A Miniaturized Wideband Symmetric 3x3 Nolen Matrix with Phase Compensation Technique

In the paper, a miniaturized wideband symmetric 3x3 Nolen matrix with phase compensation technique is presented. By adjusting the phase slope through three pairs of differential phase shifters, the flatness of the output ports phase differences is improved. Besides, size reduction is obtained by using trans-directional couplers. Based on the designed equations, a prototype operating at 5.8 GHz is fabricated and measured. The fractional bandwidths (FBWs) for more than 10 dB return loss and isolation are 31.21 % and 45.17 %, respectively. Under the criterions of 1-dB amplitude imbalance and 5 degrees phase derivation error, the measured FBWs are more than 20.86% and 16.03%, separately.