An interpolation technique for time-domain phased array measurements

A technique is presented for determining the insertion phase of phased array elements from time-domain spectra. It is shown that the inverse discrete Fourier transform (IDFT), commonly used in obtaining a time-domain spectrum, yields unreliable phase results. A phase compensation to the IDFT is proposed which allows the phase of an array element to be accurately determined without explicit time-gating and without taking a second DFT. The technique is applied to determine the element insertion phases of an L-band array.