Compensation of phase errors due to coaxial cable flexure in near-field measurements

Flexure-induced coaxial cable phase variations have long been a major source of error limiting the accuracy of near-field antenna measurements. A method for compensating this cable-flexure-induced phase error that will eliminate much of this error from near field measurements is described. In this method, the reference signal for a phase detector at the probe is brought up to the probe at a much lower frequency than the source signal. At this lower frequency the reference signal is less subject to flexure-induced phase variation. A block diagram of a near-field measurement setup with cable phase error compensation is shown.<>