TR2015-006

Outphasing Multi-Level RF PWM for Inter-Band Carrier Aggregation in Digital Transmitters


    •  Chung, S.; Ma, R.; Teo, K.H.; Parsons, K., "Outphasing Multi-Level RF PWM for Inter-Band Carrier Aggregation in Digital Transmitters", IEEE Radio Wireless Week (RWW), January 2015.
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      • @inproceedings{Chung2015jan,
      • author = {Chung, S. and Ma, R. and Teo, K.H. and Parsons, K.},
      • title = {Outphasing Multi-Level RF PWM for Inter-Band Carrier Aggregation in Digital Transmitters},
      • booktitle = {IEEE Radio Wireless Week (RWW)},
      • year = 2015,
      • month = jan,
      • url = {http://www.merl.com/publications/TR2015-006}
      • }
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  • Research Areas:

    Electronics & Communications, Wireless Communications


A novel non-contiguous concurrent multiband digital-RF transmitter architecture is presented, which is based on outphasing the multi-level RF pulse-width modulated signals (MLRF-PWM) for digital Class-S power amplifiers. In order to improve the transmitter power efficiency, the outphasing modulation in the proposed architecture effectively increases the number of MLRFPWM signal output levels. In addition, a multi-band multibit band-pass delta-sigma modulator (BPDSM) with a hard clipping technique is introduced, which further improves power coding efficiency by trading off distortion performance with coding efficiency. Experimental results with a dual-channel 25-GSPS arbitrary waveform generator (AWG) demonstrate non-contiguous carrier aggregation for 3-level Class-S PAs with inter-band LTE signals at 874 MHz and 1501 MHz for the channel bandwidth of 10-MHz and 20-MHz, respectively. The proposed outphasing MLRF-PWM technique achieves 59.5% power coding efficiency, which is significant improvement from the 8.6% coding efficiency of conventional 3-level BPDSM with the experimental dualband LTE signal transmission.