An Improved Holographic Technique for Medium-Gain Antenna near Field Measurements

A modification of the holographic technique based on synthetic plane wave for determining radiation patterns and aperture fields of medium-gain horn antennas is proposed. The modification is based on using both the sum and difference of the near field and reference signals to form the hologram via simple low-cost amplitude-only near field measurements. This approach when compared to the previous version, where only the sum signal is used, allows increased sample spacing, and also provides an improvement in quality of the final results. The effectiveness of the modified technique is confirmed by both calculated and measured results obtained for a conical horn antenna operating at 10 GHz frequency.