A phase-arrayed device includes: a signal processing circuit arranged to generate a specific signal; a first phase-arrayed channel arranged to provide a first phase-arrayed signal according to the specific signal; a first conducting path arranged to conduct the specific signal to the first phase-arrayed channel; a second conducting path arranged to conduct the first phase-arrayed signal to the signal processing circuit; and a detecting circuit, arranged to detect a mismatch between the first phase-arrayed signal and a reference signal to generate a detecting signal utilized for calibrating the first phase-arrayed signal.