 Waveguide Bandpass Filters
ALLEN AVIONICS SINGLE AND DOUBLE IRISCOUPLED Waveguide Bandpass
Filters are available over the 1.12 to 26.50 GHz frequency band.(WR-650
to WR-42) In the ICMB Series Bandwidths may be as small as 0.3% to as
large as 3.0% of the center frequency. These filters are available with
5 to 12 "high Q" resonant sections and offer an Lower Cost solution to
many Microwave filtering applications. Allen Avionics Waveguide Filters
are normally constructed using rectangular Brass Waveguide but Copper,
Aluminum and Invar are also available. All Waveguide filters are
available with additional options like cover flanges, choke flanges or
with coaxial transitions to SMA and other
connectors. |
| Available
Frequency |
1.12 GHz –
26.5 GHz |
| Available
Bandwidth |
0.3% Up to
3% |
| Insertion
Loss |
(Depends on
the number of sections and Bandwith) |
| Stop Band
Attenuation |
see graphs |
| Number of
Resonator Sections Available |
4 to 12 |
| VSWR |
1.50:1 |
| Standard
W/G Sizes |
WR650 to
WR42 |
| Dimensions |
See
drawings below.
Consult Factory for exact dimensions. |
|
|
CONNECTOR CODE CHART |
|
FEMALE ("N") |
FN |
|
MALE ("N") |
MN |
|
FEMALE SMA
|
FS |
|
MALE SMA |
MS |
|
2.4 mm FEMALE |
24F |
|
2.4 mm MALE |
24M |
|
CPR FLANGE |
CPR |
|
CPRG FLANGE |
CPRG |
|
CMR FLANGE |
CMR |
|
COVER FLANGE |
CF |
|
CHOKE FLANGE |
CH |
|
|
|
The curves to the right display The Relative
Attenuation as a Function of the Normalized 3dB Bandwidth for
IrisCoupled Bandpass filters (3.0%). The graphs are designed to
give an approximation of the frequency response for the ICWB
series of Waveguide filters. Using these curves and a few simple
formulas shown below you can predict the attenuation for a given
number of sections. Curves for narrow bandwidths (0.3%) and
medium bandwidths (3.0%) are also provided. There are many
variables that affect the Frequency Response Attenuation and
Insertion loss of Waveguide filters so when exact information is
required contact the factory at (516) 248-8080 or send email to
sales@allenavionics.com
|
 |
 |
 |
The Frequency response curves we supply
show the approximate attenuation as a function of the
normalized 3dB bandwidth. Using these graphs we can
calculate attenuation at a given frequency for a
specified number of sections or determine the number of
sections required to meet a set of given attenuation
points.
EXAMPLE #1 (Find required # of sections)
We want a Bandpass filter centered at
10.0 GHz (FO) with a 3dB bandwidth of 100 MHz (FC). We
have a stopband requirement of 60dB at 9.70GHz and
10.30GHz.
First we need to determine the
percentage bandwidth (%BW) using the following formula
to find the correct graph to use.
 |
With a 1% bandwidth the graph for .3% would give
us the best approximation. Now we have two stopband
requirements. The low side 60db attenuation point is 9.70GHz and
the high side is at 10.30GHz. Now we need to calculate the
number of 3dB bandwidths using the following formula.
Checking the above graph we can see that about 8
sections will have over 60dB attenuation at both stopband
requirements.
EXAMPLE #2 (Find
minimum attenuation at specified frequencies)
We want a Bandpass filter centered
at 2.50 GHz (FO) with a 3dB bandwidth of 10 MHz (FC) and we are
thinking about using 6 sections. We need to find the minimum
attenuation at 2.460GHz and 2.540GHz for 6 sections.
Using the same formula above we first find the %Bw
to determine the correct graph to use. In this problem the the
%BW equals 0.4% so we can use the 0.3%bw graph again. Then from
the second formula we used in the first example we find that we
have four (4) 3dB bandwidths on each side.
Checking the above graph we can see with 6
sections we will have greater than 50dB attenuation at both
2.460GHz and 2.540GHz for a filter with 10MHz 3dB bandwidth. Two
plots are provided, 0.3%, and 3.0% so the approximate response
can be determined for any bandwidth in the range of 0.3% to
3.0%.
When bandwidths exceed the 3.0% limit for this
filter type or when insertion loss, length rejection required or
some other parameter cannot be met, Allen Avionics has many
other Filter constructions available which could be used to
solve the problem. Contact our sales department for assistance
at (516) 248-8080 or send email to
sales@allenavionics.com
|
|
 |
Allen Avionics has advanced simulation and
modeling software that our experienced Microwave engineers use
in the design and manufacturing of Iris Coupled Wave Guide
Bandpass Filters. This software combined with our Numerical
Control Machining Center gives us rapid design and production
capabilities. Allen Avionics has the ability to manufacture
prototypes and short runs quickly and reduce lead times on large
production runs.
Our Microwave and Mechanical engineers are
always available to help with custom designs or applications.
The sales force at Allen Avionics is ready to help with
information and prices. They try to answer all quotes in 48
hours or less and are familiar with all our microwave products.
All of these products are manufactured in the USA using only
American made material. |
|
| WR |
U.S. Mil.
__ /U |
FL— FU
GHz |
Inside
Width (a)
(in) |
|
WR650 |
RG69
(b)
RG103 (a) |
1.12-1.70 |
6.500 |
|
WR510 |
|
1.45-2.20 |
5.100 |
|
WR430 |
RG104 (b)
RG105 (a) |
1.70-2.60 |
4.300 |
|
WR340 |
RG112
(b)
RG113 (a) |
2.20-3.30 |
3.400 |
|
WR284 |
RG48
(b)
RG75 (a) |
2.60-3.95 |
2.840 |
|
WR229 |
RG340 (c)
RG341 (a) |
3.30-4.90 |
2.290 |
|
WR187 |
RG49 (b)
RG95
(a) |
3.95-5.85 |
1.872 |
|
WR159 |
RG343 (c)
RG344
(a) |
4.90-7.05 |
1.590 |
|
WR137 |
RG50
(b)
RG106 (a) |
5.850-8.200 |
1.372 |
|
WR112 |
RG51
(b)
RG68 (a) |
7.050-10.000 |
1.122 |
| WR90 |
RG52
(b)
RG67 (a) |
8.20-12.40 |
0.900 |
| WR75
|
RG346 (c)
RG347 (a) |
10.0-15.0 |
0.750 |
| WR62
|
RG91 (b)
RG349 (a) |
12.40-18.00 |
0.622 |
| WR51 |
RG352 (c)
RG351 (a) |
15.00-22.00 |
0.510 |
| WR42 |
RG53
(b)
RG121 (a) |
18.00-26.5
|
0.420 |
|
MODEL DESIGNATION
| Code |
Description |
| 1 |
Series |
| 2 |
Number of Sections |
| 3 |
Center Frequency (GHz) |
| 4 |
3 dB Bandwidth (MHz) |
| 5 |
Connector Code(Input/Output)
(see chart) |
| 6 |
WR Waveguide number |
|
| 1 |
2 |
3 |
4 |
5 |
6 |
| ICMB/ |
5/ |
20.25/ |
101.25/ |
CPR/CPR/ |
42 |
COMPLETE Part Number =
ICMB / 5 / 20.25 / 101.25 / CPR / CPR / 42
Contact Factory With Your Specific Needs
For:
-Electrical Performance
-Mechanical Configuration
-Insertion Loss
|
MATERIAL
When bandwidths exceed the 7.0% limit for this
filter type or when insertion loss, length rejection required or
some other parameter cannot be met, Allen Avionics has many
other Filter constructions available which could be used to
solve the problem. Contact our sales department for assistance.
(516) 248-8080 or
sales@allenavionics.com |
|
|
The number of sections and the Waveguide size are the
basic parameters that determine the overall length of IrisCoupled
Microwave Filters.
Using some basic formulas and the wave guide width from
the table 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 calculations done for example #1 Indicated that
we needed 8 sections to meet the required attenuation. With the number
of sections 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 + 0.667) a
L = For 9-12 sections. L= (0.8 X N + 1.0) a
So for example #1 we have
L= (0.75 x 8 + 0.667) .9 = 6.0
inches
ALLEN AVIONICS INC manufactures many other types of
microwave Filters. Our engineers will help you pick the right filter to
meet all the requirements you have for performance, size and cost. Our
advanced simulation and modeling software will design and do
optimization of Circular Post Coupled filters, Metal-Insert Filters,
Iris Coupled Filters, Combline and Interdigital Filters All of our
Filters can be custom designed for
 your application
and we offer fast prototypes. No need to wait five or six weeks to test
your idea or check your system.
Allen Avionics Inc. started in 1960 And has 49 years
experience in design, Production, quality and they use it on every
product they make. Check out the Allen Avionics web site for all their
products. |
