A half-wave dipole antenna is normally fed at the point where:

Antennas are normally fed at points where their impedance closely matches the characteristic impedance of standard transmission lines, such as 50-ohm or 75-ohm coaxial cable. In a half-wave dipole, the center represents the point of maximum current and minimum voltage. According to Ohm's Law (Z = E/I), a low voltage divided by a high current yields a low impedance value. Therefore, feeding the dipole at the center—the point of maximum current—ensures an impedance match suitable for everyday feed lines. Feeding it at a point of maximum voltage (like the ends) would present a very high impedance, requiring a specialized matching network or feedline like ladder line.