Phase Variant CFA Study

The phase length of a crossed-field amplifier (CFA) depends primarily on the dimensions of the anode vanes. CPI/BMD has studied the relationship of individual vane components for a typical CFA, the SFD-262. The vane structure can be reduced to four separate sections, the vane stub, body, tip, and advance. The vane-to-vane capacitance and inductance were modeled analytically to produce phase sensitivity functions. After selecting component dimensions the RF behavior of the vanes is modeled with an electromagnetic code (HFSS). The resulting dispersion relationship was then compared to the dispersion in a series of CFA's that have been constructed. The dispersion relationship was measured on a rotary table.