Determining Uncertainty in Antenna Array Measurements

Recently a 7X7 cross dipole array** was built and tested to compare its performance against the predicted calculations which were obtained using the Numerical Electromagnetic Code, version 4 (NEC-4). The cross dipole array was designed to operate at two bands: the lower band ranged from 56 MHz to 140 MHz and the upper band ranged from 130 MHz to 200 MHz. A vector network analyzer (Hewlett Packard 875 1 A), contr_plled by a PC compatible machine over the GPIB interface, was used to characterize the array and some of its subarrays (e.g., 3X3, 2X2, etc.). Over 1500 measurements were made.