Planar Out-of-Phase Power Divider/Combiner for Wideband High Power Microwave Applications

The design of an out-of-phase planar power divider/combiner operating over an octave frequency band is presented. The proposed device uses a modified single-section Gysel structure. The main features of the proposed device are simple and easy to package structure that does not use any slots in the ground plane, and the use of one isolation resistor that can be external to the packaging structure for efficient heat dissipation. The proposed device is suitable for high-power microwave modules and perfectly compatible with microstrip circuits. A complete design method is derived and validated. To make the device compact without jeopardizing its power capacity, a moderate meandering for the utilized transmission lines using an elliptical function is adopted. To compensate for the parasitic elements introduced in one of the signal paths due to meandering, the transmission line at the other path is elliptically tapered. The simulated and measured results of the developed device show one octave bandwidth with 180° ± 9° differential phase between the output ports and of isolation. The final design has a compact area of of the squared guided wavelength.