A Highly Efficient LTE Pulse-Modulated Polar Transmitter Using Wideband Power Recycling

作者：Yang Hao Shun^*; Chang Chun Wei; Chen Jau Horng

来源：IEEE Transactions on Microwave Theory and Techniques, 2015, 63(12): 4437-4443.

DOI：10.1109/TMTT.2015.2484349

• Long-term evolution (LTE)
• polar transmitters
• power amplifier linearization
• power amplifiers (PAs)
• rectifier

This paper presents a wideband power recycling technique for pulse-modulated polar transmitters (PMPTs). The technique allows unwanted out-of-band modulation spurs in PMPTs to be rectified and recovered back to the power supply for efficiency improvement. By configuring the power amplifiers as a balanced amplifier with dual-phase digital pulse-width modulation, the odd modulation spurs can be extracted directly from the isolation port of the output-combining quadrature coupler. Using the proposed architecture, the prototype transmitter achieved 59.1% drain efficiency at an output channel power of 26.2 dBm using a 10-MHz bandwidth long-term evolution 16-quadrature amplitude modulation test signal at 836.5 MHz. After output signal restoration by a surface-acoustic-wave filter, an output power level of 24.8 dBm and 42.8% drain efficiency were achieved while passing the spectral and receive-band-noise requirements without using any digital pre-distortion techniques.

• 出版日期2015-12