330 pF
150Ω
Mini Circuits TCCH-80+
620nH
TB-761-103+
GAIN
30
25
)B20
(d15
IN
A
G10
5
0
10
100
1000
10000
Frequency (MHz)
PGA-103+
TB-761-103+
Figure 5 – Gain
AN-60-064 Rev.: B M144698 (01/15/14) File: AN60064.doc
This document and its contents are the property of Mini-Circuits.
Page 1 of 2
Technical Note
Stabilizing Network
Model: PGA-103+
AN-60-064
OUTPUT IP3
55
ISOLATION
)
c
B
d
(
3
IP
40
)
B
d
(
45
T
U
P
T
U
O
40
30
35
N
O
I
T
A
L
O
IS
20
30
10
0
50
10
100
10
100
1000
10000
PGA-103+
Frequency (MHz)
PGA-103+
TB-761-103+
TB-761-103+
1dB COMPRESSION
) 25
m
B
23
d
(
N21
O
SIS
E 19
R
P
M17
O
C15
B
d
1 10
INPUT RETURN LOSS
25
)
B
d
(
S
S
O
L
20
15
10
5
0
10000
Figure 9 - Output IP3
Figure 6 – Isolation
N
R
U
T
E
R
T
U
P
N
I
1000
Frequency (MHz)
100
1000
10000
Frequency (MHz)
10
100
1000
10000
PGA-103+
Frequency (MHz)
PGA-103+
TB-761-103+
Figure 10 – Output power @ 1dB compression\
Noise Figure
Figure 7 - Input Return Loss
3.0
)B2.5
d(
reu2.0
gi 1.5
F
sei 1.0
oN0.5
0.0
OUTPUT RETURN LOSS
) 50
Bd
(S 40
SO
L 30
NR
UT 20
ER10
TU
PT 0
UO 10
TB-761-103+
10
100
1000
10000
Frequency (MHz)
100
1000
10000
PGA-103+
Frequency (MHz)
PGA-103+
TB-761-103+
TB-761-103+
Figure 11 - Noise Figure
Figure 8 - Output Return Loss
Conclusion:
•
Use of the stabilization circuitry has minor impact on all parameters.
•
The use of the stabilization circuitry guarantees amplifier’s unconditional stability.
AN-60-064 Rev.: B M144698 (01/15/14) File: AN60064.doc
This document and its contents are the property of Mini-Circuits.
Page 2 of 2