An electronic device for converting a frequency with a local oscillator (LO) for generating an LO signal is provided. The electronic device may include an intermediate frequency (IF) port configured to input or output a signal in a first frequency band, a radio frequency (RF) port configured to input or output a signal in a second frequency band, a passive mixer configured to convert the signal in the first frequency band into the signal in the second frequency band or convert the signal in the second frequency band into the signal in the first frequency band, an LO configured to generate an LO signal in one of a plurality of frequency bands and provide the LO signal to the passive mixer, and a bi-directional amplifier including a gain equalizer configured to control gain flatness of a signal input to or output from the IF port.