TR2015-004

Concurrent Multiband Digital Outphasing Transmitter Architecture Using Multidimensional Power Coding


    •  Chung, S.; Ma, R.; Shinjo, S.; Nakamizo, H.; Parsons, K.; Teo, K.H., "Concurrent Multiband Digital Outphasing Transmitter Architecture Using Multidimensional Power Coding", IEEE Transactions on Microwave Theory and Techniques, DOI: 10.1109/TMTT.2014.2387845, ISSN: 0018-9480, Vol. 63, No. 2, pp. 598-613, February 2015.
      BibTeX Download PDF
      • @article{Chung2015feb,
      • author = {Chung, S. and Ma, R. and Shinjo, S. and Nakamizo, H. and Parsons, K. and Teo, K.H.},
      • title = {Concurrent Multiband Digital Outphasing Transmitter Architecture Using Multidimensional Power Coding},
      • journal = {IEEE Transactions on Microwave Theory and Techniques},
      • year = 2015,
      • volume = 63,
      • number = 2,
      • pages = {598--613},
      • month = feb,
      • doi = {10.1109/TMTT.2014.2387845},
      • issn = {0018-9480},
      • url = {http://www.merl.com/publications/TR2015-004}
      • }
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    Electronics & Communications


All-digital outphasing transmitter architecture using
multidimensional power coding (MDPC) is proposed for
non-contiguous concurrent multiband transmission with a high
power efficiency. MDPC transforms multiband digital baseband
signals into multi-bit low-resolution digital signals that drive
switching-mode PAs. A prototype digital outphasing transmitter
consists of two 1-GHz bandwidth GaN Class-D PAs and a Chireix
power combiner. The two GaN PAs are driven by bipolar RF
PWM signals, which are transformed from a concurrent
dual-band LTE signal by MDPC. The dual-band LTE signal with
15-MHz aggregate channel bandwidth at 240 MHz and 500 MHz
frequency band is transmitted with -30 dBc and -37 dBc
out-of-band emissions, respectively. Digital outphasing achieves
more than two times higher coding efficiency than conventional
concurrent dual-band digital transmitters with the same PAs in
Class-S operation. Measured power coding efficiencies of 35.4%
and 47.1% are observed with outphasing bipolar and 3-level RF
PWM signals respectively, which are encoded from the dual-band
LTE signal.