Half-Wave Dipole

Center-fed half-wave dipole antenna at 300 MHz. The wavelength is close to 1 meter, so the dipole length equals 0.5 meters. 

The standard donut-shaped radiation pattern is obtained having a maximum dimensionless gain of 1.65, which is very close to the theoretical value of 1.64, which is the gain of an infinitely thin wire half-wavelength long.

The effect of the finite wire radius can also be seen in the input impedance. The obtained radiation resistance (real part of input impedance) equals 91 Ohm, which is greater than the theoretical value of 73 Ohm for the infinitely thin dipole.

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