What is the feed point impedance of an end-fed half-wave antenna?

At the ends of a resonant half-wave antenna wire, the RF voltage is at its absolute maximum, while the RF current is at its minimum. According to Ohm's Law for AC circuits (Impedance = Voltage / Current), feeding an antenna at a high-voltage, low-current point results in a very high impedance. The feed point impedance of an end-fed half-wave (EFHW) antenna is typically between 2000 and 5000 ohms. This requires a specialized matching network (like a 49:1 or 64:1 unun) to step the impedance down to the 50 ohms expected by modern transceivers. In contrast, feeding a half-wave dipole exactly in the center targets the point of maximum current and minimum voltage, resulting in a low feed point impedance of roughly 50 to 73 ohms.