A.V. Shuvaev1, A.V. Bashkirov2
1,2 Voronezh State Technical University (Voronezh, Russia)
Formulation of the problem. Modern transmitters typically need to amplify and transmit complex signals with simultaneous frequency and phase modulation. Over the past ten years, there has been a very rapid development of wireless communication along with an increase in the number of frequency bands that must be supported in a wireless electronic device. The Class D high-frequency power amplifier has found a very wide application in modern communication systems, and it must support an increasing number of frequency ranges and operating modes. Modern designers usually solve this problem by simply increasing the number of power amplifiers, with each of them covering several adjacent frequency bands. This method works well for 2G-4G transmission systems, since the frequency range of these systems is <3 GHz, however, with the widespread adoption of 5G and the active development of 6G, not only will the number of frequency bands continue to increase, but the frequency range will expand to much higher ranges (~6 GHz, 30 GHz, 60 GHz, etc.). To solve this problem, there is a need to increase the critical characteristics of y, such as: efficiency, output power, linearity, throughput.
Purpose. Due to the fact that the critical characteristics of UHF are often mutually exclusive and an increase in some indicators leads to a decrease in other indicators, it is necessary to develop a methodology for assessing the importance of certain parameters. Results. As a result of the conducted research, it is concluded that one of the main characteristics of the power amplifier is linearity. The pursuit of high efficiency and high output power is possible only after the linearity requirement is met. The importance of linearity is due not only to the fact that it will distort baseband signals, but also to the radiation requirements of the International Communications Commissions. The paper shows that the linearity of the power amplifier can be improved by simply reducing the output power, but the drain efficiency will decrease. In the Class D power amplifier that is analyzed in this paper, the transistors are overloaded to hard saturation. The problem of non-linearity can be solved with the help of modern LINC technology (Linear Amplification using Nonlinear Components), which has become widespread in recent years.
Practical significance. The results obtained can be used in the design of modern high-frequency UHF class D with the achievement of high technical and operational characteristics.
Shuvaev A.V., Bashkirov A.V. Methods for improving the main characteristics of class d high-frequency amplifiers. Radiotekhnika. 2021. V. 85. № 6. P. 62−66. DOI: https://doi.org/10.18127/j00338486-202106-11 (In Russian)
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