Radio frequency PA adaptive linearization and temperature insensitive biasing circuit applied to GaAs process

Abstract

The invention provides a radio frequency PA self-adaptive linearization and temperature insensitive biasing circuit applied to a GaAs process, which comprises a transistor HBT1, a transistor HBT0 and a self-adaptive linearization biasing circuit for realizing rectification and compensation by utilizing a base-aggregation diode of a triode, a forward bias base-aggregation diode of the transistor HBT1, a resistor R1 and a capacitor C1 form a base bias circuit of the transistor HBT0; the self-adaptive linearization biasing circuit is realized through the mirror current source, and meanwhile, the characteristics of the biasing circuit are combined, and a temperature compensation resistor and a frequency compensation capacitor are added in the biasing circuit, so that the defects that the conventional circuit is insensitive to temperature compensation and the compensation bandwidth in the working frequency of the PA is insufficient are overcome.

Description

Technical Field

[0001] The invention relates to the technical field of bias circuits, and in particular to a radio frequency PA adaptive linearization and temperature-insensitive bias circuit applied to a GaAs process. Background Art

[0002] In the design of PA, in order to achieve high gain and high linearity, it is necessary to design a suitable operating point for the circuit, which requires the design of a suitable bias circuit. Unlike small signal power amplifier devices such as LNA, the output power of the power amplifiers of 4G, 5G and WiFi6 is relatively large. Due to the heating of the device itself, the characteristics of the HBT in the PA will change, affecting the reliability of the PA, and affecting its linearity and gain; at the same time, due to the discrete type of the device itself, the problem will be magnified in the mass production stage, and the gain and linearity of some devices at high and low temperatures will be significantly worse than those at room temperature, and cannot meet the use requirements. Due to the limitations of circuit characteristics, some linear compensation circuits currently used for GaAs PA cannot achieve the optimal compensation bandwidth and temperature response.

[0003] With the rapid development of wireless communication technology, 4G / 5G and WIFI6 systems have higher requirements for the performance of RF devices, especially PA. PA performance mainly includes gain, power efficiency, and linearity. In LTE and WiFi6 applications, linearity is one of the most important indicators, which determines the transition of RF PA from the original SiGe process to GaAs. The output current of GaAs HBT is exponentially related to the input voltage, and its electron mobility is 5 to 6 times greater than that of silicon, the current density is higher, and the transconductance is much higher than that of CMOS. Therefore, in high-frequency and high-speed applications, GaAs performance is significantly better than SiGe.

[0004] The existing technology mainly ensures that the gain compression and phase distortion of the PA output are not affected when the input power increases by compensating the input bias point; at the same time, based on the characteristics of the HBT and diode in the bias circuit, the changes in their own characteristics when the temperature changes will negatively feedback the bias of HBT0, thus achieving a certain degree of temperature compensation. However, based on the characteristics of this circuit, its temperature compensation is not sensitive enough; and the bandwidth of HBT0 compensation is not large enough. In the use scenarios of WiFi 6 and 5G high bandwidth, the consistency of PA within the full bandwidth will be relatively poor. Summary of the invention

[0005] The technical problem solved by the present invention is to provide a radio frequency PA adaptive linearization and temperature-insensitive bias circuit applied to GaAs process, so as to solve the problems raised in the above background technology.

[0006] The technical problem solved by the present invention is achieved by adopting the following technical scheme: an adaptive linear and temperature-insensitive bias circuit of a radio frequency PA applied to a GaAs process, comprising: a transistor HBT1, a transistor HBT0, an adaptive linear bias circuit that uses a base-collector diode of a triode to realize rectification and compensation, and a base-collector diode of the transistor HBT1 that is forward biased, a resistor R1, and a capacitor C1 that form a base bias circuit of the transistor HBT0;

[0007] Furthermore, when the input power of the temperature-insensitive bias circuit increases, the DC current rectified by the base-collector diode of the transistor HBT1 increases, and the DC voltage across the junction decreases, thereby compensating for the base-emitter voltage of the transistor HBT0. The increased DC current also enhances the ability to drive the transistor HBT0, thereby suppressing gain compression. Since the base-emitter junction conductance of HBT0 increases with the increase of input power under large signal conditions, and the reduced base-collector voltage of the transistor HBT1 reduces the conductance of the transistor HBT1, the change in the conductance of the transistor HBT0 is compensated, thereby suppressing phase distortion.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention realizes an adaptive linearization bias circuit through a mirror current source, and at the same time, in combination with the characteristics of the bias circuit, adds a temperature compensation resistor and a frequency compensation capacitor therein to solve the shortcomings of the previous circuit being insensitive to temperature compensation and insufficient compensation bandwidth within the PA operating frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the circuit structure of the present invention.

[0010] Figure 2 It is a test schematic diagram of the present invention. DETAILED DESCRIPTION

[0011] In order to make the technical means for realizing the present invention, the creative features, the objectives and effects to be achieved easy to understand, the present invention is further explained below in conjunction with specific diagrams. In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection, or an integral connection can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be internal communication between two elements.

[0012] like Figure 1 , Figure 2As shown, an adaptive linear and temperature-insensitive bias circuit for a radio frequency PA applied to a GaAs process includes: a transistor HBT1, a transistor HBT0, an adaptive linear bias circuit that uses a base-collector diode of a triode to realize rectification and compensation, and a forward-biased base-collector diode of the transistor HBT1, a resistor R1, and a capacitor C1 form a base bias circuit of the transistor HBT0;

[0013] When the input power of the temperature-insensitive bias circuit increases, the DC current rectified by the base-collector diode of the transistor HBT1 increases, and the DC voltage across the junction decreases, thereby compensating for the base-emitter voltage of the transistor HBT0. The increased DC current also enhances the ability to drive the transistor HBT0, thereby suppressing gain compression. Since the base-emitter junction conductance of HBT0 increases with the increase of input power under large signal conditions, the reduced base-collector voltage of the transistor HBT1 reduces the conductance of the transistor HBT1, thereby compensating for the change in the conductance of the transistor HBT0, thereby suppressing phase distortion.

[0014] The present invention realizes an adaptive linearized bias circuit through a mirror current source, and combines the characteristics of the bias circuit to add a temperature compensation resistor and a frequency compensation capacitor therein to solve the shortcomings of the previous circuit being insensitive to temperature compensation and insufficient compensation bandwidth within the PA operating frequency.

[0015] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A radio frequency PA adaptive linearization and temperature insensitive bias circuit applied to GaAs process, characterized in that: include: Transistor HBT1 and transistor HBT0 use the base-collector diode of the triode to realize the adaptive linear bias circuit for compensation. The forward biased base-collector diode of transistor HBT1, resistor R1 and capacitor C1 form the base bias circuit of transistor HBT0.

2. The RF PA adaptive linearization and temperature-insensitive bias circuit for GaAs process according to claim 1, characterized in that: When the input power of the temperature-insensitive bias circuit increases, the DC current rectified by the base-collector diode of the transistor HBT1 increases, and the DC voltage across the junction decreases, thereby compensating for the base-emitter voltage of the transistor HBT0. The increased DC current also enhances the ability to drive the transistor HBT0, thereby suppressing gain compression. Since the base-emitter junction conductance of HBT0 increases with the increase of input power under large signal conditions, the reduced base-collector voltage of the transistor HBT1 reduces the conductance of the transistor HBT1, thereby compensating for the change in the conductance of the transistor HBT0, thereby suppressing phase distortion.

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