VIDEO LOWPASS FILTERS
SERIES ATLW Stopband Ratio @45dB = 1.32
ATCL Stopband Ratio @45dB = 1.14
ATBW Stopband Ratio @45dB = 1.08
ABW Stopband Ratio @42dB = 1.066
For many years amplitude, Delay and phase corrected filters have found applications in
Television Broadcasting, Cable transmission, Direct Satellite Transmission, Analog and
Digital Image Processing, Analog to Digital conversion and Computer Graphics. Allen
Avionics offers four basic shape factors or stopband ratios in their range of Video
Filters.
ATLW General purpose filters include
amplitude,Phase and Group Delay
equalization to improve pulse and bar
response. Smooth slower roll off reduces
ringing. Can be used as in any Video
bandwidth limiting application. Also used
as anti aliasing pre filters in analog to
digital conversion applications or as post
aliasing filters with the addition of sin x/x
correction.
ATCL More complex filter for applications
requiring a sharper cutoff rate. The tight
control of amplitude, phase and delay of
the ATCL series makes them ideal for
high performance analog and digital
applications.
ATBW Almost a Brickwall Filter. The
ATBW is a good compromise for
sharpness, ringing, insertion loss and
cost. The ATBW stopband ratio of 1.08 is
close to the ABW series Brickwall ratio of
1.066 but has less ringing, Delay
distortion and insertion loss.
ABW A true Brickwall Filter. The ABW
series is the sharpest cutoff Video filter
available anywhere. Tight control of the
Amplitude, Phase and Delay
Characteristics create a filter unmatched
for sharpness, low ringing, insertion loss
and cost. Typical NTSC applications use
this filter to pass 4.20MHz and reject
everything above 4.48MHz which
requires a stopband ratio of 1.066. See
Brickwall data sheet.
Basic ATLW Specifications PERFORMANCE
Passband Flatness: Ripple Less than
+/-.1dB
Insertion Loss @ 100KHz =1.0dB Max
Impedance =75 Ohms unbalanced
Return Loss = -20dB typical
Group Delay Ripple less than +/- 2% of
midband delay
Stopband Attenuation = 45dB Min
Stopband Ratio = 1.32@-45dB
Temperature Range Operating -20 to +65
Degrees Celsius
KEY
Fp Frequency at which amplitude ripple
exceeds Ap (peak to peak ripple)
Fs Frequency at which stopband
attenuation exceeds As
F3dB Nominal Frequency at which
attenuation is 3dB
Pd Nominal Propagation delay through filter
in Nanoseconds
Gd Typical passband group delay ripple,
Nanoseconds peak-to-peak
FGd Frequency at which group delay ripple
limits is exceeded, MHz
Ap Peak-to-peak passband ripple, dB
As Minimum stopband attenuation, dB
ATLW PART
NUMBER
Fp MHz
Ap <
.2db
F3dB
MHz Fs,
MHz As
>45dB
Gd,
ns FGd
MHz Pd
ns
ATLW0P46
0.46 0.52 0.61 220
0.44 5500
ATLW0P93
0.93 1.03 1.22 110
0.89 2750
ATLW1P40
1.40 1.55 1.85 75
1.33 1833
ATLW1P87
1.87 2.06 2.47 55
1.78 1375
ATLW2P34
2.34 2.58 3.09 45
2.22 1100
ATLW2P57
2.57 2.84 3.40 40
2.45 1000
ATLW2P80
2.80 3.09 3.70 37
2.67 917
ATLW2P92
2.92 3.22 3.86 36
2.77 881
ATLW3P27
3.27 3.61 4.32 32
3.11 786
ATLW3P74
3.74 4.12 4.94 28
3.56 688
ATLW3P97
3.97 4.38 5.25 26
3.78 647
ATLW4P03
4.03 4.44 5.32 25
3.83 638
ATLW4P21
4.21 4.64 5.56 25
4.00 611
ATLW4P68
4.68 5.15 6.18 25
4.45 550
ATLW4P91
4.91 5.41 6.48 21
4.67 524
ATLW5P15
5.15 5.67 6.80 20
4.90 500
ATLW5P43
5.43 5.98 7.17 19
5.16 474
ATLW5P61
5.61 6.19 7.40 18
5.34 458
ATLW6P08
6.08 6.70 8.03 17
5.79 423
ATLW6P55
6.55 7.22 8.65 16
6.23 393
ATLW7P02
7.02 7.73 9.27 15
6.68 367
ATLW7P49
7.49 8.25 9.89 14
7.12 344
ATLW7P95
7.95 8.76 10.50 13
7.57 324
ATLW8P42
8.42 9.28 11.12 12
8.01 306
ATLW8P89
8.89 9.79 11.74 12
8.46 289
ATLW9P36
9.36 10.31 12.36 12
8.90 275
Basic ATCL Specifications PERFORMANCE
Passband Flatness: Ripple Less than +/-.1dB
Insertion Loss @ 100KHz =2.5dB Max
Impedance =75 Ohms unbalanced
Return Loss = -20dB typical
Group Delay Ripple less than +/- 1.5% of midband
delay
Stopband Attenuation = 45dB Min
Stopband Ratio = 1.14@-45dB
Temperature Range Operating 0 to +50 Degrees
Celsius
ATCL PART
NUMBER
Fp MHz
Ap <
.2db
Fs,
MHz As
>45dB
Gd,
ns FGd
MHz Pd
ns
ATCL0P46
0.46 0.53 265
0.43 8846
ATCL0P93
0.93 1.06 134
0.86 4466
ATCL1P40
1.40 1.60 89
1.30 2967
ATCL1P87
1.87 2.13 67
1.73 2233
ATCL2P34
2.34 2.66 53
2.17 1782
ATCL2P57
2.57 2.92 49
2.39 1619
ATCL2P80
2.80 3.19 45
2.60 1488
ATCL2P92
2.92 3.32 43
2.71 1428
ATCL3P27
3.27 3.72 38
3.04 1275
ATCL3P74
3.74 4.26 33
3.48 1114
ATCL3P97
3.97 4.52 32
3.69 1050
ATCL4P03
4.03 4.59 31
3.75 1035
ATCL4P21
4.21 4.80 30
3.91 990
ATCL4P68
4.68 5.34 27
4.35 890
ATCL4P91
4.91 5.59 25
4.57 849
ATCL5P15
5.15 5.87 24
4.79 810
ATCL5P43
5.43 6.19 23
5.05 768
ATCL5P61
5.61 6.39 22
5.22 743
ATCL6P08
6.08 6.94 21
5.65 686
ATCL6P55
6.55 7.47 19
6.09 637
ATCL7P02
7.02 8.00 18
6.52 594
ATCL7P49
7.49 8.54 17
6.96 557
ATCL7P95
7.95 9.07 16
7.40 524
ATCL8P42
8.42 9.60 15
7.83 495
ATCL8P89
8.89 10.13 14
8.26 468
ATCL9P36
9.36 10.67 13
8.70 445
Basic ATBW Specifications PERFORMANCE
Passband Flatness: Ripple Less than +/-.1dB
Insertion Loss @ 100KHz =4dB Max
Impedance =75 Ohms unbalanced
Return Loss = -20dB typical
Group Delay Ripple less than +/- 1.25% of midband
delay
Stopband Attenuation = 45dB Min
Stopband Ratio = 1.08@-45dB
Temperature Range Operating 0 to +50 Degrees
Celsius
ATBW PART
NUMBER
Fp MHz
Ap <
.2db
Fs,
MHz As
>45dB
Gd,
ns FGd
MHz Pd
ns
ATBW0P46
0.46 0.49 265
0.42 10612
ATBW0P93
0.93 1.00 140
0.86 5591
ATBW1P40
1.40 1.52 93
1.30 3710
ATBW1P87
1.87 2.02 70
1.72 2780
ATBW2P34
2.34 2.53 56
2.16 2222
ATBW2P57
2.57 2.78 51
2.37 2023
ATBW2P80
2.80 3.03 47
2.59 1857
ATBW2P92
2.92 3.15 45
2.70 1780
ATBW3P27
3.27 3.54 40
3.02 1590
ATBW3P74
3.74 4.04 35
3.45 1390
ATBW3P97
3.97 4.29 33
3.67 1310
ATBW4P03
4.03 4.35 33
3.72 1290
ATBW4P21
4.21 5.63 31
3.89 1235
ATBW4P68
4.68 5.05 28
4.32 1111
ATBW4P91
4.91 6.54 27
4.54 1059
ATBW5P15
5.15 5.56 26
4.76 1010
ATBW5P43
5.43 5.87 24
5.02 957
ATBW5P61
5.61 6.05 23
5.18 926
ATBW6P08
6.08 6.56 21
5.62 855
ATBW6P55
6.55 7.08 20
6.05 793
ATBW7P02
7.02 7.59 19
6.49 740
ATBW7P49
7.49 8.09 18
7.92 694
ATBW7P95
7.95 8.59 17
7.35 654
ATBW8P42
8.42 9.10 16
8.78 617
ATBW8P89
8.89 9.60 15
8.22 584
ATBW9P36
9.36 10.11 14
8.65 555
