The number of sections and the Waveguide size are the
basic parameters that determine the overall length of Round Post-Iris
coupled Microwave Filters.
Using some basic formulas and the wave guide width from
the table above you can calculate the approximate length for a given
Waveguide and number of sections.
From
EXAMPLE #1. We had a Bandpass filter
centered at 10 GHz with 1.0% BW. From the table above we see WR90 is the
best wave guide size for 10GHz. From the same table we see the width of
WR90 is 0.90 inches. Our previous calculations done for example #1
Indicated that we needed 8 sections to meet the required attenuation.
With the number of sections, % BW and Waveguide width we now we have all
the information we need to calculate the approximate length.
N
= number of sections.
a = width of Waveguide in inches
L = Approximate length in inches
For bandwidths 0.3 to 3.0%
L = For 4-8 sections. L= (0.75 x N +
1) a
L = For 9-12 sections. L= (N + 1.0) a
For bandwidths > 3.0% to 7%
L = For 4-8 sections. L= (0.75 x N + 0.667) a
L = For 9-12 sections. L= (0.80 x N + 1.0) a
So for example #1 we have L= (0.75 x 8 + 1) .9 = 6.3 inches
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other types of microwave Filters. Our engineers will help you pick the
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Allen Avionics Inc. started in 1960 And has 49 years
experience in design, Production, quality and they use it on every
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products. |