Extension of Single-Cut NFFFT to Multi-Cut Fresnel- Field FFT Depending on Antenna Height

We propose an extension of a single-cut near-field far-field transformation (SCNFFFT) to a multi-cut Fresnel-field far-field transformation (MCFFFFT) depending on the height of an antenna under test. The new transformation is a natural extension of the SCNFFFT proposed in [1] and makes it possible to measure the single-cut plane pattern for an antenna with the height of many wavelengths, whose patten cannot be obtained by the SCNFFFT. Using our cylindrical near-field measurement system composed of an EO probe and a lock-in amplifier, that does not need a vector network analyzer [2], we demonstrate that the MCFFFFT gives the correct patterns of a horn antenna with 23 dBi at 76.2 GHz when the antenna is rotated around the boresight direction and the SCNFFFT cannot be applied, in simulations and measurements.