Broad-Band Impedance Matching into Dielectric-Filled Waveguides

The problem of impedance matching between two waveguides filled with different dielectrics is discussed, and the conditions for broad-band matching are determined. Experimental results are presented for standard waveguides matched to guides filled with dielectrics having permittivities ε as high as 100_epsi0. Present applications include matching devices for X-band coupled-cavity transmission masers which employ ruby and alumina sections (ε ≈ 10_epsi0) . Future applications include matching devices for masers utilizing rutile (ε as high as 250/subε0/).