For a practical device, a low crosstalk level
must be ensured.
9 represents the distribution of values of the dielectric relative permittivity [[epsilon].sub.r] contributing to extreme crosstalk levels of [absolute value of ([H.sub.1])].
Extreme crosstalk levels of [absolute value of ([H.sub.1])] (a) obtained by the sparse PC metamodel, at 202 MHz.
(a) Extreme crosstalk levels of [absolute value of ([H.sub.1])] obtained by the sparse PC metamodel, at 2.23 GHz.
The overall shield, by design, brings those alien crosstalk levels
to virtually zero.
If we change a stackup to achieve the impedance requirement, then the crosstalk levels also change.
If the dielectric material (thickness) is changed in the stackup, then the crosstalk levels between the traces change too.
While category 6A UTP cables can perform adequately with respect to alien crosstalk in an ideal installation or test environment, real-world installation practices and subsequent moves, adds and changes can deform UTP cable geometry causing increased alien crosstalk levels
. This occurs because UTP cables rely upon the physical separation of pairs in adjacent cables provided by flexible and easily-compressed dielectric materials to control alien crosstalk.