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Eccosorb®MF

Lossy, Magnetically Loaded, Machinable Stock

LOSSY, MAGNETICALLY LOADED, MACHINABLE STOCK

Eccosorb MF is a series of rigid magnetically loaded epoxy stock, which can be machined

for use as absorbers, attenuators and terminations in waveguides, coaxial or stripline

applications. With products such as these, it is necessary to be conversant with the

dielectric and magnetic properties of the materials, which are listed in this technical

bulletin, the values given are normalized with respect to free space, see Typical Electrical

Properties table.

FEATURES AND BENEFITS

MARKETS



Rigid



Machinable



Commercial Telecom



Security and Defense

SPECIFICATIONS

TYPICAL PROPERTIES

Frequency Range

ECCOSORB MF

>1 GHz

<180 (<356)

1.6 – 4.9

Service Temperature °C (°F)

Density g/cc

Hardness, Shore D

Tensile Strength (MPa)

Thermal Expansion per °C

Water Absorption, % 24 hours

Thermal Conductivity W/mK

~30 x 10

-6

<0.3

1.44

Data for design engineer guidance only. Observed performance varies in application.

Engineers are reminded to test the material in application.

APPLICATIONS



Eccosorb MF is widely used as absorbers, attenuators, and terminations in waveguides

and coaxial lines.



It has also been successfully used as a high-Q inductor-core material in such devices as

slug tuners. It is also useful in many other magnetic components.



Simple RF filters can be formed by passing filament leads through small blocks of

Eccosorb MF, or by casting appropriate sections of the material around such leads by

using one of the electrically equivalent castable absorbers.



There are also applications in antenna elements and in certain free-space absorbers.

For assistance in termination design, see Termination Design Considerations.

Americas: +1.866.928.8181

Europe: +49.(0)8031.2460.0

Asia: +86.755.2714.1166

www.lairdtech.com

Eccosorb®MF

AVAILABILITY



Eccosorb MF is available in the following standard stock sizes :



Sheets 30.5 cm x 30.5 cm (12” x 12”)

in thicknesses of 0.32,

0.64, 0.95, 1.27, 1.59, 1.91,

2.54, 3.81, 5.08, 6.35, 7.62 cm (1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 1.0, 1.5, 2.0, 2.5 & 3.0”).



Rods 30.5 cm long (12”) in diameters of 0.32,

0.64, 0.95, 1.27, 1.59, 1.91, 2.54, 3.81,

5.08, 6.35, 7.62 cm. (1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 1.0, 1.5, 2.0, 2.5 & 3.0” )



Bars 30.5 cm long (12”) in squares of 0.64, 0.95, 1.27, 1.59, 1.91, 2.54, 3.81, 5.08 cm

(1/4, 3/8, 1/2, 5/8, 3/4, 1.0, 1.5 & 2.0”).



Other sizes, shapes, thicknesses, and configurations are available on special order.



In some cases, depending on which Eccosorb MF series is being used, casting of certain

configurations can be done during manufacturing as shown below.

INSTRUCTIONS FOR USE

Termination Design Considerations



The most widely used member of the Eccosorb MF series is MF-117.

It is an excellent

material to start experimentation.

Most designs of terminating and attenuating

elements depend heavily upon cut-and-try procedures.

A preliminary design is

established by experience or rough estimates of probably satisfactory dimensions, a

piece of Eccosorb MF is machined and tested for VSWR and/or attenuation and the

design is then modified as required.



In coaxial, waveguide and strip-line terminations, either step-tapered or uniformly

tapered configurations can be used.



Step-tapered terminations are narrow-banded and highly critical dimensionally.

They

are recommended only where essentially single frequency operation is anticipated.

Increasing the number of steps beyond two can increase the usable band-width and

such designs are helpful when limited length is available in the direction of propagation.

Reproducibility of the performance of step-tapered terminations may be difficult

because of their sensitivity to small changes in magnetic and dielectric properties.



Uniformly tapered terminations are generally preferred because of the low VSWR which

is possible to achieve over a wide frequency range.

Dimensions are reasonably non-

critical and performance is reasonably insensitive to magnetic and dielectric properties.

In general, the more gradual the taper, the lower the VSWR. A length-to-base-width

ratio of 10:1 is highly desirable for VSWR as low as 1.01 over a full waveguide frequency

band, particularly with materials having the higher values of M’ and K’.

A sufficiently

long taper must be used so that very little energy reaches the base mounting plate

where it can be reflected back into the line.

The one-way attenuation should be at least

25 dB for VSWR as low as 1.01.



Wall-type uniform tapers offer maximum heat-transfer efficiency and are recommended

for high-power applications.

RELATED PRODUCTS



For higher temperature applications up to 260 °C, refer to the electrical equivalent

Eccosorb® MF500F.

RFP-DS-MF 061721

ny information furnished by Laird Technologies, Inc. and its agents is believed to be accurate and reliable. All specifications are subject to change without notice. Responsibility for the use and application of Laird Technologies materials rests with the

end user. Laird Technologies makes no warranties as to the fitness, merchantability, suitability or non- infringement of any Laird Technologies materials or products for any specific or general uses. Laird Technologies shall not be liable for incidental or

consequential damages of any kind. All Laird Technologies products are sold pursuant to the Laird Technologies’ Terms and Conditions of sale in effect from time to time, a copy of which will be furnished upon request. © Copyright 2015 Laird

Technologies, Inc. All Rights Reserved. Laird, Laird Technologies, the Laird Technologies Logo, and other marks are trademarks or registered trademarks of Laird Technologies, Inc. or an affiliate company thereof. Other product or service names may be

the property of third parties. Nothing herein provides a license under any Laird Technologies or any third party intellectual property rights.

Eccosorb®MF

TYPICAL ELECTRICAL PROPERTIES

E-M PROPERTIES OF ECCOSORB MF

Frequency GHz

0.1

MF-110

K’

tan δd

K’’

M’

3.9

0.03

0.10

1.3

3.9

0.03

0.10

1.2

3.9

0.03

0.10

1.1

3.9

0.03

0.10

1.1

3.9

0.03

0.10

1.1

3.9

0.03

0.10

1.1

3.9

0.03

0.10

0.40

1.4

tan δm

M’’

dB/cm

|Z|/Z0

MF-112

K’

tan δd

K’’

M’

tan δm

M’’

dB/cm

|Z|/Z0

MF-114

K’

tan δd

K’’

M’

tan δm

M’’

dB/cm

|Z|/Z0

MF-116

K’

tan δd

K’’

M’

tan δm

M’’

dB/cm

|Z|/Z0

MF-117

K’

tan δd

K’’

M’

tan δm

M’’

dB/cm

|Z|/Z0

MF-124

K’

tan δd

K’’

M’

tan δm

M’’

0.2

0.3

0.1

227

0.1

0.2

215

0.1

0.7

208

0.1

1.4

204

0.1

2.4

203

0.1

3.8

201

0.1

5.2

199

0.1

6.5

197

5.4

0.1

0.4

2.1

0.0

0.1

233

5.3

0.0

0.1

1.9

0.2

0.4

0.6

226

5.3

0.0

0.1

1.4

0.3

0.4

2.1

198

5.3

0.0

0.1

1.2

0.2

2.9

184

5.3

0.0

0.1

1.2

0.2

3.2

181

5.2

0.0

0.1

1.2

0.1

3.4

180

5.2

0.0

0.1

1.2

0.1

3.6

179

5.2

0.0

0.1

1.2

0.1

3.7

179

8.4

0.1

2.7

0.1

0.3

0.1

214

7.9

0.0

0.1

2.2

0.3

0.7

3.6

202

7.9

0.0

0.1

1.7

0.5

0.8

9.2

182

7.9

0.0

0.1

1.4

0.5

0.7

13.3

167

7.9

0.0

0.1

1.2

0.5

0.6

15.9

157

7.9

0.0

0.1

1.2

0.4

0.5

17.7

151

7.8

0.0

0.1

1.1

0.4

18.9

147

0.0

0.1

2.7

0.1

0.3

0.6

214

14.3

0.0

0.1

3.6

0.0

0.1

191

0.0

0.1

3.6

0.1

0.4

0.8

190

0.0

0.1

0.3

0.9

5.3

179

0.0

0.1

2.4

0.4

0.9

11.8

161

0.0

0.1

2.1

0.4

0.8

15.7

151

0.0

0.1

0.3

0.6

17.9

144

0.0

0.1

1.9

0.3

0.5

19.1

141

0.0

0.1

1.8

0.2

0.4

19.9

139

16.9

0.0

0.3

5.5

0.1

0.3

0.1

215

16.7

0.0

0.1

4.2

0.3

1.4

2.5

193

16.7

0.0

0.1

3.2

0.4

1.3

8.1

172

16.7

0.0

0.1

2.6

0.6

1.6

20.6

161

16.7

0.0

0.1

0.9

1.7

36.7

149

16.7

0.0

0.1

1.5

1.1

1.6

16.7

0.0

0.1

1.2

1.4

63.3

123

16.7

0.0

0.1

1.1

68.8

111

136

21.6

0.0

0.3

5.6

0.0

0.1

192

0.1

1.3

5.4

0.2

19.1

0.0

0.7

0.6

2.2

13.6

185

18.9

0.0

0.5

2.5

0.9

2.2

31.1

157

18.9

0.0

0.4

1.8

0.9

1.7

43.5

137

18.9

0.0

0.4

1.5

0.9

1.4

51.9

124

18.9

0.0

0.4

1.3

0.9

1.2

57.9

115

18.9

0.0

0.4

1.2

0.8

dB/cm

|Z|/Z0

MF-175

K’

tan δd

K’’

M’

tan δm

M’’

dB/cm

|Z|/Z0

MF-190

K’

2.5

197

62.2

109

31.3

0.0

0.5

5.1

0.0

0.1

28.7

0.1

2.9

4.9

0.2

0.8

2.9

157

26.2

0.1

1.9

3.9

0.5

1.8

14.5

153

25.7

0.0

1.2

2.6

0.7

1.8

25.5

0.0

25.4

0.0

0.8

1.7

0.7

1.2

25.3

0.0

0.8

1.6

0.6

25.2

0.0

0.7

1.5

0.6

0.9

0.8

1.5

103

153

133

119

109

34.1

0.0

0.8

5.7

0.0

0.1

154

30.5

0.1

3.8

5.5

0.2

27.3

0.1

2.4

4.2

0.5

2.1

26.7

0.1

1.4

2.7

0.8

2.2

26.6

0.0

1.1

0.9

1.8

26.5

0.0

0.9

1.7

0.9

1.5

26.4

0.0

0.8

1.5

0.8

1.2

26.3

0.0

0.8

1.4

0.7

tan δd

K’’

M’

tan δm

M’’

dB/cm

|Z|/Z0

3.6

161

157

136

120

110

102

RFP-DS-MF 061721

the property of third parties. Nothing herein provides a license under any Laird Technologies or any third party intellectual property rights.

Eccosorb®MF

Legend

K’

Real part of the permittivity (dielectric constant)

tan δ

Dielectric loss tangent

K”

Imaginary part of the permittivity (loss)

Real part of the magnetic permeability

M’

tan δ

Magnetic loss tangent

M”

Imaginary part of the magnetic permeability (loss)

dB/cm Attenuation

per unit distance

dB/in Attenuation

per unit distance

lZl/Z

Normalized impedance magnitude ratio

Most of the definitions and equations are included in the Laird publication :”

ENERGY PROPAGATION IN DIELECTRIC AND MAGNETIC

MATERIALS

.” A copy of this publication can be requested.

In this technical bulletin, μ’ is used for the real part of the magnetic permeability and μ” for the magnetic loss factor. Beyond the definitions in

the publication above, the clarification of the terms dB/cm (attenuation) and |Z|/Zo (relative impedance) are offered.

These characteristics are not in themselves directly applicable to the calculation of transmission and reflection coefficients as they are defined

on point 3 & 4 of “Energy Propagation in Dielectric and Magnetic Material”. For these calculations, the complex dielectric constant (K’-jK’ Tan



)

and complex magnetic permeability (M’-jM’ Tan



) are used as listed in the table.

The definition of dB/unit length is included in the reference, both in mathematical form and in words. The value is useful in comparing one

material against another to determine which offers the most loss independent of interface reflection coefficients. Similarly, |Z|/Zo, the

normalized impedance magnitude ratio, can be used as a qualitative measure of the impedance match between free space and the material.

impedance ratio that is closest to 1 is the most desirable because at that ratio, the impedance match between the material and free space is

perfect.

The significant features of the property tables are:

1. In every case, K’ decreases with increasing frequency.

2 Almost without exception, the dielectric loss tangent and dielectric loss factor decrease with increasing frequency, the exception occurs at the

low end of the frequency band, and can be ignored in most applications.

3.The magnetic loading increases from a minimum in MF-110 to a maximum in MF-190. There is a corresponding increase in K’, K”, μ’, Tan



and

μ”.

4.The 0 values in the table indicate that the number is less than 0.01.

5.The values given in the table are nominal values and should not be used by customers in the writing of procurement specifications.

If specifications are needed, the customer should consult with the Laird Sales Department.

The use of dielectric/magnetic properties for Quality Control, i.e., incoming or outgoing inspection, is not recommended, because the

measurement of these properties is very time consuming and complicated.

It is recommended to monitor the density.

RFP-DS-MF 061721

the property of third parties. Nothing herein provides a license under any Laird Technologies or any third party intellectual property rights.

Eccosorb®MF

MACHINING RECOMMENDATIONS

Most of the discussion below applies not only to the basic Eccosorb MF series of materials, but also to several high temperatures, castable and

molding-powder equivalents. Eccosorb MF can be formed readily to close tolerances with standard metal-working machine tools, i.e.: lathes,

milling machines, drills, saws, grinders, generally using conventional techniques but observing the precautions and limitations described below.

Tooling :



For turning, milling, drilling and tapping, carbide tools should be used, for example Type 883, a general purpose carbide that works

well under most conditions. Use solid carbide taps for long life.

Standard size tap drills should be satisfactory.

External threads are formed best, not with conventional thread-cutting dies but by lathe turning or grinding, with light feeds and

shallow cuts.

Sawing can be done with best finish and tolerance using circular saws, 20.3 to 25.4 cm diameter, with grinding coolant and high RPM.

Thin carborandum wheels, 0,079 cm thick or carbide saws may be used where requirements are less stringent.

Best results are

attained by moving the saw and keeping work stationary, with saw rotating so it tends to climb into the work.

Surface finishing of flat sheets, etc. is best performed with a Blanchard grinder.

Eccosorb MF is held readily with magnetic chucks.

Sheet size is limited by the size of the machine.



Coolants :



Use of a coolant liquid is recommended, especially for all close tolerance operations. Commercial grinding fluid is preferred, or water-

soluble oil, with rust-resisting properties to protect the machines. Spark producing operations in particular must not be run dry, since

smoldering fires might result.



Where coolant run-off is collected for recirculation, a two-cavity recovery system should be used to minimize pick-up of grinding dust,

sawdust or chips by the coolant pump.

Where a re-circulating system is not available, best results will be obtained with air-powered

spray or mist equipment.

Use of tapped metal inserts should be considered where electrical performance will not be degraded.

Inserts may be cast in place, or bonded

with castable material of suitable composition.

Suggested Speeds and Feed Rates

The following speeds and feed rates are suggested to be modified as necessary to suit job conditions:

OPERATION

Sawing, turning

SPEED

FEED

21.3 – 27.4 m/min

(70-90 ft/min)

0.13 – 0.20 mm

.005-.008 in/revolution

External threading

21.3 – 27.4 m/min

70-90 ft/minute

0.038 mm/pass

.001 in/pass

Tapping

Milling

450 rpm

Tapping Head

21.3 – 27.4 m/min.

70-90 ft/min

0.038 – 0.076 mm/tooth

.0015-.003 in/tooth

RFP-DS-MF 061721

the property of third parties. Nothing herein provides a license under any Laird Technologies or any third party intellectual property rights.

Laird-Signal-Laird-Tech-24048378

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