Cutoff Variable Reactor (Correspondence)

When relatively high positive reactance is required for coaxial line circuits, the cutoff variable reactor can economize space. In Fig. 1, a schematic diagram of the cutoff variable reactor is shown. For z<0, there is the coaxial line; and for z>0, there is the cylindrical waveguide operated in cutoff region with the variable shorting plunger shorting the waveguide at the distance s. For simplicity, it is assumed that there is TEM mode alone on the coaxial line and TM₀₁ mode alone in the waveguide.