CN-121618944-B - Power amplifier circuit with dynamic bias and radio frequency chip

CN121618944BCN 121618944 BCN121618944 BCN 121618944BCN-121618944-B

Abstract

The invention provides a power amplifier circuit with dynamic bias and a radio frequency chip, which comprise an input matching module, a power amplification module, a bias circuit module, an output matching module and a power detection module, wherein the output end of the bias circuit module is connected with the power amplification module and is used for providing corresponding bias voltage for the power amplification module according to the magnitude of control voltage input by the input end of the bias circuit module, the input end of the power detection module is connected with the output end of the power amplification module, the output end of the power detection module is connected with the input end of the bias circuit module, and the power detection module is used for collecting the output voltage of the output end of the power amplification module in real time and outputting the control voltage for representing the magnitude of the voltage through the output end of the power detection module according to the output voltage. The power amplifier circuit provided by the invention uses the self-adaptive active linear bias circuit, so that the linearity of the power amplifier can be effectively improved, and the power amplifier efficiency is improved.

Inventors

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Assignees

深圳飞骧科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260130

Claims (6)

1. A power amplifier circuit with dynamic bias, comprising an input matching module, a power amplifying module, a bias circuit module, an output matching module and a power detection module, wherein: the input end of the input matching module is used for accessing an external radio frequency signal, the output end of the input matching module is connected with the input end of the power amplification module, and the input matching module is used for providing input impedance matching for the power amplification module; the input end of the power amplification module is connected with the output end of the input matching module, the output end of the power amplification module is connected with the input end of the output matching module, and the power amplification module is used for carrying out power amplification treatment on the radio frequency signals; The output end of the bias circuit module is connected with the power amplification module and provides bias voltage for the power amplification module according to the control voltage input by the input end of the bias circuit module; the input end of the output matching module is connected with the output end of the power amplifying module and is used for providing output impedance matching for the power amplifying module, and the output end of the output matching module is used for outputting the amplified radio frequency signals; The input end of the power detection module is connected with the output end of the power amplification module, the output end of the power detection module is connected with the input end of the bias circuit module, the power detection module is used for collecting the signal power of the radio frequency signal output by the power amplification module in real time and outputting a control voltage for representing the power according to the signal power, and the control voltage is used for controlling the bias circuit module to realize the output of dynamic bias voltage; The power detection module comprises a first triode, a second triode, a first resistor, a second resistor, a third resistor, a first capacitor and a second capacitor, wherein: The first end of the first capacitor is used as an input end of the power detection module, and the second end of the first capacitor is connected with the emitter of the first triode; the emitter of the first triode is connected with the base electrode of the first triode, and the collector of the first triode is used as the output end of the power detection module; the first end of the second capacitor is connected with the collector electrode of the first triode, and the second end of the second capacitor is grounded; the first end of the first resistor is connected with the base electrode of the first triode, and the second end of the first resistor is used for being connected with a first external power supply voltage; the first end of the second resistor is connected with the base electrode of the first triode, and the second end of the second resistor is connected with the emitter electrode of the second triode; the emitter of the second triode is connected with the base electrode of the second triode, and the collector electrode of the second triode is grounded; the first end of the third resistor is connected with the collector electrode of the first triode, and the second end of the third resistor is grounded; The bias circuit module comprises a third triode, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a third capacitor and a fourth capacitor, wherein: The collector electrode of the third triode is used as the input end of the bias circuit module, the base electrode of the third triode is connected with the first end of the fourth resistor, and the emitter electrode of the third triode is connected with the first end of the sixth resistor; the second end of the fourth resistor is connected with the collector electrode of the third triode; The first end of the fifth resistor is connected with the base electrode of the third triode, and the second end of the fifth resistor is grounded; the second end of the sixth resistor is grounded; the first end of the seventh resistor is connected with the emitter of the third triode, and the second end of the seventh resistor is connected with the base electrode of the fourth triode; The collector of the fourth triode is connected with the collector of the third triode, and the emitter of the fourth triode is connected with the first end of the eighth resistor; The second end of the eighth resistor is used as the output end of the bias circuit module; The first end of the third capacitor is connected with the base electrode of the third triode, and the second end of the third capacitor is connected with the second end of the eighth resistor; The first end of the fourth capacitor is connected with the emitter of the fourth triode, and the second end of the fourth capacitor is connected with the second end of the eighth resistor.
2. The power amplifier circuit with dynamic bias of claim 1, wherein the power amplification module comprises a first stage power amplifier tube, a second stage power amplifier tube, and an inter-electrode matching circuit, wherein: the base electrode of the first-stage power amplifier is used as the input end of the power amplifier module, the collector electrode of the first-stage power amplifier is connected with the input end of the interelectrode matching circuit, and the emitter electrode of the first-stage power amplifier is grounded; the output end of the interelectrode matching circuit is connected with the base electrode of the second-stage power amplifier; The collector electrode of the second-stage power amplifying tube is used as the output end of the power amplifying module, and the emitter electrode of the second-stage power amplifying tube is grounded; And the output end of the bias circuit module is respectively connected with the base electrode of the first-stage power amplifier and the base electrode of the second-stage power amplifier.
3. The power amplifier circuit with dynamic bias of claim 2, wherein the collector of the first stage power amplifier is powered by a second external supply voltage and the collector of the second stage power amplifier is powered by a first external supply voltage.
4. The power amplifier circuit with dynamic bias of claim 3, wherein the power amplification module further comprises a first filter inductance, a first filter capacitance, a second filter inductance, and a second filter capacitance, wherein: The first end of the first filter inductor is connected with the collector electrode of the first-stage power amplifier, and the second end of the first filter inductor is used for being connected with the second external power supply voltage; the first end of the first filter capacitor is connected with the second end of the first filter inductor, and the second end of the first filter capacitor is grounded; The first end of the second filter inductor is connected with the collector electrode of the second-stage power amplifier, the second end of the second filter inductor is used for being connected with the first external power supply voltage, the first end of the second filter capacitor is connected with the second end of the second filter inductor, and the second end of the second filter capacitor is grounded.
5. The power amplifier circuit with dynamic bias of claim 1, wherein the third capacitance is a tunable capacitance.
6. A radio frequency chip comprising a power amplifier circuit with dynamic bias as claimed in any one of claims 1-5.

Description

Power amplifier circuit with dynamic bias and radio frequency chip Technical Field The invention is applicable to the field of radio frequency circuit design, and particularly relates to a power amplifier circuit with dynamic bias and a radio frequency chip. Background In a wireless communication system, a power amplifier is used as a final core device of a transmitting link, and the performance of the power amplifier directly determines the communication quality, coverage area and energy consumption level of the system. The core contradiction of the power amplifier design is that the efficiency and the linearity are balanced, especially in a 5G communication scenario, in order to improve the transmission rate and the spectrum efficiency, the system adopts non-constant envelope complex modulation techniques such as Quadrature phase shift keying (Quadrature PHASE SHIFT KEYING, QPSK), quadrature amplitude modulation (Quadrature Amplitude Modulation, QAM), quadrature frequency division multiplexing (Orthogonal Frequency Division Multiplexing, OFDM) and the like, and such signals generally have a large peak-to-average ratio. In general, the efficiency of a power amplifier increases with increasing power, but linearity is significantly deteriorated near saturation, so that a linearization technique is required to achieve both high efficiency and high linearity. The bias circuit of the existing power amplifier is generally divided into two types, namely a simple bipolar transistor bias circuit shown in figure 1, which is formed by serially connecting two resistors R and dividing the voltage, when the input power is increased, the diode clamping effect causes the reduction of the base-emitter direct current voltage and the increase of the current of the output stage power tube HBT, the reduction of transconductance, gain attenuation and phase distortion are caused, and the linearity is seriously influenced. Another active linear bias circuit shown in fig. 2 comprises transistors D1 and D2 connected in diode form, a capacitor C, and two resistors R, when the power of the input rf signal increases, part of the rf signal leaks into the bias circuit, the dc voltage drop Vbe1 of the base-emitter junction rectified by the transistor HBT2 decreases, and the base-emitter junction voltage of the power transistor HBT1 increases due to the decrease of the base-emitter junction voltage of the transistor HBT2, so that compensation is obtained, and the static operating point of the power amplifier is stabilized. The active linear bias can effectively stabilize the bias voltage of the power tube so as to improve the linearity of the power amplifier, but the static bias current of the fixed bias circuit is not different in a low-power state and a high-power state in the working process of the power amplifier, so that a large amount of direct current power is consumed and is not converted into useful radio frequency output power, the average efficiency of the whole system is lower, and the requirements of the wireless communication system on high efficiency and high linearity cannot be met. It is therefore desirable to provide a new power amplifier circuit that addresses the above-described issues. Disclosure of Invention The invention provides a power amplifier circuit with dynamic bias and a radio frequency chip, and aims to solve the problem that the power conversion efficiency of the conventional circuit design with fixed bias is difficult to meet the dynamic requirement. To solve the above technical problem, in a first aspect, the present invention provides a power amplifier circuit with dynamic bias, The power amplifier circuit comprises an input matching module, a power amplifying module, a biasing circuit module, an output matching module and a power detecting module, wherein: the input end of the input matching module is used for accessing an external radio frequency signal, the output end of the input matching module is connected with the input end of the power amplification module, and the input matching module is used for providing input impedance matching for the power amplification module; the input end of the power amplification module is connected with the output end of the input matching module, the output end of the power amplification module is connected with the input end of the output matching module, and the power amplification module is used for carrying out power amplification treatment on the radio frequency signals; The output end of the bias circuit module is connected with the power amplification module and provides bias voltage for the power amplification module according to the control voltage input by the input end of the bias circuit module; the input end of the output matching module is connected with the output end of the power amplifying module and is used for providing output impedance matching for the power amplifying module, and the output end of the output matching module is used for outputti