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RF3181D (R) 4/7/15 Page 1 of 2
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Characteristic Sym Notes Minimum Typical Maximum Units
Center Frequency at 25°C Absolute Frequency
f
c
1, 2, 3
916.5 MHz
Tolerance from 916.50 MHz
Δf
c
kHz
Insertion Loss IL 1, 3 2.5 4.0 dB
3 dB Bandwidth
BW
3
1, 3
500 600 900 kHz
Rejection (Attenuation: relative to Min IL:) 10 to 895 MHz
1, 3
40 50
dB
895 to 906 MHz 30 35
906 to 910 MHz 25 30
922 to 925 MHz 35 40
925 to 933 MHz 14 18
933 to 940 MHz 30 35
940 to 1100 MHz 40 45
Temperature Freq. Temp. Coefficient FTC
3, 4
0.032
ppm/
°C
2
Frequency Aging Absolute Value during the First Year |fA| 5 ≤10 ppm/yr
Impedance @ f
C
Input Z
IN
= R
IN
/C
IN
Z
IN
1
37Ω // 1.6pF
Output Z
OUT
= R
OUT
/C
OUT
Z
OUT
25Ω // 1.8pF
Lid Symbolization (in addition to Lot and/or Date Codes) 671 // YWWS
Standard Reel Quantity 7 Inch Reel
9
500 Pieces/Reel
Standard Reel Quantity 13 Inch Reel 3000 Pieces/Reel
• Ideal Front-End Filter for 916.5 MHz Wireless Receivers
• Low-Loss, Coupled-Resonator Quartz Design
• Simple External Impedance Matching
• Complies with Directive 2002/95/EC (RoHS)
The RF3181D is a low-loss, compact, and economical surface-acoustic-wave (SAW) filter designed to provide
front-end selectivity in 916.5 MHz receivers. Receiver designs using this filter include superhet with 10.7 MHz
IF, direct conversion and superregen. Typical applications of these receivers are wireless remote-control and
security, data telemetry, and meter reading devices operating in the USA under FCC Part 15 and in Canada
under DoC RSS-210.
This coupled-resonator filter (CRF) uses selective null placement to provide suppression, typically greater
than 40 dB, of the LO and image spurious responses of superhet receivers with 10.7 MHz IF. Murata’s
advanced SAW design and fabrication technology is utilized to achieve high performance and very low loss
with simple external impedance matching (not included).
916.5 MHz
SAW Filter
RF3181D
SM3838-8 Case
3.8 x 3.8
CAUTION: Electrostatic Sensitive Device. Observe precautions for handling.
NOTES:
1. Unless noted otherwise, all measurements are made with the filter installed in the specified test fixture which is connected to a 50 Ω test system with VSWR ≤ 1.2:1. The
test fixture L and C are adjusted for minimum insertion loss at the filter center frequency, f
c
. Note that insertion loss and bandwidth and passband shape are dependent on
the impedance matching component values and quality.
2. The frequency f
c
is defined as the midpoint between the 3dB frequencies.
3. Where noted specifications apply over the entire specified operating temperature range of -40 to 90°C.
4. The turnover temperature, T
O
, is the temperature of maximum (or turnover) frequency, f
o
. The nominal frequency at any case temperature, T
c
, may be calculated from:
f=f
o
[1 - FTC (T
o
-T
c
)
2
].
5. Frequency aging is the change in fc with time and is specified at +65°C or less. Aging may exceed the specification for prolonged temperatures above +65°C. Typically,
aging is greatest the first year after manufacture, decreasing significantly in subsequent years.
6. The design, manufacturing process, and specifications of this device are subject to change.
7. One or more of the following U.S. Patents apply: 4,54,488, 4,616,197, and others pending.
8. All equipment designs utilizing this product must be approved by the appropriate government agency prior to manufacture or sale.
9. Tape and Reel Standard for ANSI/EIA 481.
Pb
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