A Novel 3D Flower-Shape Dual Circular-Polarized Antenna Array for Ultra-Wideband Monopulse Scan

A 3D flower-shape ultra-wideband antenna array, with performance of dual circular-polarized, for the monopulse application of tracking radar has been designed and tested. The array, constructed by eight vivaldi-shape antennas, has a stable wide beam of sum-and-difference patterns on working band and gain of 10.5 dB. The sum and difference patterns can be obtained by out-phase excitations of the eight coaxial ports. The measurement results demonstrate that the working bandwidth of the proposed antenna array is up to 170%. The simulation result shows that, the 3-dB beamwidth of the sum pattern both for the E plane and H plane is more than 30° over the working bandwidth, and the null depths of the difference pattern are below -30 dB in both planes.