Filename: tfs 248c.doc
Version 1.4
06.08.2004
VI
TELEFILTER
Measurement condition
Ambient temperature:
Input power level:
Terminating impedance: *
Input:
Output:
23
0
°C
dBm
Filter specification
TFS 248C
1/5
63
Ω
|| -1,65 pF
63
Ω
|| -0,42 pF
Characteristics
Remark:
The reference level for the relative attenuation arel of the TFS 248C is the minimum of the pass band attenuation amin. The minimum of the pass band
attenuation amin is defined as the insertion loss ae. The centre frequency fc is the arithmetic mean value of the upper and lower frequencies at the 3,0 dB
filter attenuation level relative to the insertion loss ae. The nominal frequency fN is fixed at 248,6 MHz without any tolerance. The given values for both the
relative attenuation arel and the group delay ripple have to be achieved at the frequencies given below even if the centre frequency fc is shifted due to the
temperature coefficient of frequency TCf in the operating temperature range and due to a production tolerance for the centre frequency fc.
Data
Insertion Loss
(reference level)
Nominal Frequency
Centre Frequency
3 dB Band width
Pass Band Ripple
fN
±
120 kHz
Relative Attenuation
fN – 248,5 MHz
fN + 10
MHz
fN + 21
MHz
Group Delay
GD
arel
ae = amin
fN
fC
typ. Value
1,9 dB
-
248,6 MHz
6,6 MHz
0,05 dB
Tolerance / Limit
3,5 dB
248,6 MHz
-
5,0 MHz
0,5 dB
... fN – 12
MHz
... fN + 21 MHz
... fN + 251,4 MHz
35-80 dB
18-40 dB
40-60 dB
150
10
ns
ns
min.
min.
min
25
10
25
dB
dB
dB
ns
ns
dBm
max. 300
max. 100
max.
12
Group Delay Ripple
fN ± 120 kHz
Input Power Level
Operating Temperature Range
Storage Temperature Range
Temperature Coefficient
-
-
–36 ppm/K
- 25 °C ... + 75 °C
- 40 °C ... + 85 °C
-
*) The terminating impedances depend on parasitics and q-values of matching elements and the board used, and are to be understood as reference
values only. Should there be additional questions do not hesitate to ask for an application note or contact our design team.
**)
∆f(Hz)
= TCf(ppm/K) x (T-T
0
) x fTo(MHz).
Generated:
Checked / Approved:
Tele Filter GmbH
Potsdamer Straße 18
D 14 513 TELTOW / Germany
Tel: (+49) 3328 4784-0 / Fax: (+49) 3328 4784-30
E-Mail:
tft@telefilter.com
VI TELEFILTER reserves the right to make changes to the product(s) and/or information contained herein without notice. No liability is
assumed as a result of their use or application. No rights under any patent accompany the sale of any such product(s) or information.
VECTRON [ Vectron International, Inc ]
