A tri-band SAW-less WCDMA/HSPA RF CMOS transceiver with on-chip DC-DC converter connectable to battery

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%

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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“…Thus, the predistortion method improves the measured ACLR to have at least 12.6 dB of margin to the requirements [51], [52]. The measured ACLR at 5 MHz is comparable to state-of-the-art WCDMA [53], [54] transceivers.…”

Section: B Measured Performance Of Modulated Signalsmentioning

confidence: 94%

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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“…Comparing the histograms, the turned-on loop results in a distribution peak around -100 dBV p while the turned-off loop results in more evenly distributed values with a large number of iterations close to the specification limit. The in-band IIP 3 for interferers close to f LO with the mixer switching was simulated with a SpectreRF QPSS plus qpac analysis. The QPSS large frequency was equal to f LO while the first interferer was the QPSS moderate signal.…”

Section: Specifications and Calculationsmentioning

confidence: 99%

“…Conventional WCDMA LNA and mixer architectures are differential and an external SAW filter is required between the LNA and mixer [1][2][3] if the receiver linearity is too low. The purpose of the SAW filter is to attenuate the TX-signal that leaks into the LNA through the finite isolation of the duplexer.…”

Section: Introductionmentioning

confidence: 99%

A BiCMOS single ended multiband RF-amplifier and mixer with DC-offset and second order distortion suppression

Tired

2011

Analog Integr Circ Sig Process

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Direct conversion receivers are widely used for full duplex mobile radio communication systems. This paper describes a novel SAW-less single-ended RF amplifier connected to a single-ended mixer with a feedback loop that suppresses the second-order distortion from TX cross modulation of the LO-leakage as well as DCoffset at the mixer output. In Monte Carlo simulations the design achieves ?47 dBm minimum IIP 2 with 32 dB conversion voltage gain. The advantage with the proposed architecture is that it is fully single-ended. Especially in multiband integrated radios this is highly desirable since the pin-count for the LNAs is reduced by half. The PCB routing of the RF input signal is simplified. The design requires two off-chip filter capacitors of non critical value intended to be placed on the laminate inside the package.

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A tri-band SAW-less WCDMA/HSPA RF CMOS transceiver with on-chip DC-DC converter connectable to battery

Cited by 23 publications

References 5 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

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

A BiCMOS single ended multiband RF-amplifier and mixer with DC-offset and second order distortion suppression

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