A 5.5GHz Band 2-D Beamforming Network Using Broadside Coupled Stripline Structure

In this paper, a novel planar and compact 2-D Beamforming Network (BFN) designed in Broadside coupled stripline structure for a 2x2 planar patch array antenna is proposed at 5. 5GHz. The 2-D BFN is composed of four broadside 3dB/90
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stripline couplers interconnected by short transmission lines. The designed and fabricated 2-D BFN in Multilayer Rogers substrate achieves broadband characteristic over 3.7-6.8GHz frequency band in terms of impedance match, transmission amplitude, and phase responses.