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The category 7a connector ARJ45 (augmented RJ45) does not have any split

pairs. An alternative category 7a connector that was not derived from the RJ45

interface is described by ISO 61076-3-114.

Figure 2. Category 7a to 6a plugs combined in a single patch cord

Compensation vs. Isolation

The Major Difference between Category 7a and Lesser Categories.

The major difference between RJ45 and ARJ45 connectors and interfaces is how

the differential Near End Cross Talk is attenuated. That issue was one of the

prime factors why the International Standards Organization decided to change to

a new interface for applications above 500 MHz in the IEC/ISO standard

60603-7-7.

The RJ45 connector categories 5e to 6a use compensation to cancel the

differential NEXT. The compensation is a method of purposefully creating the

crosstalk in the near vicinity of the interface that is equal in amplitude but

opposite in phase to the NEXT “native” to the interface. In practice, it calls for

adding capacitive and some inductive elements and creating complex structures

within the connectors. The compensation in the RJ45 connectors is used in both:

shielded and unshielded designs.

The category 7a connectors rely on isolation to attenuate the NEXT. Category 7a

connectors are always shielded. A Faraday cage is built around each differential

pair that isolates them from each other, thus reducing NEXT. The ARJ45

Category 7a

Category 6a