Innovative Power Amplifier Circuits for Sub-6GHz, 5G Cellular Radio.

Project: Research

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The efficiency and linearity of radio frequency power amplifiers has been one of the limiting factors in the use of modulating schemes used in wireless communication systems. In first generation cellular radio, FM was used because of the need to use high efficiency amplifiers operating in class C. This has undergone numerous transformations and has now been made more challenging with the advent of 5G cellular radio. 5G usage scenarios can be divided into three spectrums, below 2GHz, 2-6GHz and above 6GHz. Each spectrum have their own usage scenarios and this proposal intends to address the sub-6GHz band. The base station power amplifier (PA) is the main consumer of electrical power which becomes even more of a problem as they will proliferate even more in 5G cellular radio. They are also the main contributor of distortion and interference within wireless communication systems. RF power amplifiers used in 5G, will be required to operate at the output back-off region, because of the use of the more spectrally efficient modulated signal. These more efficient modulated signals have a high peak to average power ratio (PAPR) which require operation at back-off in order to mitigate adjacent channel interference problems. Carrier aggregation techniques are also used for high data speed but requires each component within the wireless system to operate over a broad bandwidth. The Doherty power amplifier (Doherty PA) has become the amplifier of choice in base station PA design in past decades due to its additional efficiency peak at back-off. This allows higher efficiency operation at lower power levels. However, most existing Doherty PA works cannot satisfy the strict requirements of 5G wireless systems, without a dramatic increase in costs due to the need to combine numerous amplifiers at a high loss in power. In this proposal, the design of power amplifiers for use in 5G base stations based on innovative circuit techniques are investigated for the sub-6 GHz. The main challenge in designing power amplifiers, will be to achieve high performances (including efficiency, linearity and ultra-wide bandwidth) using innovative circuit techniques. The works proposed in this project will include a number of solutions for different application scenarios in 5G wireless communication systems.  


Project number9042969
Grant typeGRF
Effective start/end date1/09/20 → …