An electronic device includes a feedback oscillator configured to output a first oscillation signal and a second oscillation signal, the second oscillation signal having a defined phase difference from the first oscillation signal, the feedback oscillator including a phase shifter configured to receive the first oscillation signal and output the second oscillation signal, an up-conversion mixer configured to output a first loopback signal obtained by mixing the first oscillation signal with a reference tone signal, and output a second loopback signal obtained by mixing the second oscillation signal with the reference tone signal, and a receiver configured to generate a first reference IQ signal from the first loopback signal, generate a second reference IQ signal from the second loopback signal, and compare an actual phase difference between the first reference IQ signal and the second reference IQ signal with the defined phase difference.