Disclosed herewith is a broadband wireless repeater for a mobile communication system. The broadband wireless repeater generally includes a transmission stage and a receiving stage. The transmission stage includes an RF switch for establishing a frequency path, an Intermediate Frequency delay unit for applying delay to IFs and bypassing the IF delay, a frequency up conversion modulator, an amplifier, a filter unit for eliminating undesired band signals, and a transmitting side antenna. The receiving stage includes an array antenna, a band-pass filter unit for eliminating undesired band signals, an amplifier, a phase shifter for controlling phases of channels, a frequency down conversion modulator, a phase comparison unit, a gain comparison unit, a vector value optimizer for decreasing errors of the main signals with a maximum output, and a synthesizing module for detecting and storing output levels of the channels.