What is the recommended bend radius for coaxial cable when routing from an antenna to a receiver?

What is the recommended bend radius for coaxial cable when routing from an antenna to a receiver?

• A. 5 times the diameter
• B. 20 times the diameter
• C. 10 times the diameter
• D. 2 times the diameter

Answer: (C)

Bend radius matters because bending a coaxial transmission line changes the impedance and can cause losses and reflections if the bend is too tight. A sharply curved path disturbs the electric field around the inner conductor and the shield, leading to impedance mismatches, microbending losses, and potential detuning of the connected antenna. Using a bend radius about ten times the cable’s outer diameter keeps the field distribution close to that of a straight run, minimizing impedance changes and additional loss. This conservative rule helps maintain signal integrity from the antenna to the receiver. Tighter bends (like only a couple of times the diameter) increase the risk of reflections and detuning, while a much larger bend is more about extra space than a different principle. So, the recommended practice is a bend radius of roughly ten times the cable diameter.

Bend radius matters because bending a coaxial transmission line changes the impedance and can cause losses and reflections if the bend is too tight. A sharply curved path disturbs the electric field around the inner conductor and the shield, leading to impedance mismatches, microbending losses, and potential detuning of the connected antenna.

Using a bend radius about ten times the cable’s outer diameter keeps the field distribution close to that of a straight run, minimizing impedance changes and additional loss. This conservative rule helps maintain signal integrity from the antenna to the receiver. Tighter bends (like only a couple of times the diameter) increase the risk of reflections and detuning, while a much larger bend is more about extra space than a different principle.

So, the recommended practice is a bend radius of roughly ten times the cable diameter.