Performance analysis and comparison of multi-level hard limiters

A general formula, using a Fourier sine-series representation, is derived for the input-output characteristic of multilevel hard limiters (MHLs) with unequal output jumps occurring at unequally spaced inputs. Using this formula, closed-form expressions involving ordinary Bessel functions are obtained for the harmonic and intermodulation performance of MHLs excited by multisinusoidal inputs with arbitrary amplitudes. The results show that, compared to the ideal hard limiter, MHLs can result in a reduction in the relative third harmonic distortion of about 40dB, and a reduction in relative third-order intermodulation distortion of about 19dB depending on the amplitude of the input sinusoids and the shape of the MHL characteristic. Using the proposed model it is possible to generate a database for the harmonic and intermodulation performance of any MHL with arbitrary values of jumps and their locations. Simulation results obtained using the harmonic balance simulator controller in the advanced design system design automation software confirm the accuracy of the proposed technique.