3
Motorola Small–Signal Transistors, FETs and Diodes Device Data
NF, NOISE FIGURE (dB)
2.0
V
DS
, DRAIN–SOURCE VOLTAGE (VOLTS)
Figure 2. 100 MHz and 400 MHz Neutralized Test Circuit
0
10
2.0
4.0
6.0
8.0
0 4.0 6.0 8.0 10 12 14
I
D
= 5.0 mA
100 MHz
V
DS
= 15 Vdc
f1 = 399 MHz
f2 = 400 MHz
NF, NOISE FIGURE (dB)
2.0
I
D
, DRAIN CURRENT (mA)
1.5
6.5
2.5
3.5
4.5
5.5
0 4.0 6.0 8.0 10 12 14
Figure 3. Effects of Drain–Source Voltage Figure 4. Effects of Drain Current
NOISE FIGURE
(T
channel
= 25°C)
*L1 17 turns, (approx. — depends upon circuit layout) AWG #28
enameled copper wire, close wound on 9/32″ ceramic coil
form. Tuning provided by a powdered iron slug.
*L2 4–1/2 turns, AWG #18 enameled copper wire, 5/16″ long,
3/8″ I.D. (AIR CORE).
*L3 3–1/2 turns, AWG #18 enameled copper wire, 1/4″ long,
3/8″ I.D. (AIR CORE).
**L1 6 turns, (approx. — depends upon circuit layout) AWG #24
enameled copper wire, close wound on 7/32″ ceramic coil
form. Tuning provided by an aluminum slug.
**L2 1 turn, AWG #16 enameled copper wire, 3/8″ I.D.
(AIR CORE).
**L3 1/2 turn, AWG #16 enameled copper wire, 1/4″ I.D.
(AIR CORE).
Adjust V
GS
for
I
D
= 50 mA
V
GS
< 0 Volts
NOTE: The noise source is a hot–cold body
(AIL type 70 or equivalent) with a
test receiver (AIL type 136 or equivalent).
Reference
Designation
VALUE
100 MHz 400 MHz
C1
7.0 pF 1.8 pF
C2 1000 pF 17 pF
C3 3.0 pF 1.0 pF
C4 1–12 pF 0.8–8.0 pF
C5 1–12 pF 0.8–8.0 pF
C6 0.0015 µF 0.001 µF
C7 0.0015 µF 0.001 µF
L1 3.0 µH* 0.2 µH**
L2 0.15 µH* 0.03 µH**
L3 0.14 µH* 0.022 µH**
INPUT
TO 50
Ω
SOURCE
NEUTRALIZING
COIL
L1
C5
L3R
g
′
C1
C6
C4
L2
C3
TO 500
Ω
LOAD
CASE
C7
COMMON
I
D
= 5.0 mA
V
GS
V
DS
+15 V
C2
P
in
, INPUT POWER PER TONE (dB)
+40
Figure 5. Third Order Intermodulation Distortion
P , OUTPUT POWER PER TONE (dB)
out
16 18 20
f = 400 MHz
f = 400 MHz
100 MHz
V
DS
= 15 V
V
GS
= 0 V
+20
0
–20
–40
–60
–80
–100
–120
–140
–160
–120 –100 – 80 –60 – 40 –20 0 +20
3RD ORDER INTERCEPT
FUNDAMENTAL
OUTPUT @ I
DSS
,
0.25 I
DSS
3RD ORDER IMD
OUTPUT @ I
DSS
,
0.25 I
DSS
INTERMODULATION CHARACTERISTICS
