A novel optical controlled beam forming network (OCBFN) scheme based on broad band optical source and dispersion device is presented and compared with traditional scheme based on laser diode (LD). The principle of this scheme is illustrated by theoretical analysis and the feasibility is validated by experiment. In experiment, Er-doped fiber amplifier (EDFA) is used as broad band optical source, 10 km single mode fiber (SMF) is used as dispersion device for time delay, tuneable optical filter is used to choose operation wavelength, and vector network analyzer is used to generate microwave signal and measure the time delay performance. In 9.25～10.25 GHz microwave band, system time delay range, time delay precision and true time delay performance are measured, and the feasibility of the OCBFN scheme based on broad band optical source is verified by the experiment results.