Low-Pass

4-Pole

Appendix A

Bessel

2

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Normalized Frequency(f/fc)

Normalized Time (1/f sec)

Normalized Time (1/f sec)

Frequency Response

Delay

(Normalized)

Step Response

0.1

1.0

10.0

2

3 4 5 6 78

2

3 4 5 6 7

-100

-80

-60

-40

-20

0

0.1

1.0

2

3

4

5 6 7 8 9

0.0

0.5

1.0

1.5

0.15

0

1

2

3

4

5

-0.0

-0.2

0.2

0.4

0.6

0.8

1.0

1.2

(sec)

Theoretical Transfer Characteristics

1

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.85

0.90

0.95

1.00

1.10

1.20

1.30

1.40

1.50

1.60

1.70

1.80

1.90

2.00

2.25

2.50

2.75

3.00

3.25

3.50

4.00

5.00

6.00

7.00

8.00

9.00

10.0

1.Normalized Group Delay:

The above delay data is normalized to a corner frequency

of 1.0Hz.The actual delay is the normalized delay divided

by the actual corner frequency (fc).

Actual Delay =

Normalized Delay

Actual Corner Frequency (fc) in Hz

f/fc

(Hz)

Amp

(dB)

Phase

(deg)

Delay

0.00

-12.1

-24.2

-36.3

-48.4

-60.6

-48.1

-53.4

-58.0

-62.0

-65.7

-25.1

-27.6

-30.0

-34.4

-41.9

-12.2

-13.4

-16.5

-19.5

-22.4

-6.37

-7.42

-8.54

-9.71

-10.9

-2.69

-3.01

-3.71

-4.51

-5.39

-1.02

-1.41

-1.86

-2.11

-2.40

0.00

-0.028

-0.111

-0.251

-0.448

-0.705

-315

-321

-326

-330

-333

-267

-275

-281

-291

-305

-212

-219

-235

-248

-259

-166

-177

-187

-195

-204

-115

-121

-133

-144

-156

-72.7

-84.8

-96.8

-103

-109

.021

.016

.012

.009

.008

.089

.076

.065

.049

.031

.211

.194

.158

.129

.107

.295

.280

.263

.246

.228

.332

.330

.325

.318

.308

.336

.336

.335

.334

.333

.336

.336

.336

.336

.336

.336