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CUMING MICROWAVE - A
Global Supplier of Microwave Absorbing Materials, Radar Absorbers,
Dielectric Materials, Anechoic Chambers, EMC Chambers for the Defense,
Electronic, Telecom, Medical and Automotive Industries.
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Very High
Performance Pyramidal Absorber
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C-RAM SFC HP
VERY HIGH PERFORMANCE BROADBAND RF ABSORBER
PYRAMIDAL
120 MHz - 50 GHz

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C-RAM SFC-HP is a series of very high performance broadband
RF absorbers made from specially treated low density polyurethane foam. The
product is flexible and tolerant of physical abuse. Using a very steep
pyramid design which provides an impedance gradient, C-RAM SFC-HP provides
improved premium performance in anechoic chambers at both normal and
off-normal incidence angles. These products meet all of the fire retardancy
requirements of NRL Specification 8093 tests 1, 2, and 3, MS-8-21 tests 1,
2, and 3, and T.I. drawing 2693066, as well as ASTM E-84-97a, Class A.

Optional Clean Room Coating (CRC) Meets Class 100,000 (ISO 8)
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PHYSICAL CHARACTERISTICS
AND TYPICAL REFLECTIVITY AT NORMAL INCIDENCE (SFC-HP) |
Model |
Height
in. (mm) |
Weight
lbs. (kg) |
Tips
Per Piece |
Reflectivity in dB at
Frequency (GHz) |
0.1 |
0.3 |
0.5 |
1.0 |
3.0 |
6.0 |
10 |
18 |
36* |
50* |
SFC-8HP |
9 (228) |
4.5 (2.0) |
100 |
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9 |
18 |
31 |
39 |
45 |
50 |
55 |
55 |
55 |
SFC-12HP |
14 (356) |
6 (2.7) |
64 |
4 |
15 |
29 |
35 |
42 |
45 |
50 |
55 |
55 |
55 |
SFC-18HP |
20 (508) |
8 (3.6) |
25 |
9 |
30 |
35 |
40 |
45 |
50 |
52 |
55 |
55 |
55 |
SFC-24HP |
26 (660) |
11 (5) |
16 |
12 |
34 |
39 |
44 |
50 |
50 |
55 |
55 |
55 |
55 |
SFC-36HP |
36 (914) |
16 (7.2) |
9 |
18 |
35 |
40 |
45 |
51 |
52 |
55 |
55 |
55 |
55 |
Notes: *
SFC-HP has been characterized at 36 and 50 GHz, but is not
routinely measured at these frequencies. |
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High
Performance Pyramidal & Walkway Absorber
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C-RAM SFC
HIGH PERFORMANCE BROADBAND RF ABSORBER
PYRAMIDAL
120 MHz - 50 GHz


Optional Clean
Room Coating (CRC) Meets Class 100,000 (ISO 8)
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C-RAM SFC is a series of high performance broadband RF
absorbers made from specially treated low density polyurethane foam. The
product is flexible and tolerant of physical abuse. Using a steep pyramid
design which provides an impedance gradient, C-RAM SFC provides premium
performance in anechoic chambers at both normal and off-normal incidence
angles.
These products meet all of the fire retardancy requirements of NRL
Specification 8093 tests 1, 2, and 3, MS-8-21 tests 1, 2, and 3, and T.I.
drawing 2693066, as well as ASTM E-84-97a, Class A


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C-RAM SFC-ODP
HIGH PERFORMANCE BROADBAND RF ABSORBER
FOR OUTDOOR USE
PYRAMIDAL
(Outdoor)
120 MHz - 50 GHz

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C-RAM ODP is a series of very
high performance absorbers similar to C-RAM EVA.
C-RAM ODP is made from a lightweight open cell foam with large pores. This
large pore size allows rain water to drain readily and dry
quickly after rain stops. The RF lossy coating is not affected by repeated
exposure to rain.
C-RAM ODP is dimensionally equivalent to the corresponding grades of C-RAM
SFC. The reflectivity characteristics are identical to those
of C-RAM SFC.
C-RAM ODP is a very resilient material. It stands up well to moderate
physical abuse and tolerates repeated deformations without tear or
cracks.
C-RAM ODP is processed using a fire retardant saturant, however it does not
meet the NRL 8093 test #1, 2 and 3 for fire retardancy.
Consequently the product is not recommended for indoor usage.

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C-RAM SFC-WW
HIGH PERFORMANCE BROADBAND RF ABSORBER
WALKWAY


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C-RAM SFC-WALKWAY is a series of high performance broadband RF absorbers, fabricated from standard C-RAM SFC pyramidal absorber. The SFC
absorber is fit with a low density polystyrene foam matching section to
square the piece off, and the sides and top of the block are fit with a half
inch (13mm) thick sheeting of fire retardant polyvinyl chloride (PVC) rigid
foam.
Walkway absorber provides an effective access path for
servicing the transmit and receive areas of an anechoic chamber.
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C-RAM SFC PYRAMIDAL & WALKWAY PHYSICAL
CHARACTERISTICS TYPICAL REFLECTIVITY AT NORMAL INCIDENCE (dB) |
Model |
Absorber Height
in. (mm) |
Walkway
Overall Height
in. |
Weight
lbs. (kg)
Walkway (2.5 x below) |
Tips /
Piece |
Absorption (dB)
at Freq. (GHz) |
.08 |
.12 |
.3 |
.5 |
1 |
3 |
6 |
10 |
18 |
*36 |
*50 |
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SFC-3
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3.0 (76)
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6.3
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2.9 (1.3)
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256
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26 |
32 |
39 |
45 |
50 |
50 |
SFC-4 |
4.3 (109) |
7.3 |
3.0 (1.4) |
144 |
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30 |
35 |
42 |
50 |
50 |
50 |
SFC-6 |
6.0 (152) |
9.0 |
3.5 (1.6) |
100 |
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32 |
40 |
45 |
50 |
50 |
50 |
SFC-8 |
8.0 (203) |
11.0 |
4.5 (2.0) |
64 |
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30 |
37 |
45 |
50 |
50 |
50 |
50 |
SFC-12 |
12.0 (305) |
15.0 |
6.0 (2.7) |
36 |
|
3 |
13 |
27 |
35 |
40 |
45 |
50 |
50 |
50 |
50 |
SFC-18 |
18.0 (457) |
21.0 |
12.0 (5.4) |
16 |
|
6 |
26 |
30 |
37 |
40 |
45 |
50 |
50 |
50 |
50 |
SFC-24 |
24.0 (610) |
27.0 |
17.0 (7.7) |
9 |
7 |
9 |
30 |
35 |
40 |
45 |
50 |
50 |
50 |
50 |
50 |
SFC-36 |
36.0 (914) |
39.0 |
24.0 (10.9) |
4 |
9 |
15 |
35 |
37 |
42 |
50 |
50 |
50 |
50 |
50 |
50 |
SFC-40 |
40.0 (1016) |
43.0 |
39.0 (18) |
4 |
11 |
16 |
35 |
38 |
43 |
50 |
50 |
50 |
50 |
50 |
50 |
SFC-48** |
48.0 (1219) |
51.0 |
38.0 (17) |
2 |
14 |
21 |
35 |
40 |
50 |
50 |
50 |
50 |
50 |
50 |
50 |
SFC-72** |
72.0 (1829) |
75.0 |
50.0 (23) |
1 |
26 |
28 |
38 |
45 |
50 |
50 |
50 |
50 |
50 |
50 |
50 |
SFC-96 |
96.0 (2438)
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99.0
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58 (26.5)
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1 |
28 |
32 |
40 |
44 |
50 |
50 |
50 |
50 |
50 |
50 |
50 |
* SFC has been characterized at 36 and 50 GHz, but is not routinely measured
at these frequencies.
** SFC-48 and -72 are generally supplied in the "twisted" configuration.
The base of the SFC-48 is 18 x 36" (457 x 914 mm).
The SFC-72 has the
standard 24" (610 mm) base.
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Absorber
Operational Temperature Range: -40° C to +120° C (adhesives or coatings may
reduce the range)

Reflectivity performance
of a walkway is degraded from that of the SFC
absorber comprising it, due to reflections from the PVC skin. The
degradation becomes more significant with increasing frequency; below 1GHz,
the degradation is small, at 10 GHz, reflectivity is limited to about 25 dB,
in mm-wave applications, other methods of accessing equipment should be
considered, such as removing and replacing absorber before beginning
testing.
C-RAM SFC WALKWAY can be made from any grade of the standard
SFC absorber, but SFC-24 is the largest standard size. Pieces are generally
24 in x 48 in (610 x 1220 mm), or 24 in x 24 in (610 x 610 mm). Other custom
sizes can be made, as well as steps, ramps, and cutouts for pedestals.
TYPICAL REFLECTIVITY
(BISTATIC) AT OFF-NORMAL INCIDENCE (Multiply numbers in
chart by dB values in tables above) |
Absorber Height in
Wavelengths |
Off-normal angle (0°
= normal, 90°
= grazing) |
45° |
50° |
55° |
60° |
65° |
70° |
75° |
80° |
4.0 |
1.00 |
0.95 |
0.86 |
0.75 |
0.70 |
0.60 |
0.51 |
0.43 |
2.0 |
0.90 |
0.82 |
0.74 |
0.66 |
0.58 |
0.49 |
0.42 |
0.34 |
1.0 |
0.72 |
0.65 |
0.58 |
0.50 |
0.44 |
0.37 |
0.31 |
0.25 |
0.5 |
0.48 |
0.43 |
0.37 |
0.31 |
0.25 |
0.20 |
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High
Performance Wedge Absorber
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C-RAM SFC-W
HIGH PERFORMANCE RF ABSORBER
WEDGE SHAPED
500 MHz - 50 GHz

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C-RAM SFC-WEDGE is a series of high performance broadband absorbing materials of wedge configuration. SFC-WEDGE complements the
pyramidal SFC product, and is made using the same process and materials. SFC-WEDGE
therefore possesses the same desirable properties, including fire retardancy
compliance with NRL-8093 Tests 1, 2 and 3.
C-RAM SFC-WEDGE is
designed for use in special applications where energy is directed at very
wide angles, as in the case of energy propagation down the taper of a
tapered chamber, and on chamber side walls, ceiling and floor in very long
and narrow chambers. The wedge design eliminates backscatter at these high
incidence angles.
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PHYSICAL CHARACTERISTICS
AND TYPICAL REFLECTIVITY AT NORMAL INCIDENCE (SFC-WEDGE) |
Model |
Height
in. |
Weight
lbs. |
Wedge
Rows
Per Piece |
Reflectivity in dB at
Frequency (GHz) |
0.1 |
0.3 |
0.5 |
1.0 |
3.0 |
6.0 |
10 |
18 |
36 |
50 |
SFC-4W |
4 |
5 |
12 |
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27 |
32 |
37 |
45 |
45 |
45 |
SFC-6W |
6 |
8 |
10 |
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30 |
37 |
40 |
45 |
45 |
45 |
SFC-8W |
8 |
10 |
8 |
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30 |
35 |
45 |
47 |
47 |
47 |
47 |
SFC-12W |
12 |
13 |
6 |
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35 |
37 |
45 |
47 |
47 |
47 |
47 |
SFC-18W |
18 |
16 |
4 |
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30 |
35 |
45 |
47 |
47 |
47 |
47 |
47 |
SFC-24HP |
24 |
22 |
3 |
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30 |
35 |
40 |
45 |
48 |
50 |
50 |
50 |
50 |
SFC-36W |
36 |
30 |
2 |
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35 |
38 |
42 |
45 |
48 |
50 |
50 |
50 |
50 |
SFC-48W |
48 |
45 |
2 |
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35 |
40 |
46 |
48 |
50 |
50 |
50 |
50 |
50 |
Notes:
SFC-W Standard Base Dimensions are 24" x 48", 24" x 24"
also available |
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Convoluted Microwave Absorber
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C-RAM FAC
HIGH PERFORMANCE
BROADBAND
MICROWAVE ABSORBER
CONVOLUTED
3 GHz - 77 GHz
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C-RAM FAC is a series of high performance broadband microwave absorbers, made from light weight, very flexible urethane foam treated with a dielectric lossy material, which also imparts great fire retardancy. The product meets NRL 8093.
C-RAM FAC is a convoluted product; the front face is rippled or convoluted like an egg carton, the convolutions provide an impedance taper, which is very effective in minimizing front face reflections, especially at higher frequencies.
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TYPICAL DIMENSIONS
REFLECTIVITY PERFORMANCE in dB (SFC-FAC) |
Model |
Height in. (mm) |
Weight lb. (kg) |
3GHz |
6GHz |
10GHz |
15GHz |
30GHz |
77GHz |
FAC 1.5 |
1.5 (38) |
1 (0.45) |
- |
20 |
30 |
35 |
40 |
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FAC 3.0 |
3.0 (64) |
1.8 (0.82) |
20 |
30 |
40 |
45 |
50 |
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FAC 4.0 |
4.0 (102) |
2.3 (1.1) |
25 |
30 |
40 |
45 |
50 |
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Outdoor Convoluted Microwave Absorber
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C-RAM RFA (Outdoor)
HIGH PERFORMANCE
BROADBAND
MICROWAVE ABSORBER
CONVOLUTED
2 GHz - 50 GHz

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C-RAM RFA is a similar convoluted absorber available in
various thickness grades. It is made from a large-pore open-cell
urethane foam (approx 15 pores/inch). This open cell structure makes
C-RAM RFA ideal for outdoor applications, where rain can drain
quickly through the piece, and residual moisture can evaporate
quickly. For optimum resistance to moisture, C-RAM RFA uses a
different fire retardancy mechanism. While it is self-extinguishing,
this material is not rated to NRL 8093 standards.
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TYPICAL DIMENSIONS
REFLECTIVITY PERFORMANCE in dB (SFC-RFA) |
Model |
Height in. (mm) |
Weight lb. (kg) |
2GHz |
5GHz |
10GHz |
15GHz |
20GHz |
50GHz |
RFA 075 |
0.75 (19) |
0.5 (.25) |
- |
12 |
15 |
17 |
18 |
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RFA 175 |
1.75 (45) |
0.8 (.35) |
12 |
18 |
25 |
28 |
30 |
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RFA 375 |
3.75 (95) |
1.5 (.70) |
25 |
32 |
37 |
40 |
40 |
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