Limit-cycle based, self-oscillating amplifiers are promising candidates for linear amplification of complex signals with high peak-to-average ratio, while maintaining high power efficiency. Limit-cycle transmitters employ switch class-D power amplifiers in order to achieve high Efficiency. In this work, accurate expressions have been derived to evaluate powerefficiency of a class-D amplifier in a limit-cycle loop considering the special conditions that apply in this configuration. A general statistical random signal is considered as the input signal and its multisine representation has been employed to facilitate the calculations. A novel approach has been used to determine accurate expressions for the output power and power efficiency of the circuit. Results are in good agreement with circuit simulations (Spectre) of a CMOS 60nm class-D power amplifier. Index Terms — Limit cycle amplifier, efficiency, linearity, RF power amplifier, power amplifiers.
|Title of host publication||Proceeding of ProRISC 2009, 26-26 november 2009, Veldhoven, The Netherlands|
|Publication status||Published - 2009|