Provided is a circuit for compensating for the declination of balanced impedance elements and a frequency mixer. The compensation circuit compensates for a difference between impedance measured at first and second impedance elements, and comprises first and second impedance circuits. The first impedance circuit transforms a first impedance value into a fine impedance value having 2n steps in response to n lower bits of a control signal having k bits. The second impedance circuit transforms a second impedance value into a coarse impedance value having 2m steps in response to m upper bits of the control signal. The first and second impedance values are measured at the first and second impedance elements, respectively, and k is equal to m plus n. The impedance difference between the impedance elements is linearly regulated.