The π-shift sinusoidal signals with different amplitudes applied directly to the two metallic finger gates on a shallow etched GaAs/AlGaAs quantum wire，tune unequally the two barriers of a static quantum dot induced by applying negative dc voltages on these two finger gates. Single electrons are transported through a periodically formed quantum dot without source-drain bias. Since single electron pumping in the novel semiconductor-based quantum dot device does not rely on Coulomb blockade of tunnelling，the device can not be limited to much lower frequency by the fixed tunneling time constant. Current plateaus due to single electron transport can be observed at 1.7K with frequencies up to 3GHz and a current level of 0.5nA. This novel device represents another possible path in the realization of a high current high accuracy quantum standard for electrical current，and also provides another means for high specd high accuracy transport of single electrons.