Taking the same mathematical approach to look at the differential approach there can be seen an inherent cancellation of even-order harmonics, a benefit similar to the previously discussed common mode interference immunity. Again, a non-linear device, in this case a differential amplifier block, is described by a power-series expansion transfer function and is supplied with a pair of sinusoids of opposite polarities – these represent a differential signal at the device’s inputs. Through expansion, the cancellation effect of the differential block is shown.