Design of a novel out-of-phase power divider

A novel two-way out-of-phase power divider（PD）is proposed in this paper. The design principle is similar to conventional Wilkinson structure. By setting the length of the two-output transmission lines properly and introducing an extra line at one end of the isolator, the power divider obtains equal divide, out-of-phase, and good isolation in the passband. Besides, the parameters of the structure are deduced in detail using even-odd mode analysis method. Finally, a power divider, centered at 3.8 GHz，is fabricated to demonstrate the principle by planar microstrip line. It is observed from the measurement that the PD has 1 dB fractional bandwidths of 31%, better than -15 dB return loss and 20 dB isolation, respectively.