Analysis of the helical twisted-wire pair running above ground:transfer function evaluation

Surface wave transmission line theory for single and many wire systems

“…The right-hand side of (26) contains the magnetic flux through S m . As in the single wire case, the surface wave on conductor m will contribute LI m to this flux where L is the self-inductance derived in (9). However, the presence of other surface waves can now contribute to the overall magnetic flux through the surface S m as well.…”

“…7 Shielded and unshielded twisted pairs as well as more complicated binder cables have been examined with this method. 6,[8][9][10] However, modes that so far are disregarded by MTL may start affecting propagation with increasing frequency. In particular, surface waves that are fundamental modes of single wires have been disregarded as their lateral size is extremely large for low frequencies.…”

“…Such nonuniform cables can, for instance, be modeled through the concatenation of short, uniform segments. 9 Finally, non-uniform cables may also show mode conversion to the surface wave mode (see the supplementary material), which can only be modeled with the newly proposed theory. This includes the conversion from the differential mode (DM) to the surface wave mode making our theory more accurate for the simulation of realistic cables in DSL scenarios.…”