High Efficiency Power Amplifiers for Modern Mobile Communications: The Load-Modulation Approach

Ramella, Chiara; Piacibello, Anna; Quaglia, Roberto; Camarchia, Vittorio; Pirola, Marco

doi:10.3390/electronics6040096

Cited by 35 publications

(26 citation statements)

References 123 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This feature article is focused on investigating the kinks in S 22 and h 21 for the gallium-nitride (GaN) high electron-mobility transistor (HEMT) technology, which is receiving increasing attention for high-temperature and high-power applications at high frequencies [22][23][24][25][26][27][28][29]. In particular, the kinks are studied at different ambient (i.e., case) temperatures (T a ) and bias voltages (V GS and V DS ).…”

Section: Introductionmentioning

confidence: 99%

A New Study on the Temperature and Bias Dependence of the Kink Effects in S22 and h21 for the GaN HEMT Technology

et al. 2018

View full text Add to dashboard Cite

The aim of this feature article is to provide a deep insight into the origin of the kink effects affecting the output reflection coefficient (S22) and the short-circuit current-gain (h21) of solid-state electronic devices. To gain a clear and comprehensive understanding of how these anomalous phenomena impact device performance, the kink effects in S22 and h21 are thoroughly analyzed over a broad range of bias and temperature conditions. The analysis is accomplished using high-frequency scattering (S-) parameters measured on a gallium-nitride (GaN) high electron-mobility transistor (HEMT). The experiments show that the kink effects might become more or less severe depending on the bias and temperature conditions. By using a GaN HEMT equivalent-circuit model, the experimental results are analyzed and interpreted in terms of the circuit elements to investigate the origin of the kink effects and their dependence on the operating condition. This empirical analysis provides valuable information, simply achievable by conventional instrumentation, that can be used not only by GaN foundries to optimize the technology processes and, as a consequence, device performance, but also by designers that need to face out with the pronounced kink effects of this amazing technology.

show abstract

Section: Introductionmentioning

confidence: 99%

A New Study on the Temperature and Bias Dependence of the Kink Effects in S22 and h21 for the GaN HEMT Technology

et al. 2018

View full text Add to dashboard Cite

show abstract

“…This network offers an approximated large-signal model for the Cree commercial GaN HEMT device CGH40010F (Cree Inc., Durham, NC, USA). For simplicity, it is feasible to use average drain voltage V ds to calculate C ds , and then S-parameters (S (P) ) of the embedding transfer network at different supply voltage can be computed conveniently utilizing the ABCD parameter matrix, as shown in Equation (2). Subsequently, the optimal impedances Z Igen at the current generation plane can transform to Z pkg at the package plane.…”

Section: Nonlinear Capacitance and Parasitic Modelmentioning

confidence: 99%

“…The dynamic wideband envelope and high peak-to-average power ratios (PAPRs) of 4G/5G waveforms challenge the RF power amplifier (PA) linearity-efficiency trade-off. Therefore, several architectures to improve the efficiency of RF PA have been investigated, e.g., Doherty, linear amplification with nonlinear components (LINC), envelope elimination and restoration (EER), and envelope tracking (ET) [1][2][3][4]. Unfortunately, architectures such as Doherty and LINC have bandwidth restrictions inherently.…”

Section: Introductionmentioning

confidence: 99%

Analytical Design Solution for Optimal Matching of Hybrid Continuous Mode Power Amplifiers Suitable for a High-Efficiency Envelope Tracking Operation

et al. 2019

View full text Add to dashboard Cite

An analytical method to design a power amplifier (PA) with an optimized power added efficiency (PAE) trajectory for envelope tracking (ET) architecture is proposed. To obtain feasible matching solutions for high-efficiency performance of the PA in the dynamic supply operation, hybrid continuous modes (HCM) architecture is introduced. The design space for load impedances of the HCM PAs with nonlinear capacitance is deduced mathematically using the device’s embedding transfer network, without the necessity of using load-pull. The proposed design strategy is verified with the implementation of a GaN PA operating over the frequency range of 1.9 GHz to 2.2 GHz with PAE between 67.8% and 72.4% in the 6.7 dB back-off power region of the ET mode. The ET experimental system was set up to evaluate the application of the PA circuit. Measurement results show that the ET PA at 2.1 GHz reaches the efficiency of 61%, 54%, 44% and an error vector magnitude (EVM) of 0.32%, 0.60%, 0.67% at an average output power of 34.4 dBm, 34.2 dBm, 34.1 dBm for 6.7 dB peak-to-average power ratios (PAPR) signals with 5 MHz, 10 MHz, and 20 MHz bandwidths, respectively. Additionally, tested by a 20 MHz bandwidth 16 quadrature amplitude modulation (QAM) signal, 41.8% to 49.2% efficiency of ET PA is achieved at an average output power of 33.5 dBm to 35.1 dBm from 1.9 GHz to 2.2 GHz.

show abstract

“…Power efficiency is a key feature for a PA conceived for space application, being solar-cells and batteries the only power supply available on board satellites, which still represents a great challenge at high frequency, often demanding for efficiency enhancement approaches [2]. Besides efficiency, high reliability and slow aging must be ensured in order to sustain long-term operation of the satellites (several years/decades of mission).…”

Section: Introductionmentioning

confidence: 99%

Thermal-aware GaN/Si MMIC design for space applications

Ramella

Pirola

Reale

et al. 2019

2019 IEEE International Conference on Microwaves, Antennas, Communications and Electronic Systems (COMCAS)

Self Cite

View full text Add to dashboard Cite

Thermal stress in microwave power devices is a major issue for space applications, with a detrimental impact on the operating lifetime of MMICs on board satellites. To limit this, derating rules are applied to the maximum operating junction temperature, which however limit the potential device performance when GaN/Si technology is employed. In this framework, classical power amplifier design paradigm must be reconsidered, moving to a thermal-aware design approach. To this aim, it is crucial to have access to highly reliable thermal models of the adopted devices. This work will show that, adopting a simplified but effective thermal model and proper design strategy, GaN/Si technology can be successfully adopted for space-compliant MMIC design up to Ka-band. In particular, the preliminary design of a 10 W MMIC working in Ka-band at 36 GHz will be presented based on the 100 nm gate-length GaN/Si HEMT process from OMMIC foundry.

show abstract

High Efficiency Power Amplifiers for Modern Mobile Communications: The Load-Modulation Approach

Cited by 35 publications

References 123 publications

A New Study on the Temperature and Bias Dependence of the Kink Effects in S22 and h21 for the GaN HEMT Technology

A New Study on the Temperature and Bias Dependence of the Kink Effects in S22 and h21 for the GaN HEMT Technology

Analytical Design Solution for Optimal Matching of Hybrid Continuous Mode Power Amplifiers Suitable for a High-Efficiency Envelope Tracking Operation

Thermal-aware GaN/Si MMIC design for space applications

Contact Info

Product

Resources

About