CN-114389551-B - Power amplifying circuit

Abstract

The invention provides a power amplifying circuit, which can properly perform gain dispersion without affecting the symmetry of a differential amplifying circuit. The power amplification circuit (100 c) includes differential amplification circuits (12 a, 12 b) for amplifying a high-frequency signal, a transformer (22) provided on the output side of the differential amplification circuits and having a primary winding and a secondary winding, and a dispersion circuit (41) which is an adjustment circuit connected to the midpoint (P22) of the primary winding of the transformer (22). A dispersion circuit (41) adjusts the bias (bias current or bias voltage) supplied to the differential amplifier circuit based on the power supply voltage controlled by the envelope of the high-frequency signal.

Inventors

• Hou Tengcong
• HONDA YURI
• Little string is better than oneself

Assignees

• 株式会社村田制作所

Dates

Publication Date

20260508

Application Date

20211019

Priority Date

20201020

Claims (7)

1. 1. A power amplifying circuit, comprising: a differential amplifier circuit that amplifies the high-frequency signal; a transformer arranged on the output side of the differential amplification circuit and having a primary winding and a secondary winding, and An adjusting circuit connected with the midpoint of the primary winding of the transformer, The adjustment circuit adjusts a bias current or a bias voltage supplied from a bias circuit to the differential amplification circuit based on a power supply voltage controlled in accordance with an envelope of the high-frequency signal.
2. 2. The power amplification circuit of claim 1, wherein, Comprises a cascaded differential amplifying circuit 1 and a cascaded differential amplifying circuit 2, The transformer is disposed between the differential amplifying circuit 1 and the differential amplifying circuit 2.
3. 3. The power amplification circuit of claim 2, wherein, The adjustment circuit adjusts the bias current or bias voltage supplied to the differential amplifier circuit described in the 1 st embodiment.
4. 4. The power amplification circuit of claim 2, wherein, The adjustment circuit adjusts the bias current or bias voltage supplied to the differential amplifier circuit described in the 2 nd.
5. 5. The power amplification circuit according to any one of claim 1 to claim 4, wherein, The high-frequency band elimination filter is electrically connected with the midpoint of the primary winding.
6. 6. The power amplification circuit according to any one of claim 1 to claim 4, wherein, The transformer is realized by a laminated substrate formed by laminating a plurality of layers, The primary winding and the secondary winding are arranged in mutually different layers of the laminated substrate.
7. 7. The power amplification circuit of claim 5, wherein, The transformer is realized by a laminated substrate formed by laminating a plurality of layers, The primary winding and the secondary winding are arranged in mutually different layers of the laminated substrate.

Description

Power amplifying circuit Technical Field The present invention relates to a power amplifying circuit. Background In recent years, with the transition to the 5 th generation mobile communication system, an increase in power consumption is alarming. As a technique for improving power efficiency, envelope tracking (ET: envelope Tracking) is used. Envelope tracking is a method of controlling the power supply voltage of a power amplifier circuit according to the amplitude level of an input signal. In envelope tracking, in order to obtain a high-efficiency characteristic, it is necessary to have a voltage dependence of gain (gain dispersion) so that the power supply potential becomes the optimum point of efficiency for each envelope. The gain dispersion means a difference in gain with respect to a change in power supply potential supplied to the transistor. A dispersion circuit (hereinafter, sometimes referred to as an adjustment circuit) is used as a circuit for adjusting gain dispersion to be an optimum point of efficiency. The power amplification circuit disclosed in patent document 1 is provided with an adjustment circuit. The adjustment circuit adjusts the amount of current of the bias current supplied to the amplification circuit based on a power supply voltage controlled in accordance with an envelope of the RF signal. Thereby, the adjustment circuit adjusts the range of gain dispersion. Patent document 2 describes a power amplifier circuit in which a variable power supply potential is supplied from an envelope tracking power supply circuit, and the lower the variable power supply potential is, the lower the bias current flowing to the base of a transistor is. In the power amplification circuit described in patent document 2, the lower the variable power supply potential is, the lower the gain of the transistor becomes, and thus the gain dispersion characteristic can be improved. Therefore, the power amplification circuit described in patent document 2 can suppress an increase in gain at the time of low power supply potential, and can equalize the gain with that at the time of high power supply potential. Prior art literature Patent literature Patent document 1 Japanese patent laid-open No. 2020-65244 Patent document 2 Japanese patent application laid-open No. 2018-195954 However, in a power amplification circuit including a differential amplification circuit, if gain dispersion is achieved, there is a concern that symmetry of the differential amplification circuit may be affected, and there is room for improvement. Disclosure of Invention Problems to be solved by the invention The present invention has been made in view of the above circumstances, and an object thereof is to provide a power amplification circuit capable of appropriately performing gain dispersion without affecting symmetry of a differential amplification circuit. Means for solving the problems The power amplification circuit includes a differential amplification circuit that amplifies a high-frequency signal, a transformer provided on an output side of the differential amplification circuit and having a primary winding and a secondary winding, and an adjustment circuit connected to a midpoint of the primary winding of the transformer, wherein the adjustment circuit adjusts a bias current or a bias voltage supplied to the differential amplification circuit based on a power supply voltage controlled in accordance with an envelope of the high-frequency signal. Effects of the invention According to the present invention, the gain dispersion can be appropriately performed without affecting the symmetry of the differential amplifier circuit. Drawings Fig. 1 is a diagram showing a configuration of a transmission circuit including a power amplification circuit according to embodiment 1. Fig. 2 is a diagram showing a power amplifying circuit of comparative example 1. Fig. 3 is a diagram showing a configuration example of the dispersion circuit and the bias circuit. Fig. 4 is a diagram illustrating the operation characteristics of the dispersion circuit. Fig. 5 is a diagram illustrating the operation characteristics of the dispersion circuit. Fig. 6 is a diagram showing a power amplifying circuit based on comparative example 2. Fig. 7 is a diagram showing a power amplification circuit according to embodiment 2. Fig. 8 is a diagram showing a more specific configuration example of the power amplification circuit according to embodiment 2. Fig. 9 is a diagram showing a power amplification circuit according to embodiment 3. Fig. 10 is a diagram showing a power amplification circuit according to embodiment 4. Fig. 11 is a diagram showing a power amplification circuit according to embodiment 5. Fig. 12 is a diagram showing an example of arrangement on a substrate of the power amplification circuit. Fig. 13 is a diagram showing an example of arrangement on a substrate of the power amplification circuit. Fig. 14 is a diagram showing a power amplification c