RF1284
•
•
•
•
•
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
319.508 MHz
SAW Filter
The RF1284 is a low-loss, compact and economical surface-acoustic-wave (SAW) filter designed
to provide front-end selectivity in 319.508 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 advanced 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 stability 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
Impedance @ fc
Absolute Value during the First Year
Input Z
IN
=R
IN
//C
IN
Output Z
OUT
=R
OUT
//C
OUT
Lid Symbolization (in addition to Lot and/or Date Codes)
T
C
T
O
f
O
FTC
IfAI
Z
IN
Z
OUT
5
1
1
3, 4
-40
15
25
f
C
0.032
≤10
1570Ω//6.84pf
1490Ω//7.02pf
RFM // RF1284 // YYWWS##
1
Absolute Frequency
Tolerance from 319.500 MHz
Sym
f
C
∆f
C
IL
BW
3
Notes
1, 2
1
1, 2
Minimum
319.428
Typical
Maximum
319.588
±80
Units
MHz
kHz
dB
kHz
dB
2.0
500
40
15
600
50
40
80
3.0
800
+85
35
°C
°C
MHz
ppm/°C
2
ppm/yr
nH
pF
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.
The frequency f
c
is defined as the midpoint between the 3dB frequencies.
Where noted, specifications apply over the entire specified operating temperature range.
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 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.
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www.RFM.com
E-mail: info@rfm.com
©2008 by RF Monolithics, Inc.
Page 1 of 6
RF1284 - 3/21/08
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