Modelling and design of a finite dual-polarised notch phased-array antenna

The authors present the modelling and design procedure for a finite dual-polarised notch phased-array antenna which has a triangular lattice to obtain a widescan ability in the azimuth and elevation planes. The array antenna has orthogonal linear polarisations for transmitting and receiving, and the triangular element grid is achieved by 45° rotation of a square grid of notch elements in egg-crate configuration. A numerical waveguide simulator for the H-plane scan is modelled to eliminate scan blindness in the H-plane. A numerical model for the finite dual-polarised notch array is built to investigate the convergence of the active-element pattern (AEP) and the effects of the grating lobe according to array size. To verify the numerical results, a wideband active phased-array system was fabricated which consists of a 10×12×2 notch array, 8×8 transmit/receive modules and beam-forming networks. The scan patterns measured by near-field measurement show good agreement with the converged AEP for the finite array model and have widescan performance in the azimuth and elevation planes.