The Communications Edge TM
FP31QF
2-Watt HFET
Product Information
Reference Design: 2400 – 2500 MHz
The application circuit is matched for output power.
Typical RF Performance
Drain Bias = +9 V, Ids = 450 mA, 25 °C
Measured S-Parameters
15
10
5
Frequency
MHz
dB
2400
12.1
-13
2500
12.0
-16
S21 – Gain
S11 – Input Return Loss
S22 – Output Return Loss
Output P1dB
dB
0
DB(|S[1,1]|)
DB(|S[2,1]|)
DB(|S[2,2]|)
dB
-13
-17
-5
dBm
+33.5
-10
-15
-20
-25
Output IP3
(+18 dBm / tone, 1 MHz spacing)
dBm
dB
+46.8
4.6
Noise Figure
The 2.4 – 2.5 GHz Reference Circuit is shown for design purposes only. An
evaluation board is not readily available for this application. The reader can
obtain any FP31QF evaluation board and modify it with the circuit shown to
achieve the performance shown in this reference design.
2.3
2.35
2.4
2.45
2.5
2.55
2.6
Frequency (GHz)
Bill of Materials
Ref. Desig.
C1, C4, C8, C10
C2, C3
C7, C11
C12
Value
Part style
Size
22 pF
1.5 pF
Chip capacitor
Chip capacitor
Chip capacitor
Chip capacitor
0603
0603
0603
1206
0805
0603
0603
0603
QFN 6x6
1000 pF
0.1 µF
12 nH
3.3 nH
5.1 Ω
L1, L2
L3
R1
Wirewound chip inductor
Multilayer chip inductor
Chip resistor
C2
C3
R2
Q1
50 Ω
FP31QF
Chip resistor
WJ 2W HFET
Do Not Place
C5, C6
•
•
•
•
The C2 and C3 placements are at silk screen markers, “A” and “2”, respectively.
The via hole spacing along the main microstrip line is .040”.
The distance from the edge of the FP31QF to the closer edge of L3 is .305”.
The transmission line lengths shown in the schematic are from the FP31QF
device edge to the component edge.
Circuit Board Material: .014” FR-4 (εr = 4.6),
4 layers (other layers added for rigidity), .062” total thickness, 1 oz copper
The main microstrip line has a line impedance of 50 Ω.
ID=C7
C=1000 pF
ID=C8
C=22 pF
-Vgg
Vds=9V @ 450 mA
ID=C12
C=1e5 pF
ID=R2
R=51 Ohm
ID=C11
C=1000 pF
ID=C10
C=22 pF
TLINP
ID=TL1
Z0=50 Ohm
L=150 mil
Eeff=3.46
NET="FP31QF"
ID=L1
L=12 nH
ID=L2
L=12 nH
ID=C4
C=22 pF
2
ID=L3
ID=C1
Loss=0
L=3.3 nH
C=22 pF
F0=0 MHz
1
ID=R1
R=5.1 Ohm
TLINP
ID=TL2
Z0=50 Ohm
L=180 mil
Eeff=3.46
Loss=0
ID=C2
C=1.5 pF
ID=C3
C=1.5 pF
F0=0 MHz
Specifications and information are subject to change without notice
Page 9 of 12 October 2006
WJ Communications, Inc • Phone 1-800-WJ1-4401 • FAX: 408-577-6621 • e-mail: sales@wj.com • Web site: www.wj.com
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