Harmonic suppression in unbalanced analogue MOSFET circuit topologies using body signals

Analytical and experimental results are presented which demonstrate that the nonlinearities of integrated MOS transistors operated in nonsaturation can be suppressed by driving the body terminals of these MOSFETs in an appropriate manner. In contrast with existing techniques, the proposed method does not require matched devices or balanced op-amps. It does require the correct choice of amplitude and phase of the body signal which is derived from the input signal. Experimental measurements show that individual even or odd harmonics can be reduced at least 90 dB below the fundamental in MOSFET-C filters/integrators, which compares favourably with results reported in the literature for balanced topology techniques.