Selection circuit and amplifier comprising same

Abstract

In order to solve the problem that the efficiency of the existing power amplifier changes along with the output power, the invention relates to a selection circuit and an amplifier comprising the selection circuit; the selection circuit comprises at least one power divider phase shift module, a first transmission line module, a second transmission line module, a third transmission line module, a first switch module and a second switch module, wherein each power divider phase shift module is provided with a first input end, a second input end, a first output end and a second output end, and is used for dividing signals which are input into the first input end and / or the second input end into two paths of orthogonal signals with constant amplitude and outputting the signals from the first output end and the second output end; each power divider phase shift module also comprises at least one 3dB 90-degree bridge; the first transmission line module is used for connecting the first input end and a first input of the selection circuit; the second transmission line module is used for connecting the second input end and a second input of the selection circuit; the third transmission line module is used for connecting the first output end and the second input end; the first switch module is used for enabling the second input to be in ground connection; and the second switch module is used for enabling the first output end to be in ground connection. After the selection circuit is adopted, the power loss can be reduced.

Description

technical field [0001] The invention relates to a power device, in particular to a selection circuit capable of reducing power loss and an amplifier comprising the selection circuit. Background technique [0002] The efficiency of a power amplifier always decreases as its output power is less than its rated power. In order to optimize the efficiency of the power amplifier according to the change of the output power, when the output power of the power amplifier is lower than its rated power, the common method is that the reduced drain / collector voltage and current somehow compensate its efficiency deterioration. However, since the performance of the power amplifier will limit the degree of reduction of the bias voltage and current, this method cannot completely solve the above problems. [0003] Currently, commonly used Doherty Power Amplifiers (DPAs), especially asymmetric DPAs and multistage DPAs, can maintain acceptable PA efficiencies in the presence of high back-off pow...

AI Technical Summary

Problems solved by technology

However, DPA also has the same problem as above, that is, the efficiency of DPA will continue to deteriorate as the output power is less than the rated power, and the design difficulty (high fallback) and cost (multi-channel DPA) also make it difficult to solve the above problems.

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