Abstract— This work investigates the improvement of the active reflection coefficient of waveguide-fed phased-array antenna using liquid crystal layers. The anisotropy properties of liquid crystal layer can be employed to eliminate blind scan angle and improve the wide angle impedance matching of the waveguide-fed phased array antennas. The authors have expressed the modal analysis of the waveg...

Calibrating dual polarization in phased array radars is an important aspect of risk mitigation in moving towards a nationwide multifunctional phased array radar (MPAR) system for weather surveillance and to track aviation. Since dual polarization was implemented into the WSR-88D, the new products have been vital for hydrometeor classification. The calibration of scan-dependent polarization in p...

multiple input multiple output (mimo) radars are new generation of array radars that employ orthogonal waveforms for their transmit probing signals. despite of several advantages, this strategy results in transmission of uniform power in all angle of array’s viewing field. therefore, possibility of transmit beamforming and achieving coherent processing gain will be lost. many efforts have been ...

Phased arrays have long been used by the military for radar applications, but have only been recently applied to consumer applications. In a phased array system, one or more narrow beams are generated by transmitting (or receiving) a common RF signal that is phase shifted at the output of each antenna in the array such that the direction of the beams can be varied by controlling the phase diffe...

Recently, the number of unusual extreme weather that causes natural disasters is increasing, and accompanying phenomena such as local heavy rainstorms, tornado, and gust fronts have caused an immediate and often devastating impact on a broad range of human activities. Weather radar has played an important role to survey those meteorological phenomena associated with rainfall and to mitigate mos...