Which of the following conductors is preferred for bonding at RF?

The preferred conductor for bonding at RF applications is flat copper strap. This choice is ideal primarily due to its ability to provide a low-resistance connection, which is crucial for minimizing RF noise and ensuring efficient grounding. The flat shape increases the surface area in contact with the bonding points, enhancing conductivity and reducing inductance, which is particularly significant at RF frequencies.

Using a flat copper strap helps in maintaining effective grounding by offering a better connection surface compared to round or twisted forms of conductors. This characteristic is essential when dealing with high-frequency signals, as any impedance in the bonding can lead to RF interference or signal degradation.

Other options, such as copper braid removed from coaxial cable, are less effective because they do not provide the same level of surface contact and can have higher resistance and inductance compared to flat copper strap. Steel wire is less preferable due to its higher resistivity and potential rust problems, which can affect performance. Twisted-pair cable is designed for data transmission and isn’t suited for grounding or bonding applications needed for effective RF operation, focusing instead on differential signaling rather than conductivity.