A Technique for Implementing Wide Dynamic-Range Polar Transmitters

This paper presents a technique for implementing wide dynamic-range polar transmitters based on the envelope elimination and restoration technique. The fast-varying instantaneous output power level is controlled by a switch that modulates the input signal of the power amplifier (PA), whereas the slow-varying average power level is controlled by changing the dc voltage of the drain of the PA. A cellular band prototype transmitter system is constructed using commercially available components. Using a CDMA2000 1× signal with 4.5-dB peak-to-average power ratio at 836.5 MHz, the prototype transmitter achieved a dynamic range of over 80 dB while passing the adjacent and alternate channel power ratios for the CDMA2000 standard without the use of digital pre-distortion or calibration.