Compact Ultra Wideband Power Divider with Low Amplitude Imbalance and High Isolation

In this paper an ultra-wideband power divider has been designed, simulated and fabricated. In this structure, the quarter-wave transformer in the conventional Wilkinson power divider, is replaced by an exponentially tapered microstrip line. Since the tapered line provides a consistent impedance transformation across all frequencies, very low amplitude ripple of 0.5dB peak-to-peak in the transmission coefficient and superior input return loss better than 15dB are achieved over an ultra-wide bandwidth. By optimizing the physical locations of the two additional standard resistors added along the tapered line, the output return loss and isolation are improved. The simulation results achieved by full wave analysis based on Finite Element Method (FEM) and the measured results confirm the good performance of the proposed circuit. The return loss of the output ports is better than 15dB and the isolation between the output ports is better than 20dB across the band 6-16GHz. Finally a comparison between ultra-wideband power dividers is provided. It is clear that the proposed divider in terms of the aforementioned important features, has a good performance related to the other ultra-wideband power dividers.