Which of the following would increase the bandwidth of a Yagi antenna?
Larger-diameter elements✓Correct answer
Closer element spacing
Loading coils in series with the element
Tapered-diameter elements
Explanation
A larger-diameter element has a lower length-to-diameter ratio and therefore lower Q, so its reactance changes more slowly with frequency and the usable SWR bandwidth widens. Loading coils do the opposite, raising Q and narrowing bandwidth.