Linear and efficient three-level polar delta-sigma modulator based transmitter

This paper presents a linear high efficiency three-level polar DSM based transmitter that is adequate for wireless RF applications. The polar DSM runs at low sampling frequency that is related to the used oversampling ratio and the bandwidth of the signal standard. Through simulation, a high coding efficiency and high linearity can be achieved concurrently by adjusting the power level of the input signal. A three-level polar DSM was used to drive a switched mode power amplifier to propose a linear high efficiency transmitter that does not need a high sampling frequency. Two quantizers are used in order to preserve the linearity of the transmitter. A sampling frequency of 160 MHz was used for a Worldwide Interoperability for Microwave Access signal has a bandwidth of 1.25 MHz and oversampling ratio of 128. The transmitter has an overall efficiency equal 42% and linearity of 46 dB is achievable with sacrificing a bit of the efficiency.