Amplitude-balanced and broadband quadrature hybrid for radar and LTE applications

Amplitude balanced two-section quadrature hybrid using a microstrip lines is proposed. The proposed microstrip quadrature hybrid with unequally reduced impedances compared to the original values of longitudinal and transverse branches was optimized using HFSS simulations. Two-section microstrip line hybrid has measured bandwidth of 34%, good amplitude balance of ± 0.35 dB, good reflection and isolation of 18 dB, and phase imbalance of 2° in the range of frequencies from 2.7 GHz to 3.8 GHz. The measured data of the proposed two-section hybrid is good consistent with HFSS simulations.