  We construct a matter-wave beam splitter using 87Rb Bose-Einstein condensate
on an atom chip. Through the use of radio-frequency-induced double-well
potentials, we were able to split a BEC into two clouds separated by distances
ranging from 2.8 {\mu}m to 57 {\mu}m. Interference between these two freely
expanding BECs has been observed. By varying the rf-field amplitude, frequency,
or polarization, we investigate behaviors of the beam-splitter. From the
perspective of practical use, our BEC manipulation system is suitable for
application to interferometry since it is compact and the repetition rate is
high due to the anodic bonded atom chip on the vacuum cell. The portable system
occupies a volume of 0.5 m3 and operates at a repetition rate as high as ~0.2
Hz.
