How does the feed point impedance of a 1/2 wave dipole change as the feed point is moved from the center toward the ends?
It steadily increases✓Правильный ответ
It steadily decreases
It peaks at about 1/8 wavelength from the end
It is unaffected by the location of the feed point
Объяснение
On a resonant half-wave element the current is maximum at the center and nearly zero at the ends while the voltage does the opposite, and impedance is voltage divided by current, so the impedance rises continuously toward the ends. That is why an end-fed half wave shows thousands of ohms.