U3742bm – Rainbow Electronics U3742BM User Manual
Page 6
6
U3742BM
4735A–RKE–11/03
Table 1. Calculation of LO and IF Frequency
Figure 5. Input Matching Network with SAW Filter
Figure 6. Input Matching Network without SAW Filter
Conditions
Local Oscillator
Frequency
Intermediate Frequency
f
RF
= 315 MHz, MODE = 0
f
LO
= 314 MHz
f
IF
= 1 MHz
f
RF
= 433.92 MHz, MODE = 1
f
LO
= 432.92 MHz
f
IF
= 1 MHz
300 MHz < f
RF
< 365 MHz, MODE = 0
365 MHz < f
RF
< 450 MHz, MODE = 1
f
LO
f
RF
1
1
314
----------
+
--------------------
=
f
IF
f
LO
314
----------
=
f
LO
f
RF
1
1
432.92
------------------
+
----------------------------
=
f
IF
f
LO
432.92
------------------
=
IN
IN_GND
OUT
OUT_GND
CASE_GND
B3555
U3742BM
C
3
22p
L
25n
C
16
100p
C
17
8.2p
L
3
TOKO LL2012
F27NJ
27n
C
2
8.2p
L
2
TOKO LL2012
F33NJ
33n
1
2
3, 4
7, 8
5
6
8
9
RF
IN
f
RF
= 433.92 MHz
LNAGND
LNA_IN
IN
IN_GND
OUT
OUT_GND
CASE_GND
B3551
U3742BM
C
3
47p
L
25n
C
16
100p
C
17
22p
L
3
TOKO LL2012
F47NJ
47n
C
2
10p
L
2
TOKO LL2012
F82NJ
82n
1
2
3, 4 7, 8
5
6
8
9
LNAGND
LNA_IN
RF
IN
f
RF
= 315 MHz
U3742BM
15p
25n
100p
3.3p
TOKO LL2012
F22NJ
22n
8
9
LNAGND
LNA_IN
U3742BM
33p
25n
100p
3.3p
TOKO LL2012
F39NJ
39n
8
9
RF
IN
f
RF
= 315 MHz
LNAGND
LNA_IN
f
RF
= 433.92 MHz
RF
IN