®
RF1284
319.500 MHz
SAW Filter
•
•
•
•
•
Ideal Front-End Filter for European Wireless Receivers
Low-Loss, Coupled-Resonator Quartz Design
Simple External Impedance Matching
Rugged TO39 Hermetic Package
Complies with Directive 2002/95/EC (RoHS)
Pb
The RF1284 is a low-loss, compact and economical surface-acoustic-wave (SAW) filter designed to provide
front-end selectivity in 319.500 MHz receivers. Recevier designs using this filter include superhet with
10.7 MHz or 500 kHz IF, direct conversion and superregen.
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 ad-
vanced SAW design and fabrication technology is utilized to achieve high performance and very low loss with
simple external impedance matching (not included). Quartz construction provides excellent frequency stabil-
ity over a wide temperature range.
TO39-3 Case
Electrical Characteristics
Characteristic
Center Frequency at 25°C
Insertion Loss
3 dB Bandwidth
Rejection
at f
c
- 21.4 MHz (Image)
at f
c
- 10.7 MHz (LO)
Ultimate
Temperature
Operating Case Temperature
Turnover Temperature
Turnover Frequency
Frequency Temperature Coefficent
Frequency Aging
External Impedance
Absolute Value during the First Year
Series Inductance
Shunt Capacitance
Lid Symbolization (in addition to Lot and/or Date Codes)
T
C
T
O
f
O
FTC
IfAI
L
C
5
1
1
100
10
RFM // RF1284 // DATECODE
3, 4
-40
15
25
f
C
0.032
≤10
1
Absolute Frequency
Tolerance from 319.500 MHz
Sym
f
C
∆f
C
IL
BW
3
Notes
1, 2
1
1, 2
500
40
15
2.0
600
50
40
80
+85
35
°C
°C
MHz
ppm/°C
2
ppm/yr
nH
pF
dB
Minimum
319.420
Typical
Maximum
319.580
±80
3.0
800
Units
MHz
kHz
dB
kHz
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, 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.
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
5.
6.
7.
8.
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 without notice.
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.
RF Monolithics, Inc.
Phone: (972) 233-2903
Fax: (972) 387-8148
RFM Europe
Phone: 44 1963 251383
Fax: 44 1963 251510
©1999 by RF Monolithics, Inc. The stylized RFM logo are registered trademarks of RF Monolithics, Inc.
E-mail: info@rfm.com
http://www.rfm.com
RF1284-100705
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