A magnetic field sensor comprising: at least one coil (108; 1302) responsive to an AC coil drive signal; at least one coil driver, connected to said coil (108; 1302) and configured to generate said AC coil drive signal; at least one magnetic field sensing element (104; 1308, 1310) responsive to a sensing element drive signal and configured to detect a directly coupled magnetic field generated by the at least one coil and to generate a magnetic field signal in response to the directly coupled magnetic field, wherein the at least one magnetic field sensing element comprises at least one first magnetic field sensing element having a first coupling factor with respect to the at least one coil and generating a first magnetic field signal and at least one second magnetic field sensing element having a second coupling factor with respect to the at least one coil and generating a second magnetic field signal, wherein the first coupling factor is different from the second coupling factor; a processor (112; 1332) responsive to the magnetic field signal to compute a sensitivity signal associated with detection of the directly coupled magnetic field and substantially independent of a reflected magnetic field reflected by a conductive target disposed proximate to the at least one magnetic field sensing element, wherein the processor is coupled to the first and second magnetic field sensing elements and the computed sensitivity signal comprises a difference between the first magnetic field signal and the second magnetic field signal; and said coil driver being configured to adjust said AC coil drive signal in response to said sensitivity signal; and an output signal generator configured to generate an output signal of the magnetic field sensor indicative of the reflected magnetic field. at least one coil (108; 1302) responsive to an AC coil drive signal; at least one coil driver, connected to said coil (108; 1302) and configured to generate said AC coil drive signal; at least one magnetic field sensing element (104; 1308, 1310) responsive to a sensing element drive signal and configured to detect a directly coupled magnetic field generated by the at least one coil and to generate a magnetic field signal in response to the directly coupled magnetic field, wherein the at least one magnetic field sensing element comprises at least one first magnetic field sensing element having a first coupling factor with respect to the at least one coil and generating a first magnetic field signal and at least one second magnetic field sensing element having a second coupling factor with respect to the at least one coil and generating a second magnetic field signal, wherein the first coupling factor is different from the second coupling factor; a processor (112; 1332) responsive to the magnetic field signal to compute a sensitivity signal associated with detection of the directly coupled magnetic field and substantially independent of a reflected magnetic field reflected by a conductive target disposed proximate to the at least one magnetic field sensing element, wherein the processor is coupled to the first and second magnetic field sensing elements and the computed sensitivity signal comprises a difference between the first magnetic field signal and the second magnetic field signal; and said coil driver being configured to adjust said AC coil drive signal in response to said sensitivity signal; and an output signal generator configured to generate an output signal of the magnetic field sensor indicative of the reflected magnetic field.