Circuit for reducing memory effect of radio-frequency power amplifier, output circuit of radio-frequency power amplifier, and radio-frequency power amplifier

Abstract

The embodiment of the invention provides a circuit for reducing the memory effect of a radio-frequency power amplifier, an output circuit of the radio-frequency power amplifier, and the radio-frequency power amplifier. The harmonic impedance of the radio-frequency power amplifier can be controlled in an optimal range while the memory effect of the radio-frequency power amplifier is reduced. The circuit for reducing the memory effect of the radio-frequency power amplifier comprises a first micro-strip line, a second micro-strip line, a first capacitor and a second capacitor, wherein one end of the first micro-strip line is connected with one end of the second micro-strip line; one end of the first capacitor is connected with one end of the first micro-strip line; the other end of the first capacitor is grounded; one end of the second capacitor is connected with the other end of the second micro-strip line; the other end of the second capacitor is grounded; for the fundamental impedance and the envelop impedance of the radio-frequency power amplifier, the first capacitor is in an open-circuit state; and, for the envelop impedance of the radio-frequency power amplifier, the second capacitor is in a short-circuiting state.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a circuit for reducing the memory effect of a power amplifier, a power amplifier output circuit and a power amplifier. Background technique [0002] In a wireless communication device, a radio frequency power amplifier (hereinafter referred to as a power amplifier) ​​as a core component is particularly important. In the practical application of the power amplifier, the memory effect of the power amplifier is an important factor affecting the performance of the power amplifier, and the memory effect of the power amplifier is closely related to the video bandwidth (English: videobandwidth, abbreviation: VBW) of the power amplifier. When the instantaneous bandwidth of the RF signal is relatively wide, it is usually necessary to increase the VBW to reduce the memory effect of the power amplifier. From the perspective of frequency domain, the memory effect of power amplifier i...

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Problems solved by technology

[0004] However, the above as figure 1 Although the circuit structure shown can reduce the memory effect of the power amplifier, and at the same time ensure that the fundamental wave impedance of the power amplifier is basically not affected, but for harmonic impedance, such as the second harmonic impedance, the length of the microstrip line 1 is 0.5*λg1, Among them, λg1=0.5*λg0; according to circuit theory, since the length of the microstrip line is 0.5*λg1, the harmonic impedance will be periodic, so when point A is short-circuited, point B is still short-circuited

Therefore, the circuit cannot control the harmonic impedance of the power amplifier, so that the harmonic impedance of the power amplifier cannot be in the optimal range.

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