RF3181D
•
•
•
•
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)
Pb
916.5 MHz
SAW Filter
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. RFM’s advanced
SAW design and fabrication technology is utilized to achieve high performance and very low loss with simple
external impedance matching (not included).
SM3838-8 Case
3.8 x 3.8
Electrical Characteristics
Characteristic
Center Frequency at 25°C
Insertion Loss
3 dB Bandwidth
Rejection (Attenuation: relative to Min IL:)
10 to 895 MHz
895 to 906 MHz
906 to 910 MHz
922 to 925 MHz
925 to 933 MHz
933 to 940 MHz
940 to 1100 MHz
Temperature
Frequency Aging
Impedance @ f
C
Standard Reel Quantity
Standard Reel Quantity
Freq. Temp. Coefficient
Absolute Value during the First Year
Input Z
IN
= R
IN
/C
IN
Output Z
OUT
= R
OUT
/C
OUT
7 Inch Reel
13 Inch Reel
Lid Symbolization (in addition to Lot and/or Date Codes)
9
FTC
|fA|
Z
IN
Z
OUT
3, 4
5
1
1, 3
Absolute Frequency
Tolerance from 916.50 MHz
Sym
f
c
∆f
c
IL
BW
3
Notes
1, 2, 3
1, 3
1, 3
Minimum
Typical
916.5
2.5
Maximum
Units
MHz
kHz
4.0
900
dB
kHz
500
40
30
25
35
14
30
40
600
50
35
30
40
18
35
45
dB
ppm/
0.032
≤10
37Ω // 1.6pF
25Ω // 1.8pF
671 // YWWS
500 Pieces/Reel
3000 Pieces/Reel
°C
2
ppm/yr
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 band-
width and passband shape are dependent on the impedance matching component values and quality.
The frequency f
c
is defined as the midpoint between the 3dB frequencies.
Where noted specifications apply over the entire specified operating temperature range of -40 to 90°C.
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
].
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.
The design, manufacturing process, and specifications of this device are subject to change.
One or more of the following U.S. Patents apply: 4,54,488, 4,616,197, and others pending.
All equipment designs utilizing this product must be approved by the appropriate government agency prior to manufacture or sale.
Tape and Reel Standard for ANSI/EIA 481.
2.
3.
4.
5.
6.
7.
8.
9.
www.RFM.com
E-mail: info@rfm.com
©2008 by RF Monolithics, Inc.
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RF3181D - 3/21/08
RFM [ RF MONOLITHICS, INC ]
