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Future weather radar systems will need to provide rapid updates within a flexible multifunctional overall radar network. This naturally leads to the use of electronically scanned phased array antennas. However, the traditional multifaced planar antenna approaches suffer from having radiation patterns that are variant in both beam shape and polarization as a function of electronic scan angle; even with practically challenging angle-dependent polarization correction, this places limitations on how accurately weather can be measured. A cylindrical array with commutated beams, on the other hand, can theoretically provide patterns that are invariant with respect to azimuth scanning with very pure polarizations. This paper summarizes recent measurements of the cylindrical polarimetric phased array radar demonstrator, a system designed to explore the benefits and limitations of a cylindrical array approach to these future weather radar applications.

This work describes the concept and current development of a novel automated system to characterize active phased array antennas. The proposed system, called an RF Scanner, has been conceptualized and developed by the Advanced Radar Research Center (ARRC) at the University of Oklahoma (OU). This system enables the full characterization of electromagnetic, surface, and thermal properties of an active phased array antenna. An industrial 6-axis articulated robot is used to move a sensor suite to perform near-field measurements as well as surface and thermal inspection of the antenna under test (AUT). The sensor suite consists of a mechanical fixture supporting an infrared camera, a high-precision laser, a high-definition camera, and an antenna array probe. The AUT, the robotic manipulator, and the sensor suite are located inside of an environmental chamber. This environmental chamber enables characterization of the AUT under controlled temperature and humidity. The combination of the high precision robot, sensor suite, environmental chamber, and vector network analyzer (VNA), along with a software interface, allows fully automated characterization of an active phased array antenna from 1 GHz to 18 GHz, up to 60 GHz if the VNA is upgraded, over a temperature range of 0° C to 50 ° C.

This paper describes the design of a mobile Cylindrical Polarimetric Phased Array Radar (CPPAR) developed at the Advanced Radar Research Center (ARRC). The primary purpose of the radar is to prove the concept of a CPPAR and demonstrate its inherent polarimetric advantages. Since these advantages become most apparent in the context of the polarimetric weather radar mission, the ability to make meaningful weather measurements with the system is desired. With limited resources, a novel system has been designed which both can demonstrate the CPPAR concept and serve as a platform for general phased array research in the future.