TR2017-144

A Concurrent Triple-Band Digital Transmitter Using Feedforward Noise Cancellation for Delta-Sigma Modulation


    •  Chung, S., Ma, R., Teo, K.H., "A Concurrent Triple-Band Digital Transmitter Using Feedforward Noise Cancellation for Delta-Sigma Modulation", European Microwave Conference, DOI: 10.23919/​EuMC.2017.8231049, October 2017.
      BibTeX TR2017-144 PDF
      • @inproceedings{Chung2017oct,
      • author = {Chung, SungWon and Ma, Rui and Teo, Koon Hoo},
      • title = {A Concurrent Triple-Band Digital Transmitter Using Feedforward Noise Cancellation for Delta-Sigma Modulation},
      • booktitle = {European Microwave Conference},
      • year = 2017,
      • month = oct,
      • doi = {10.23919/EuMC.2017.8231049},
      • url = {https://www.merl.com/publications/TR2017-144}
      • }
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  • Research Area:

    Electric Systems

Abstract:

A concurrent triple-band digital transmitter architecture with relaxed RF output filter requirement is presented in this paper. With non-contiguous inter-band carrier aggregation, all digital transmitters based on delta-sigma modulation and pulse-width modulation have suffered from out-of-band noise and spurious tones, requiring extremely demanding RF output filter design. We demonstrate a feedforward noise cancellation technique in order to suppress the out-of-band quantization noise of concurrent triple-band delta-sigma modulation for the first time. An experimental prototype based on an asymmetric RF power combiner and a 5-bit 7-GS/s DAC for noise cancellation realizes concurrent triple-band transmission of LTE Advanced signals, which consist of 710 MHz, 1750 MHz, and 2510 MHz bands with 30-MHz aggregated total bandwidth. The prototype achieves better than 42-dB spurious-free dynamic range (SFDR) and -47-dBc adjacent channel power ratio (ACPR), enabled by up to 12-dB out-of-band noise suppression.

 

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