Wideband polarizer in circular waveguide loaded with dielectric discs

At last year´s Symposium, it was shown that dielectric-disc loading could greatly increase the useful bandwidth of circular waveguide. Figure 1 is a sketch of a circular waveguide containing spaced high-k dielectric discs which strongly load the TE/sub -11/ (dominant) mode, but have little effect on the TM/sub -01/ mode which normally limits the single-mode bandwidth. Figure 2 shows the frequency range over which modes can propagate for disc loading and for uniform loading. Disc loading offers a much greater ratio of single-mode bandwidth, whose upper limit is then determined by the TE /sub -21/ cutoff. This wider frequency band is useful in the design of various components, particularly the polarization converter to be described.