An Efficient Linearization Scheme for a Digital Polar EDGE Transmitter

Mehta, Jaimin; Zoicas, Vasile; Eliezer, Oren; Staszewski, Robert Bogdan; Rezeq, S.; Entezari, M.; Balsara, Poras T.

doi:10.1109/tcsii.2010.2041811

Cited by 27 publications

(16 citation statements)

References 13 publications

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“…The measured spectral performance at 400 kHz offset and the ACLR at 5 MHz is comparable to state-of-the-art EDGE [2] and WCDMA [16] transmitters.…”

Section: B Measured Performance Of Modulated Signalsmentioning

confidence: 66%

“…To benefit from the CMOS scaling in terms of power consumption and silicon area, a highly "digital" transmitter is desirable in the development of mobile multistandard RF transceivers [1]. Potential solutions are the polar transmitter, shown for EDGE [2], and the outphasing transmitter [3].…”

Section: Introductionmentioning

confidence: 99%

“…In practice the two amplifier stages and signals will experience gain and phase imbalances, creating nonlinearities and spectral distortion [4]. Previous predistortion methods of RF power amplifiers (PA) include model- based predistorters using model structures such as Volterra series [5], parallel Hammerstein structures [6], or look-up tables [2], which also can be made adaptive [7].…”

Section: Introductionmentioning

confidence: 99%

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Phase Predistortion of a Class-D Outphasing RF Amplifier in 90 nm CMOS

Fritzin

Jung

Landin

et al. 2011

IEEE Trans. Circuits Syst. II

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Abstract-This paper presents a behavioral model structure and a model-based phase-only predistortion method suitable for outphasing RF amplifiers. The predistortion method is based on a model of the amplifier with a constant gain factor and phase rotation for each outphasing signal, and a predistorter with phase rotation only. The method has been used for EDGE and WCDMA signals applied to a Class-D outphasing RF amplifier with an on-chip transformer used for power combining in 90nm CMOS. The measured peak power at 2 GHz was +10.3 dBm with a drain efficiency and power-added efficiency of 39 % and 33 %, respectively. For an EDGE 8-PSK signal with a phase error of 3• between the two input outphasing signals, the measured power at 400 kHz offset was -65.9 dB with predistortion, compared to -53.5 dB without predistortion. For a WCDMA signal with the same phase error between the input signals, the measured ACLR at 5 MHz offset was -50.2 dBc with predistortion, compared to -38.0 dBc without predistortion.

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“…The measured spectral performance at 400 kHz offset and the ACLR at 5 MHz is comparable to state-of-the-art EDGE [2] and WCDMA [16] transmitters.…”

Section: B Measured Performance Of Modulated Signalsmentioning

confidence: 66%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Phase Predistortion of a Class-D Outphasing RF Amplifier in 90 nm CMOS

Fritzin

Jung

Landin

et al. 2011

IEEE Trans. Circuits Syst. II

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“…A constant-envelope phaseonly signal going through a phase-modulation path is multiplied with the signal envelope going through an envelope-modulation path in a switched-mode power amplifier (PA) to reconstruct the original baseband complex signal (I + jQ). The high power efficiency is achieved by using a nonlinear switched-mode PA to handle the constant-envelope phase-modulated RF signal, and the good linear transmission is accomplished by modulating the signal envelope through the supply voltage of the switched-mode PA [2]. Fig.…”

Section: Introductionmentioning

confidence: 99%

Polar Transmitter with Differential DSM Phase and Digital PWM Envelope

Zhou

Liu²

2014

JSTS:Journal of Semiconductor Technology and Science

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Abstract-A low-power low-cost polar transmitter for EDGE is designed in 0.18µm CMOS. A differential delta-sigma modulator (DSM) tunes a three-terminal voltage-controlled oscillator (VCO) to perform RF phase modulation, where the VCO tuning curve is digitally pre-compensated for high linearity and the carrier frequency is calibrated by a dual-mode lowpower frequency-locked loop (FLL). A digital intermediate-frequency (IF) pulse-width modulator (PWM) drives a complementary power-switch followed by an LC filter to achieve envelope modulation with high efficiency. The proposed transmitter with 9mW power dissipation relaxes the time alignment between the phase and envelope modulations, and achieves an error vector magnitude (EVM) of 4% and phase noise of −123dBc/Hz at 400kHz offset frequency.

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“…Earlier predistortion methods of RF PAs include modelbased predistorters using model structures such as Volterra series [23]- [25], parallel Hammerstein structures [26], or lookup tables (LUT) [27], which also can be made adaptive [28], [29]. Compared to conventional linear PAs, the outphasing PA takes two constant envelope signals to create an amplitude and phase modulated output signal.…”

mentioning

confidence: 99%

Least-Squares Phase Predistortion of a +30 dBm Class-D Outphasing RF PA in 65 nm CMOS

Jung

Fritzin

Enqvist

et al. 2013

IEEE Trans. Circuits Syst. I

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Abstract-This paper presents a model-based phase-only predistortion method suitable for outphasing radio frequency (RF) power amplifiers (PA). The predistortion method is based on a model of the amplifier with a constant gain factor and phase rotation for each outphasing signal, and a predistorter with phase rotation only. Exploring the structure of the outphasing PA, the model estimation problem can be reformulated from a nonconvex problem into a convex least-squares problem, and the predistorter can be calculated analytically. The method has been evaluated for 5 MHz Wideband Code-Division Multiple Access (WCDMA) and Long Term Evolution (LTE) uplink signals with Peak-to-Average Power Ratio (PAPR) of 3.5 dB and 6.2 dB, respectively, applied to one of the first fully integrated +30 dBm Class-D outphasing RF PA in 65nm CMOS. At 1.95 GHz for a 5.5 V (6.0 V) supply voltage, the measured output power of the PA was +29.7 dBm (+30.5 dBm) with a power-added efficiency (PAE) of 27 %. For the WCDMA signal with +26.0 dBm of channel power, the measured Adjacent Channel Leakage Ratio (ACLR) at 5 MHz and 10 MHz offsets were -46.3 dBc and -55.6 dBc with predistortion, compared to -35.5 dBc and -48.1 dBc without predistortion. For the LTE signal with +23.3 dBm of channel power, the measured ACLR at 5 MHz offset was -43.5 dBc with predistortion, compared to -34.1 dBc without predistortion.

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An Efficient Linearization Scheme for a Digital Polar EDGE Transmitter

Cited by 27 publications

References 13 publications

Phase Predistortion of a Class-D Outphasing RF Amplifier in 90 nm CMOS

Phase Predistortion of a Class-D Outphasing RF Amplifier in 90 nm CMOS

Polar Transmitter with Differential DSM Phase and Digital PWM Envelope

Least-Squares Phase Predistortion of a +30 dBm Class-D Outphasing RF PA in 65 nm CMOS

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