Abstract: A modulator and a method are disclosed. The modulator is for generating a band pass signal and comprises: sigma delta modulation logic operable to receive an input signal and to perform at least a 3-level quantisation of the input signal to generate an at least 3-level quantised signal; and requantisation logic operable to requantise the at least 3-level quantised signal to a 2-level quantised signal to be provided as the band pass signal. This approach improves the coding efficiency achieved compared to that possible using a 2-level sigma delta modulator, whilst also providing improved noise performance due to the inherent linearity of the 2-level quantised signal which is provided to drive the switch mode power amplifier. Accordingly, the performance of the modulator is improved by increasing its coding efficiency whilst maintaining its linearity which improves the noise performance in adjacent channels.

Abstract: A modulator and a method are disclosed. The modulator is for generating a band pass signal and comprises: sigma delta modulation logic operable to receive an input signal and to perform at least a 3-level quantisation of the input signal to generate an at least 3-level quantised signal; and requantisation logic operable to requantise the at least 3-level quantised signal to a 2-level quantised signal to be provided as the band pass signal. This approach improves the coding efficiency achieved compared to that m possible using a 2-level sigma delta modulator, whilst also providing improved noise performance due to the inherent linearity of the 2-level quantised signal which is provided to drive the switch mode power amplifier. Accordingly, the performance of the modulator is improved by increasing its coding efficiency whilst maintaining its linearity which improves the noise performance in adjacent channels.