On the Minimum Range Length for Performing Accurate Direct Far-Field Over-the-Air Measurements

Integrated-Antenna Over-the-Air Testing for Millimeter-Wave Applications: An Overview of Systems and Uncertainty [Measurements Corner]

“…This contributes to additional uncertainty for the radiation pattern measurement of the main beam (EIRP and EIS). For example, for a 72-mm DUT operating at 43.5 GHz measured with 50-cm distances, an error of approximately 1.25 dB is added, which mostly affects the second lobes [16]. The measurement of TRP with this method also deviates in roughly the same order [16].…”

“…For example, the characterization of an mm-wave active phasedarray antenna is performed in an anechoic chamber with a planar scanner, as discussed in [14]. In [15] and [16], an FF measurement, which is used to evaluate the RF parameter of an array antenna, is performed with minimum distance inside a compact chamber. In [17], an mm-wave device with an antenna array is measured using the compact antenna test range (CATR) technique.…”

“…To reduce the measurement distance of the DFF system, the principle of Fraunhofer distance is revisited in [16] and [50]. A different criterion of the FF region, that of observing the antenna's directivity, is used, rather than the device's dimension.…”

“…By implementing this criterion, DFF measurements are conducted in a much shorter distance if only the peak beam region is analyzed, rather than the full radiation pattern. For a 15-cm DUT at 43 GHz, the measurement distance can be reduced from 6.5 (Fraunhofer distance) to 1.74 m [16].…”

Radiation Pattern Verification of Active Antenna Systems Using Near-Field Measurements

“…Furthermore, the phase error should be less than π/ 8 radians (or 22.5°within the quiet zone range) to meet the minimum requirements for the far-field condition [5]. Because the wavelength of a millimeter-wave is very short, large antenna apertures are usually needed.…”