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RF2418
Rev A7 DS060203
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.
Application Schematic
Buffered Output Configuration
850MHz
1
2
3
4
5
6
7
14
13
12
11
10
9
8
LN A
M IXER
B U FFE R
10pF
RF A M P
I
F
F
i
l
t
e
r
,
5
0
Ω
IF O U T
R F IN
I
m
a
g
e
F
i
l
t
e
r
,
5
0
Ω
15nH
10 nH
LO IN
V DD
V DD
L1 s hould par alle l r e s onate, at the IF fr equen c y , w ith the in te r nal
10pF c apac itor plus any ex tr a par as itic la y out c apac itanc e .
R 1 and R 2 ar e bias r e s is tor s that s e t the bias c u r r ent fo r the buffe r
am plifie r . T he v a lue r e c o m m ended is 510 W , eac h. H ighe r v a lues
w ill dec r eas e the c u r r e n t c ons um ption but als o dec r eas e the output
le v e l at w h ic h v o ltage c lipping begins to oc c u r . A t lo w e r IF
fr equenc ie s , w her e the in te r nal 10 pF c apac itor does not r o ll off the
c onv er s ion gain, L1 m a y be elim inated .
C 1 is a bloc k ing c apac itor , in c a s e the IF filter 's input is not an open
c ir c uit at D C .
10 nH
47 pF
100 nF
R1
C1
L1
R2
100 nF
100 nF
1 n F
4 p F
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