MF Datasheet, PDF (4/5 Pages) Mercury United Electronics Inc – Surface Mount CrystalsSurface Mount Crystals

Legend
K'
Real part of the permittivity (dielectric constant)
tan δ_d Dielectric loss tangent
K" Imaginary part of the permittivity (loss)
M' Real part of the magnetic permeability
tan δ_m Magnetic loss tangent
M" Imaginary part of the magnetic permeability (loss)
dB/cm Attenuation per unit distance
dB/in Attenuation per unit distance
lZl/Z₀ Normalized impedance magnitude ratio
Eccosorb®MF
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 δ_d)
and complex magnetic permeability (M'-jM' Tan δ_m) 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. An
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 δ_m 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 092115
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