A Digital Polar Transmitter With DC–DC Converter Supporting 256-QAM WLAN and 40-MHz LTE-A Carrier Aggregation

This paper presents a power amplifier (PA) design, which consists of eight class-D PA units on a single 28-nm CMOS die and a coupled-line power combiner on printed circuit board (PCB). The PA utilizes tri-phasing modulation, which combines polar and outphasing components in a way that eliminates linearity-degrading effects of multilevel outphasing while maintaining the back-off efficiency. Each PA unit contains a cascoded output stage with a 3.6-V supply voltage, and multilevel operation is enabled by on/off logic circuitry. Our analysis shows that the choice of power-combiner type is vital for reducing PA supply and ground ripple and thus ensuring reliable operation. Accordingly, the power combiner is implemented with extended Marchand baluns, which consist of input transmission lines and coupled-line sections. Unlike the original Marchand balun, our new topology is feasible for implementation under the layout restrictions caused by the multiple-unit PA on a single die. Measurement results show the PA achieving a peak output power of 29.7 dBm with a 34.7% efficiency, and operation with aggregated LTE signals at 1.7-GHz carrier frequency is verified with bandwidths up to 100 MHz.

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“…In general, Y m1,c = Y 1m,c [21], and thus (34) and (35) show that the Y-parameter matrix is symmetric, i.e. Y mn,e = Y nm,e .…”

Section: A Analysis Of the Extended Marchand Balunmentioning

confidence: 99%

A Class-D Tri-Phasing CMOS Power Amplifier With an Extended Marchand-Balun Power Combiner

Martelius

Ryynänen

Stadius

et al. 2020

IEEE Trans. Microwave Theory Techn.

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“…The optimality equation in (8)  is the optimal solution of problem (7). Proof: The optimal equation 11is the subproblems for the entire optimization problem in (7).…”

Section: Properties Of the Optimal Policymentioning

confidence: 99%

“…Studies for LWA are illustrated in [7]- [11]. Zhu et al verifies the feasibility for carrier aggregation with 256-QAM WLAN and 40 MHz LTE in digital polar transmitter [7].…”

Section: Introductionmentioning

confidence: 96%

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Delay-Aware LTE WLAN Aggregation for 5G Unlicensed Spectrum Usage

Liu¹,

Zhu

2017

2017 IEEE 85th Vehicular Technology Conference (VTC Spring)

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In 5G heterogeneous evolution, the unlicensed band has captured much attention. Specified by 3GPP Release 13, LTE WLAN aggregation (LWA) is deemed as an effective approach for spectrum integration of 5G heterogeneous networks (HetNet). However, most of previous works about LWA lie in the architecture design, and rarely investigate LWA algorithm analytically. In this paper, we formulate the network access and aggregation problem for delay-tolerant application in multiple slots, and further develop a delay-aware LTE WLAN aggregation algorithm (DLWA) based on dynamic programming, which is aimed to minimize the user payment with QoS requirement. To reduce the complexity, we prove optimal decision policy and simplify the searching space of scheme sets. Simulation results show that, comparing with the current WLAN interworking solutions, the algorithm could lower the payment and achieve high completion probability under specified transmission deadline. The framework presented can support WLAN offloading scheme as well, which enables the best use of unlicensed resource.

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“…Among such transmitters, the optimal back-off power efficiency is typically achieved by architectures that utilize constant-envelope phase-modulated signals and a separate discrete-level amplitude signal. Specifically, this category includes polar [1]- [7] and multilevel outphasing transmitters [8]- [13].…”

Section: Introductionmentioning

confidence: 99%

Spectral Effects of Discrete-Time Amplitude Levels in Digital-Intensive Wideband Radio Transmitters

Martelius

Stadius

Lemberg

et al. 2018

2018 IEEE International Symposium on Circuits and Systems (ISCAS)

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This paper examines one source of spectral degradation in polar and multilevel outphasing transmitters. The degradation is caused by the amplitude signal appearing at the transmitter output as a baseband component, in addition to the desired RF signal. This baseband component contains sampling images and quantization noise across the spectrum. Thus, it adds noise at the signal band where it cannot be filtered and limits the achievable ACLR, particularly in wideband LTE and 5G systems. We analyze the origin of this phenomenon and related effects of system and signal parameters, and propose three design solutions for eliminating or alleviating the problem. Our analysis and simulations demonstrate that using a voltage-subtracting power combiner cancels the described degradation, potentially leading to significant improvement in spectral performance.

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A Digital Polar Transmitter With DC–DC Converter Supporting 256-QAM WLAN and 40-MHz LTE-A Carrier Aggregation

Cited by 18 publications

References 23 publications

A Class-D Tri-Phasing CMOS Power Amplifier With an Extended Marchand-Balun Power Combiner

A Class-D Tri-Phasing CMOS Power Amplifier With an Extended Marchand-Balun Power Combiner

Delay-Aware LTE WLAN Aggregation for 5G Unlicensed Spectrum Usage

Spectral Effects of Discrete-Time Amplitude Levels in Digital-Intensive Wideband Radio Transmitters

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