Phase compensation technique in a radial divider/combiner structure

The paper presents an efficient technique to compensate for phase dispersion of the elementary power amplifiers in a radial power divider/combiner. A power combiner structure is very sensitive to the phase mismatch between ways which cause degradation of the power combining efficiency. The technique is applied to a 16-way divider/combiner designed for Solid State Power Amplifiers in the K band. The 16-way structure consists of a radial non-resonant cavity connected to 8 peripheral rectangular waveguides with two waveguide-to-microstrip transitions inserted in each peripheral waveguide. Each individual way can be adjusted separately by mechanical sliding of the tray that supports the amplification module. The phase compensation technique was validated with a passive 16-way divider/combiner using trays with different lengths of the microstrip lines to simulate phase mismatch between ways. Finally, a 2-way active module with two combined MMICs has also been tested with 33 dBm output power at 19 GHz.