far field

For optimal performance in over-the-air RF systems, antennas must meet specific requirements. Performance parameters like size, wind-loading, environmental ruggedness, transmission pattern, bandwidth, and power handling capability should be considered. Methods of measuring the transmission (or reception) pattern that determines antenna gain with a VNA will be examined in this article.

When it comes to in-situ radiated emission measurements, the combination of near- and far-field measurements is often the best approach.

This article presents the derivation of the far-field criterion for two fundamental wire-type antennas: electric (or Hertzian) dipole and magnetic dipole.

This month's column explains the concept of near and far fields using simple theory and examples.