Methods for Increasing the Efficiency of Amplitude-Phase Modulated Signals Power Amplifiers

Despite the widespread development of satellite mobile communications, radio communications in the high frequency range (3 - 30 MHz) retains its position when it is necessary to ensure over-the-horizon data transmission with low delays. The transmission speed of samples from the world's leading manufacturers reaches 120 kbit/s with a used radio channel width of 24 kHz. Manpack radios place high demands on weight and size characteristics, which are largely determined by the efficiency of the most energy-intensive unit - the power amplifier (PA). The article analyzes ways to increase the PA efficiency taking into account the features of modern telecommunication signals that use amplitude-phase modulation and have a large crest factor. Based on a preliminary analysis of a wide range of directions for increasing the radio frequency amplifiers efficiency, the most promising options for the problem under consideration are selected: a power amplifier with envelope elimination and restoration (EER) and an amplifier using the outphasing method. To date, the theoretical issues of constructing the EER PA and the prospects for its practical implementation have been better developed. At the same time, the potential capabilities of a transmitter built using the outphasing method are higher than those of the EER PA, since it does not have an inertial low-frequency envelope path, which reduces both energy performance and limits the possibility of improving quality characteristics. A conclusion is made about the advisability of further research, modeling, prototyping and testing of the transmitter using the outphasing method.