Low Cost Hybrid Beamforming Network for 2-D Multi-Beams in Active Phased Array Antenna

This paper presents low-cost hybrid beamforming for simultaneous multiple receive beams, reducing beam-shape loss and enhancing target detection with improved accuracy for 4-D phased array radar. Analog Beam Forming Network (ABFN), being a critical component of the proposed architecture, is described in detail, which generates independent azimuth and elevation channels to form simultaneous multiple beams in azimuth and elevation. Herein, the output of ABFN is further combined using another set of RF manifold to reduce the number of receivers and A/D converters to 99.0% −99.5% of the total number of elements in the radar system. Grating lobe effect in multi-beam configuration, due to more than λ separation between the phase centers of linear subarrays are analyzed and optimized for multi-beam overlap and multi-beam separation. This proposed scheme reduces the cost, complexity and, at the same time, demonstrates the comparable performance of subarray level digital beamforming for multiple receive beams.