CN-115913124-B - Power amplifier with fractional modulation

Abstract

The invention discloses a power amplifier with fractional modulation, and relates to the technical field of wireless communication. The power amplifier comprises a Doherty power amplifier for local modulation and a balance power amplifier for global modulation, wherein the Doherty power amplifier for local modulation comprises a first radio frequency signal input end, a power divider, a sub power amplifier D3, a sub power amplifier D4 and a load modulation network, the first radio frequency signal input end inputs a radio frequency signal to the sub power amplifier D3 and the sub power amplifier D4 through the power divider and is synthesized through the load modulation network after being amplified by the sub power amplifier, the balance power amplifier comprises a second radio frequency signal input end, an input coupler, the sub power amplifier D1, the sub power amplifier D2 and an output coupler, and the output of the Doherty power amplifier is connected to an isolation port of the balance power amplifier output coupler. The dynamic range is expanded, the main-path oversaturation phenomenon in the time sequence modulation power amplifier is solved, a system and complete technical foundation is established for the design of the broadband large-dynamic load modulation power amplifier, and the application scene of the wireless communication network is expanded.

Inventors

• SHI WEIMIN
• HU CHUNYU
• YANG RONGXING
• LI MINGYU
• PANG JINGZHOU
• DAI ZHIJIANG

Assignees

• 重庆大学

Dates

Publication Date

20260505

Application Date

20221121

Claims (5)

1. 1. A power amplifier with partial modulation is characterized by comprising a Doherty power amplifier for local modulation and a balanced power amplifier for global modulation; The locally modulated Doherty power amplifier comprises a radio frequency signal input end I, a power divider, a sub power amplifier D3, a sub power amplifier D4 and a load modulation network, wherein the radio frequency signal input end I inputs a radio frequency signal to the two sub power amplifiers D3 and D4 through the power divider, and the radio frequency signal is synthesized through the load modulation network after being amplified; the balanced power amplifier comprises a radio frequency signal input end II, an input coupler, a sub power amplifier D1, a sub power amplifier D2 and an output coupler; the output of the Doherty power amplifier is connected to an isolation port (port # 3) of the balanced power amplifier output coupler, and a phase compensation line is arranged before the locally modulated Doherty power amplifier or before the balanced power amplifier and used for adjusting the phase difference between the local Doherty power amplifier and the balanced power amplifier.
2. 2. The power amplifier with the sub-modulation of claim 1, wherein the sub-power amplifier D1, the sub-power amplifier D2, the sub-power amplifier D3 and the sub-power amplifier D4 are respectively provided with a broadband input matching network, an active transistor and a broadband output matching network which are sequentially connected in series, the active transistor is provided with a grid bias circuit and a drain bias circuit, the broadband input matching network matches the optimal source impedance of the active transistor to the system impedance, and the broadband output matching network matches the optimal load impedance of the active transistor to the system impedance.
3. 3. The sub-power amplifier of claim 2, wherein the broadband output matching networks of the two sub-power amplifiers D1 and D2 of the balanced power amplifier are respectively connected with the port #1 and the port #2 of the output coupler.
4. 4. The power amplifier with the sub-modulation of claim 2, wherein the two sub-power amplifiers D3 and D4 of the Doherty power amplifier are connected with the isolation port of the output coupler through the load modulation network, and the two sub-power amplifiers of the Doherty power amplifier are respectively a carrier power amplifier D3 and a peak power amplifier D4.
5. 5. The sub-modulated power amplifier of claim 2, wherein the gate bias circuit and the drain bias circuit are implemented with microstrip lines to provide a stable operating voltage for the active transistor by the DC power supply.

Description

Power amplifier with fractional modulation Technical Field The present invention relates to the field of wireless communication technology, and more particularly, to a power amplifier with fractional modulation. Background From simple voice communication to multimedia data transmission, from point-to-point communication to everything interconnection, contemporary wireless communication technology is deeply changing people's production and life style. As a core component in the radio frequency front end, the power consumption of the radio frequency power amplifier generally accounts for more than half of the total power consumption of the wireless communication transmitter. In addition, with the popularization of array technology, the power amplifier demand increases dramatically. Therefore, the development of the high-efficiency integrated power amplifier chip not only can effectively reduce the overall power consumption of the wireless base station, but also has extremely high academic value. Modern wireless communication systems, on the other hand, generally employ complex modulated signals and are increasingly bandwidth. This results in a constant rise in the signal peak-to-average ratio, which makes the average efficiency of the power amplifier more important than the peak efficiency. However, the conventional power amplifier has a fast drop in the back-off efficiency of the power, and the energy for processing the wideband modulation signal obviously cannot meet the system requirement. Furthermore, the number of 5G communication bands increases significantly and there is downward compatibility, meaning that broadband communication means are indispensable. For this reason, wideband Doherty power amplifier gradually takes the dominant position in the current base station market, and its bandwidth and dynamic expansion technology have been paid attention in recent years. Therefore, how to expand the dynamic range of the high-efficiency power amplifier while expanding the bandwidth is worth intensive research. In summary, the new-era communication is characterized by large quantity, large power consumption, wide bandwidth and high modulation in the field of radio frequency power amplification. Therefore, the high-efficiency broadband large-dynamic power amplifier becomes a focus of attention in the whole industry and is a research and development difficulty. Therefore, the research on the bandwidth and dynamic expansion technology of the high-efficiency power amplifier is significant, and the method has very broad market prospect in the 5G/6G and even future mobile communication fields. Disclosure of Invention The invention aims to provide a power amplifier with fractional modulation, which aims at overcoming the problems of the prior power amplifier in the aspects of dynamic range and working bandwidth and simultaneously provides a broadband design scheme of a balanced modulation type power amplifier. The power amplifier architecture with the broadband large dynamic load modulation characteristic solves the main-path oversaturation phenomenon in the time sequence load modulation balanced power amplifier through the proposed fractional modulation power amplification theory, and achieves the purpose of further expanding the high-efficiency power range on the premise of guaranteeing the broadband working state. The technical aim of the invention is realized by the following technical scheme that the power amplifier with partial modulation comprises a Doherty power amplifier for local modulation and a balance power amplifier for global modulation; The locally modulated Doherty power amplifier comprises a radio frequency signal input end I, a power divider, a sub power amplifier D3, a sub power amplifier D4 and a load modulation network, wherein the radio frequency signal input end I inputs a radio frequency signal to the two sub power amplifiers D3 and D4 through the power divider, and the radio frequency signal is synthesized through the load modulation network after being amplified; the balanced power amplifier comprises a radio frequency signal input end II, an input coupler, a sub power amplifier D1, a sub power amplifier D2 and an output coupler; the output of the Doherty power amplifier is connected to an isolation port (port # 3) of the balanced power amplifier output coupler, and a phase compensation line is arranged before the local Doherty power amplifier or before the balanced power amplifier and used for adjusting the phase difference between the local Doherty power amplifier and the balanced power amplifier. The power amplifier is further characterized in that the sub power amplifier D1, the sub power amplifier D2, the sub power amplifier D3 and the sub power amplifier D4 are respectively provided with a broadband input matching network, an active transistor and a broadband output matching network which are sequentially connected in series, the active transistor is connected with a grid bias circ