Complex Delta–Sigma-Based Transmitter With Enhanced Linearity Performance Using Pulsed Load Modulation Power Amplifier

Jouzdani, Maryam; Ebrahimi, Mohammad Mojtaba; Helaoui, Mohamed; Ghannouchi, Fadhel M.

doi:10.1109/tmtt.2017.2657499

Cited by 10 publications

(1 citation statement)

References 27 publications

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“…In this work, we used the CxDSM, as it presents a higher coding efficiency and reduces the power of the quantization noise [ 3 ]. The CxDSM in Figure 1 b was first presented in [ 8 , 9 ], and is based on simultaneous quantization of the in-phase component (I) and the quadrature-phase component (Q) of a complex signal. This technique exhibits more accurate quantization of the signal, resulting in higher coding efficiency and linearity than its Cartesian DSM (CDSM) counterpart [ 3 ].…”

Section: Complex Multi-bit Delta-sigma Modulatormentioning

confidence: 99%

Three-Level De-Multiplexed Dual-Branch Complex Delta-Sigma Transmitter

Arfi

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Aflaki

et al. 2018

Sensors

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In this paper, a dual-branch topology driven by a Delta-Sigma Modulator (DSM) with a complex quantizer, also known as the Complex Delta Sigma Modulator (CxDSM), with a 3-level quantized output signal is proposed. By de-multiplexing the 3-level Delta-Sigma-quantized signal into two bi-level streams, an efficiency enhancement over the operational frequency range is achieved. The de-multiplexed signals drive a dual-branch amplification block composed of two switch-mode back-to-back power amplifiers working at peak power. A signal processing technique known as quantization noise reduction with In-band Filtering (QNRIF) is applied to each of the de-multiplexed streams to boost the overall performances; particularly the Adjacent Channel Leakage Ratio (ACLR). After amplification, the two branches are combined using a non-isolated combiner, preserving the efficiency of the transmitter. A comprehensive study on the operation of this topology and signal characteristics used to drive the dual-branch Switch-Mode Power Amplifiers (SMPAs) was established. Moreover, this work proposes a highly efficient design of the amplification block based on a back-to-back power topology performing a dynamic load modulation exploiting the non-overlapping properties of the de-multiplexed Complex DSM signal. For experimental validation, the proposed de-multiplexed 3-level Delta-Sigma topology was implemented on the BEEcube™ platform followed by the back-to-back Class-E switch-mode power amplification block. The full transceiver is assessed using a 4th-Generation mobile communications standard LTE (Long Term Evolution) standard 1.4 MHz signal with a peak to average power ratio (PAPR) of 8 dB. The dual-branch topology exhibited a good linearity and a coding efficiency of the transmitter chain higher than 72% across the band of frequency from 1.8 GHz to 2.7 GHz.

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Section: Complex Multi-bit Delta-sigma Modulatormentioning

confidence: 99%