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

Abstract

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.

Broadband and Efficient Envelope Amplifier for Envelope Elimination and Restoration/Envelope Tracking Higher-Efficiency Power Amplifiers

“…When the channels are connected in parallel, the main energy from the power source enters the load through the amplifier switching channel, and only a small part of it (to correct errors of the switching channel regulation) through the linear channel. This is the most common solution [ 12 , 13 , 14 ]. With this design of the amplifier, the overall efficiency is fundamentally higher than when the channels are connected in series; however, the level of distortion (with similar low-pass filter parameters) is higher.…”

A Cross-Mode Universal Digital Pre-Distortion Technology for Low-Sidelobe Active Antenna Arrays in 5G and Satellite Communications

“…Active antenna arrays are the most critical enablers in the development of highperformance 5G and satellite communication systems owing to their beam-steering capability of confining power emissions produced by radio-frequency (RF) power amplifiers (PAs) [1][2][3]. In order to improve the efficiency of PAs, the PAs are commonly driven to their saturation modes, which features high nonlinearities and may lead to severe distortion of the signals.…”

“…Moreover, to meet the need to increase spectrum capacity and multiplexing, advanced modulation schemes, such as orthogonal frequency division multiplexing (OFDM) and similar derivatives, are being used for next-generation high throughput satellite communication systems [4]. These signals usually feature a high peak-to-average power ratio (PAPR) and are sensitive to the inherent nonlinearity distortions caused by RF PAs [1].…”