We report a detailed theoretical study on electron transport through a quan
tum wire connected to the source and drain by flanges. Our results show tha
t the connection flange angle affects significantly the electron transmissi
on through the wire. Resonant reflection and trapping are observed in our c
alculations. The optimal flange angle that allows maximum transmission corr
esponds to this resonance condition, which is around 18 degrees and is esse
ntially independent of the width or length of the wire. This angle changes
by a few degrees when the initial energy, the energy spread of the wave pac
ket, or the length of the flange changes. Stich a finding can be used to as
sist the design of high-conductance quantum wires.