Calibration and validation of the CASA phased array antenna

This paper describes the calibration and validation of one-dimension scanned phased array antenna for an X-band weather radar being developed at the Engineering Research Center for the Collaborative Adaptive Sensing of the Atmosphere (CASA). The antenna aperture is based on a linear array of vertical subarrays. Each subarray is fed by a separate Transmit/Receive (T/R) module which provides phase, amplitude and polarization diversity. The characterization and calibration of the array are based on single element measurements obtained from a portable near-field probe test system. The calibration is validated by measuring the antenna radiation pattern in a near-field antenna range. In addition, thermal stability tests are performed to estimate the system performance loss.