Active load modulation transmitter based on space coupling

Abstract

The invention discloses an active load modulation transmitter based on space coupling and belongs to the field of radio frequency transmitters of the wireless communication technology. The transmitter is of a transmitter structure for completing the active load modulation function through coupling between antenna units of the transmitter and is respectively connected with a main path power amplifier, an auxiliary path power amplifier and corresponding transmitting antennae in the position of a power splitter, and thus two unit radiating antenna arrays are formed. To achieve the active load modulation characteristic, the main path power amplifier is set in the AB-class state in a biasing mode, the auxiliary path power amplifier is set in the C-class state in a biasing mode, and a phase shifter is connected between the power splitter and the auxiliary path power amplifier. The two unit radiating antennae are close to each other, and thus sufficient electromagnetic coupling between the radiating antenna units is achieved, and the load modulation purpose is achieved. Meanwhile, a quarter-wave impedance conversion element in a traditional Doherty power amplifier structure is omitted, the structure of the transmitter is simplified, and the efficiency and the bandwidth of the system are promoted.

Description

technical field [0001] The invention belongs to the field of radio frequency transmitters of wireless communication technology. In particular, it relates to an active load modulation transmitter based on space coupling, in particular, the efficiency of the array transmitter is improved by utilizing the coupling between antenna arrays to carry out active load modulation technology. technical background [0002] In a wireless communication system, the efficiency of a transmitter is an important indicator for evaluating the performance of a transmitter. Among all the technologies used to improve the linearity of the transmitter, the Doherty power amplifier technology is currently the most concerned and the most used technology. The Doherty power amplifier is also a high-efficiency power amplifier, which can maintain high efficiency within a certain range of power back-off, improve the working efficiency in the small power area, and have better linearity. The Doherty power amp...

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Problems solved by technology

Although these methods improve the bandwidth of the power amplifier, they also bring other challenges to the design of the power amplifier, such as the increase of the operating voltage and the increase of the loss of the output synthesis network.

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