3 April 04, 2007
B3773
868.95 MHz
SAW Components
SAW filter
Data sheet
Please read
cautions and warnings and
important notes
at the end of this document.
Characteristics
Temperature range for specification: T = –45 ˚C to +120 ˚C
Terminating source impedance: Z
S
=50Ωand matching network
Terminating load impedance: Z
L
=50Ωand matching network
min. typ.
@ 25 ˚C
max.
Center frequency f
C
— 868.95 — MHz
Minimum insertion attenuation α
min
incl. loss in matching elements (Q
L
= 47) — 3.0 3.7 dB
excl. loss in matching elements — 2.5 3.2 dB
Pass band (relative to α
min
)
868.80 ... 869.10 MHz — 0.5 2.0 dB
868.70 ... 869.20 MHz — 1.1 3.0 dB
Filter bandwidth
α
rel
≤ 3 dB 1.25 1.35 1.45 MHz
Relative attenuation (relative to α
min
) α
rel
10.00 ... 850.00 MHz 55 59 — dB
850.00 ... 858.00 MHz 50 55 — dB
858.00 ... 866.15 MHz 30 35 — dB
871.65 ... 880.00 MHz 23 27 — dB
880.00 ... 890.00 MHz 40 47 — dB
890.00 ... 1000.00 MHz 55 59 — dB
Impedance for pass band matching
1)
1)
Impedance for passband matching bases on an ideal, perfect matching of the SAW filter to source- and to load
impedance (here 50 Ohm). After removal of the SAW filter the input impedance of the input and output match-
ing network is calculated. The conjugate complex value of these characteristic impedances are the input and
output impedances for flat passband. For more details we refer to EPCOS application note #4.
Input: Z
IN
=R
IN
|| C
IN
— 270 || 1.0 — Ω || pF
Output: Z
OUT
=R
OUT
|| C
OUT
—
270 || 1.0
— Ω || pF
