SAW Components
Data Sheet B3573
2May 09, 2001
SAW Components B3573
869,60 MHzLow-loss Filter
Data Sheet
Features
■RF low-loss filter for remote control receivers
■Package for Surface Mounted Technology
(SMT)
Terminals
■Ni, gold plated
Pin configuration
1 Input
2,7 Input Ground
5 Output
3,6 Output Ground
4,8 Case - Ground
Electrostactic Sensitive Device (ESD)
Type Ordering code Marking and package
according to Packing
according to
B3573 B39871-B3573-U310 C61157-A7-A56 F61074-V8070-Z000
Maximum ratings
Operable temperature range
T
A–45/+90 ˚C
Storage temperature range
T
stg –45/+90 ˚C
DC voltage
V
DC 0V
Source power
P
S
0 dBm source impedance 50 Ω
typ. dimensions in mm, approx. weight 0,1 g
Ceramic package QCC8C
3May 09, 2001
SAW Components B3573
869,60 MHzLow-loss Filter
Data Sheet
Characteristics
Reference temperature:
T
A= 25 ˚C
Terminating source impedance:
Z
S= 50 Ωand matching network
Terminating load impedance:
Z
L= 50 Ωand matching network
1)Temperature dependence of
f
C
:
f
C
(
T
A) =
f
C
(
T
0
) (1 +
TC
f(
T
A –
T
0
)2)
2) Impedance for passband matching bases on an ideal, perfect matching of the SAW filter to
source- and to load impedance (here 50 Ohm). After the SAW filter is removed and input imped-
ance into the input matching / output matching network is calculated.
The conjugate complex value of these characteristic impedances are the input and output imped-
ances for flat passband. For more details, we refer to EPCOS application note #4.
min. typ. max.
Center frequency
f
C
— 869,69 — MHz
(center frequency between 3 dB points)
Minimum insertion attenuation αmin
869,20 ... 870,18 MHz — 2,8 4,3 dB
Pass band (relative to αmin)
869,20 ... 870,18 MHz — 1,2 3,0 dB
869,12 ... 870,26 MHz — 1,8 6,0 dB
Relative attenuation (relative to αmin)αrel
10,00 ... 700,00 MHz 50 55 — dB
700,00 ... 843,00 MHz 35 40 — dB
843,00 ... 865,20 MHz 28 33 — dB
865,20 ... 867,00 MHz 8 13 — dB
871,69 ... 872,50 MHz 8 13 — dB
872,50 ... 880,00 MHz 15 20 — dB
880,00 ... 910,00 MHz 24 29 — dB
910,00 ...1000,00 MHz 35 40 — dB
Impedance for pass band matching 2)
Input:
Z
IN =
R
IN ||
C
IN — 232 ||2,10 — Ω || pF
Output:
Z
OUT =
R
OUT ||
C
OUT —243 | |2,10 —Ω || pF
Temperature coefficient of frequency 1)
TC
f— –0,03 — ppm/K2
Frequency inversion point
T
0
—25—°C
4May 09, 2001
SAW Components B3573
869,60 MHzLow-loss Filter
Data Sheet
Matching network to 50 Ω(element values depend on pcb layout and equivalent circuit)
Cp1 = 3,3 pF
Ls2 = 12 nH
Ls3 = 12 nH
Cp4 = 3,3 pF
Minimising the crosstalk
For a good ultimate rejection a low crosstalk is necessary. Low crosstalk can be realised with
a good RF layout. The major crosstalk mechanism is caused by the “ground-loop” problem.
Grounding loops are created if input-and output transducer GND are connected on the top-side
of the PCB and fed to the system grounding plane by a common via hole. To avoid the common
ground path, the ground pin of the input- and output transducer are fed to the system ground
plane (bottom PCB plane) by their own via hole. The transducers’ grounding pins should be
isolated from the upper grounding plane.
A common GND inductivity of 0.5nH degrades the ultimate rejection (crosstalk) by 20dB.
The optimised PCB layout, including matching network for transformation to 50 Ohm, is shown
here. In this PCB layout the grounding loops are minimised to realise good ultimate rejection.
Optimised PCB layout for SAW filters in QCC8 package, pinning 1,5 (top side, scale 1:1)
The bottom side is a copper plane (system ground area). The input and output grounding pins
are isolated and connected to the common ground by separated via holes.
For good contact of the upper grounding area with the lower side it is necessary to place
enough via holes.
5May 09, 2001
SAW Components B3573
869,60 MHzLow-loss Filter
Data Sheet
Normalized frequency response
Normalized frequency response (wideband)
6May 09, 2001
SAW Components B3573
869,60 MHzLow-loss Filter
Data Sheet
Published by EPCOS AG
Surface Acoustic Wave Components Division, SAW CE AE PD
P.O. Box 80 17 09, D-81617 München
EPCOS AG 2001. All Rights Reserved.
A
s far as patents or other rights of third parties are concerned, liability is only assumed for compo-
nents per se, not for applications, processes and circuits implemented within components or
assemblies.
T
he information describes the type of component and shall not be considered as assured
characteristics.
T
erms of delivery and rights to change design reserved.
For questions on technology, prices and delivery please contact the sales offices of EPCOS AG or
t
he international representatives.
Due to technical requirements components may contain dangerous substances. For information on
t
he type in question please also contact one of our sales offices.
