Common Base Amplifier

The input goes into the emitter, the base is AC-grounded, the output comes from the collector. Gain $\approx g_m R_C$ (non-inverting), input impedance only about $r_e$.

Because the base shields the input from the output, the Miller effect is avoided, so common-base stages are used at RF and in the cascode configuration (common-emitter + common-base) to combine high gain with wide bandwidth.