A “UWB” half-wavelength dipole for low-frequency gain reference

Antenna power gain measurements are frequently done using a gain-transfer method outlined in IEEE standards. This requires the use of a reference antenna with a known gain in order to reference the antenna under test. However, the conventional approach of gain calibration ultra-wideband (more than 10:1) below 200 MHz could be very tedious and not reliable using a set of half-wavelength dipoles commercially available. Such a calibration procedure requires manually switching different baluns for each subband and adjusting physical lengths of the dipole for each balun.