scholarly journals Doherty Power Amplifier for LTE-Advanced Systems

Technologies ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 60 ◽  
Author(s):  
Abdulkhaleq ◽  
Yahya ◽  
Al-Yasir ◽  
Parchin ◽  
McEwan ◽  
...  

The design and implementation of an asymmetrical Doherty power amplifier are discussed, where two Cree GaN High Electron Mobility Transistors (HEMTs) devices are used for designing an asymmetrical Doherty power amplifier to achieve saturated power of 48 dBm and optimal back-off efficiency of 8 dB in the frequency band of 3.3–3.5 GHz. Rogers RO4350B material is used as a substrate material, a back-off of 8 dB was achieved with an average gain of 10 dB. Load-pull data are an important tool for determining the optimum load impedance that the transistor needs to see. Additionally, the measured efficiency was 50% when the designed amplifier was tested by a modulated signal of 8 dB peak-to-average-power ratio when the average output power was 40 dBm. At the same time, the linearity of the designed amplifier was measured and found 31.8 dB which can be improved using a digital pre-distorter. The gain phase measurement can be used as an indicator for compensating the phase difference between the two cells.

Author(s):  
Ildu Kim ◽  
Junghwan Moon ◽  
Jungjoon Kim ◽  
Seunghoon Jee ◽  
Junghwan Son ◽  
...  

This paper demonstrates a highly efficient 3-stage Doherty power amplifier (PA) employing an envelope tracking (ET) technique. The ‘3-stage’ Doherty PA is the most efficient architecture for a high peak-to-average power ratio (PAPR) signal among the various Doherty PAs. However, because of the lower peaking biases than those of the ‘N-way’ Doherty PA, the proper load modulation is hard to be achieved. To get proper modulation, the peaking PAs' gate biases have been adaptively controlled using the ET technique, and the peak power and maximum efficiency characteristic along the backed-off output power region is successfully achieved. By ADS and Matlab simulations, the overall behavior of the 3-stage Doherty PA employing the ET technique has been fully analyzed. To maximize the overall efficiency of the proposed 3-stage Doherty PA, the unit PA has been designed using class F−1 PA. For verification, the amplifier is implemented using 5 W and 10 W PEP LDMOSFETs for the 802.16e mobile world interoperability for microwave access (WiMAX) at 1 GHz with a 8.5 dB PAPR. The measured drain efficiency of the proposed 3-stage Doherty PA is 55.5% at an average output power of 37 dBm, which is a 7.54 dB backed-off output power. The digital feedback predistortion (DFBPD) algorithm has been used to linearize the proposed PA considering the ET technique. After linearization, the −33.15 dB of relative constellation error (RCE) performance is achieved, satisfying the system specification. These results show that the 3-stage Doherty employing the ET technique and saturated PA is the most suitable PA for the highly efficient and linear transmitter.


Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2327
Author(s):  
Fei Yang ◽  
Jun Li ◽  
Hongxi Yu ◽  
Sen Yan ◽  
Anxue Zhang ◽  
...  

In this paper, the design and implementation of a Doherty power amplifier (DPA) are proposed using gallium nitride high electron mobility transistors (GaN HEMTs). Class-F and Class-C modes are combined to obtain an asymmetric DPA. The precise active load-pull controlling of fundamental and harmonic terminations of the DPA is simulated and analyzed, including the parasitics of the transistors. The measurements of the DPA with the phase difference, input power ratio adjustment, and envelope tracking of the auxiliary PA are discussed in detail in order to achieve a competitive performance. A greater than 63% drain efficiency is obtained within the 10-dB input power dynamic range at 2.1 GHz. The peak of the drain efficiency reaches 73%, with a corresponding output power of 46 dBm.


2021 ◽  
Author(s):  
Pouya Jahanian ◽  
Azadeh Norouzi Kangarshahi

Abstract In this paper, an attempt has been made to design a Doherty power amplifier (DPA) with high-gain and wide-band. For this purpose, two peak amplifiers are used to improve the performance of the main amplifier. Main and auxiliary amplifiers with the same structure to the class-AB type and by using micro-strip lines in place of input/output and load matching networks, transmission lines and inductors of drain and gate, that minimize the losses in the DPA. The current DPA is implemented with GaN_HEMT_CLF1G0530_100v transistor and Rogers4003 substrate, which for 1GHz frequency in 0.5-1.5GHz bandwidth will be able to be at P-1dB point (this point, input power as 30dBm and output power as 47.98dBm) increase Drain efficiency and Power added efficiency (PAE) to 81.95% and 80.73%, respectively. The DPA helps to expand the back-off region and extend the linearity region, so the Peak to average power ratio (PAPR) will be 5.21dB and the Adjacent channel power ratio (ACPR) as 58.7dBc. A gain of 17.06-17.92dB was also obtained, which is significant compared to the results of similar samples.


2013 ◽  
Vol 760-762 ◽  
pp. 546-550 ◽  
Author(s):  
Wen Sheng Pan ◽  
Chuan Hui Ma ◽  
Shi Hai Shao ◽  
You Xi Tang

An unsymmetrical GaN based Doherty power amplifier (DPA) operating from 2.5GHz to 2.7GHz is presented in this paper. To achieve a good tradeoff among the output power, efficiency and bandwidth, the ladder-type multisection output matching networks are optimized for the carrier amplifier and the peaking amplifier, respectively. Measured with continuous wave (CW) signal, the broadband DPA provides more than 49dBm saturation power in the operating band. The drain efficiency is greater than 44% over 7dB back-off power. For a LTE-Advanced signal with 100MHz bandwidth, the drain efficiency is higher than 42% at an average output power of 41dBm, along with an adjacent channel leakage ratio (ACLR) of better than-49.9dBc after digital predistortion (DPD).


2013 ◽  
Vol 61 (12) ◽  
pp. 4179-4187 ◽  
Author(s):  
Ahmed Mohamed Mahmoud Mohamed ◽  
Slim Boumaiza ◽  
Raafat R. Mansour

2013 ◽  
Vol 347-350 ◽  
pp. 1768-1772
Author(s):  
Chuan Hui Ma ◽  
Wen Sheng Pan ◽  
You Xi Tang ◽  
Chao Jin Qing

An unsymmetrical Doherty power amplifier (DPA) at 460MHz is presented in this paper. The carrier and peaking amplifier of the DPA, which base on two equal-sized devices, are matched with different networks to mitigate the performance degradation caused by the limited load modulation. Measured with continuous wave (CW), the unsymmetrical DPA saturates at an output power of 49.2dBm and achieves a drain efficiency of 51% at 6dB back-off. Using a one-carrier long term evolution advanced (LTE-Advanced) signal with 20MHz bandwidth, the unsymmetrical DPA exhibits a drain efficiency of 48.7% at an average output power of 42.1dBm, along with adjacent channel leakage ratio (ACLR) of-34.1dBc and-53.3dBc before and after digital pre-distortion (DPD), respectively.


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