A novel dielectric waveguide intensity modulator configuration is described. The intensity modulation can be achieved at a potentially wide bandwidth with lumped-type electrodes, by taking advantage of a combination of the conventional mode-extinction effect and a novel branching effect. The modulation performance is analyzed numerically. It is found that by using the proposed configuration, the bandwidth of the conventional mode-extinction modulator is almost doubled. The proposed configuration may also be used as a switch, although not in the usual manner.