900CT Datasheet, PDF (15/19 Pages) Frequency Devices, Inc. – Tunable Active Filter Instrument

8-Pole, 6-Zero
Appendix A
Elliptic, 1.77
Low-Pass
Theoretical Transfer Characteristics
Frequency Response
f/fc
Amp Phase Delay1
(Hz) (dB) (deg) (sec)
0.00 0.00
0.00 0.713
0.10 -0.004 -25.7 0.716
0.20 -0.014 -51.6 _0.724
0.30 -0.024 -77.9 _0.740
0.40 -0.020 -105 _0.767
0.50 0.007 -133 0.811
0.55 0.022 -148 0.840
0.60 0.033 -163 0.872
0.65 0.031 -179 0.908
0.70 0.014 -196 0.946
0.75 -0.015 -213
0.80 -0.041 -232
0.85 -0.046 -251
0.90 -0.016 -272
0.95 -0.025 -296
0.989
1.04
1.12
1.23
1.40
0
-20
-40
-60
-80
-100
0.1
2 3 4 5 6 78 _1.0 2 3 4 5 6 7 _10.0
Normalized Frequency(f/fc)
Delay (Normalized)
1.00 -0.035 -323 1.65
4.0
1.10 -1.76 -392 2.14
1.20 -8.28 -467 1.86
1.30 -18.4 -522 1.19
1.40 -29.3 -558 0.753
1.50 -40.1
1.60 -51.5
-578
-594
0.517
0.381
2.0
1.70 -65.2 -606 0.296
1.75 -75.0 -611 0.265
1.80 -113.0 -616 0.239
0.8
1.85 -83.6
1.90 -82.0
1.95 -83.7
2.00 -87.8
2.20 -85.8
-440
-444
-447
-450
-280
0.217
0.198
0.182
0.168
0.126
0.0
0.1 ^{0.15 2}
3 4 5 6 7 8 9_1.0 1.5
Normalized Time (1/f sec)
2.40 -82.0
2.60 -83.5
2.80 -88.2
3.00 -99.9
3.50 -87.2
4.00 -83.1
5.00 -82.1
6.00 -83.1
7.00 -84.6
-289
-295
-301
-305
-134
-140
-148
-154
-157
0.099
0.081
0.067
0.057
0.040
0.030
0.018
0.013
0.009
Step Response
1.2
1.0
0.8
0.6
8.00 -86.2 -160 0.007
0.4
9.00 -87.8 -163 0.005
10.0 -89.3 -164 0.004
0.2
1.Normalized Group Delay:
-0.0
The above delay data is normalized to a corner frequency
of 1.0Hz.The actual delay is the normalized delay divided
0
1
2
3
4
5
by the actual corner frequency (fc).
Normalized Time (1/f sec)
Normalized Delay
Actual Delay =
Actual Corner Frequency (fc) in Hz
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