Radial line mode converter

A radial line mode converter is developed, which can convert TEM (or TM01) mode to TE11 mode by changing the azimuthal symmetry of field distribution in wavequide. The principle of the mode converter is as follows: the coaxial TEM mode is converted to 4-way 90°-sector-waveguide TE11 mode by setting fins into the coaxial waveguide; the output phase differences among the sector waveguides are realized by transforming the sector waveguide to two-layered radial line. A mode converter centered at 1.6 GHz based on this principle is designed and optimized. The calculated results show that it has high power handling capacity, with about 10% bandwidth (1.52 to 1.68 GHz) where the conversion efficiency exceeds 90% and the conversion efficiency and reflection are 99% and 0.05 respectively at the cen