A circuit for improving the magnitude of dynamic error vector

Abstract

The present invention relates to the technical field of radio frequency chip power amplifiers, and in particular, to a circuit for improving the dynamic error vector amplitude. The circuit comprises: a thermal sensing circuit, a bias adjustment circuit, a bias circuit, an RF power tube, a first capacitor, and a second capacitor. By adjusting the relative positions of the thermal sensing circuit and the RF power tube on the chip, the thermal sensing transistor can sense the change in the temperature of the RF transistor, and after converting it into a voltage change according to a certain ratio, the change is transmitted to the bias adjustment circuit. The bias adjustment circuit amplifies the change signal after receiving it, and the amplified change signal is injected into the RF power tube through the bias circuit, forming a negative feedback to compensate for the gain fluctuation caused by the temperature change of the RF power tube, thereby achieving the purpose of improving the dynamic error vector amplitude.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency chip power amplifiers, and in particular to a circuit for improving a dynamic error vector amplitude. Background Art

[0002] IEEE 802.11be achieves a transmission rate of up to 30Gb / s by using wider channels, higher adjustment schemes and multi-link operations, which is more than four times that of IEEE 802.11ax. The high-order modulation method of 4096QAM it adopts also places extremely stringent requirements on the quality of the signal. Dynamic error vector (DEVM) is an indicator of signal quality in the field of wireless communication technology, especially in WIFI. The smaller the value of the dynamic error vector, the higher the signal quality. For IEEE 802.11ax, DEVM meets the -43dB condition, and the output power is generally around 18-22dBm, while IEEE 802.11be has higher requirements for the DEVM of the signal. The introduction of various new wireless communication technologies has posed huge challenges to the hardware system of wireless communication. The pursuit of high output power under high-quality signals is an important topic of wireless communication hardware systems.

[0003] In the WIFI system, when the power tube in the power amplifier is turned on and off, the temperature of the transistor will change over time. The change in transistor temperature will cause the change in its gain, which will lead to the deterioration of the dynamic error vector. For application scenarios with high requirements for signal quality such as IEEE 802.11be, the gain fluctuation needs to be accurately controlled within 0.1dB, so the deterioration of DEVM caused by the temperature change of the power tube is a problem that cannot be ignored. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] Therefore, an object of the present invention is to provide a circuit for improving the dynamic error vector amplitude.

[0006] In order to achieve the above object, the technical solution of the present invention provides a circuit for improving the dynamic error vector amplitude.

[0007] It includes: a thermal sensing circuit, a bias adjustment circuit, a bias circuit, an RF power tube, a first capacitor and a second capacitor;

[0008] Wherein, the bias adjustment circuit includes a third resistor and a first transistor, and the thermal sensing circuit includes a thermal sensing transistor and a first resistor;

[0009] The RF input is connected to one end of the first capacitor, and the other end of the first capacitor is connected to the base of the RF power tube and the first end of the bias circuit; the collector of the RF power tube is connected to the external power supply voltage VCC2 and one end of the second capacitor, the other end of the second capacitor is connected to the RF output end, and the emitter of the RF power tube is grounded; the first end of the bias circuit is connected to the collector of the first transistor in the bias adjustment circuit and one end of the third resistor, the emitter of the first transistor is grounded, the base of the first transistor is connected to the collector of the thermal sensing transistor, and the other end of the third resistor is connected to the external power supply voltage VEN2; the second end of the bias circuit is connected to the external power supply voltage VCC1;

[0010] One end of the first resistor is connected to the collector of the thermal sensing transistor, the other end of the first resistor is connected to the external power supply voltage VEN1, the emitter of the thermal sensing transistor is grounded, and the base of the thermal sensing transistor is connected to the collector.

[0011] Furthermore, the bias adjustment circuit also includes a third resistor, one end of the third resistor is connected to the base of the first transistor, and the other end of the second resistor is connected to the collector of the thermal sensing transistor.

[0012] Further, the bias circuit includes a second transistor, a third transistor, a fourth transistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor;

[0013] The base of the fourth transistor is connected to the collector of the first transistor, and the collector of the fourth transistor is connected to the external power supply voltage VCC1;

[0014] One end of the eighth resistor is connected to the base of the RF power tube, the other end of the eighth resistor is connected to one end of the seventh resistor and the emitter of the fourth transistor, the other end of the seventh resistor is connected to one end of the fifth resistor, one end of the sixth resistor and the base of the second transistor, the other end of the sixth resistor is grounded, the other end of the fifth resistor is connected to the emitter of the third transistor, the base of the third transistor is connected to one end of the fourth resistor, and the other end of the fourth resistor is connected to the collector of the second transistor and the base of the fourth transistor; the collector of the third transistor is connected to the external power supply voltage VCC1.

[0015] Furthermore, by adjusting the relative positions of the thermal sensing transistor and the RF power tube on the chip, the thermal sensing transistor can sense the temperature change of the RF power tube and convert the temperature change of the RF power tube into a voltage change.

[0016] Beneficial effects of the present invention:

[0017] The advantage of the circuit for improving the dynamic error vector amplitude of the present invention is that the temperature change of the RF power tube is converted into a voltage change by adjusting the relative position of the thermal sensing circuit and the RF power tube on the chip. After obtaining the change of the RF power tube, the thermal sensing circuit injects the change into the bias adjustment circuit, and the bias adjustment circuit injects the change generated by the thermal sensing circuit into the RF power transistor after amplification, thereby improving the dynamic EVM of the power tube.

[0018] Additional aspects and advantages of the invention will become apparent from the following description, or may be learned by practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram showing the principle of improving the dynamic error vector amplitude of the present invention is shown;

[0020] Figure 2 A schematic diagram showing the structure of a circuit for improving the dynamic error vector amplitude according to embodiment 1 of the present invention is shown;

[0021] Figure 3 A schematic diagram of a circuit structure for improving the dynamic error vector amplitude provided by Embodiment 2 of the present invention is shown;

[0022] Figure 4 A schematic diagram showing the effect of a circuit structure for improving dynamic error vector amplitude on gain adjustment according to the present invention is shown; DETAILED DESCRIPTION

[0023] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0024] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0025] Figure 1 The schematic diagram of the principle of improving the dynamic error vector amplitude is shown. When the RF power tube is turned on and off, the temperature of the RF power tube will also change with time. The change of transistor temperature will cause the change of its gain, thereby affecting the dynamic error vector amplitude.

[0026] The present invention adjusts the relative positions of the thermal sensing circuit and the RF power tube on the chip so that the thermal sensing circuit can sense the temperature change of the RF power tube, and after converting it into a voltage change according to a certain ratio, transmit the voltage change to the bias adjustment circuit. The bias adjustment circuit amplifies the voltage change after receiving it, and the amplified voltage change signal is injected into the RF power tube through the bias circuit, forming a negative feedback to compensate for the gain fluctuation caused by the temperature change of the RF power tube, thereby achieving the purpose of improving the dynamic error vector amplitude.

[0027] Embodiment 1, Figure 2 A basic structural diagram of a circuit for improving the dynamic error vector amplitude of the present invention is shown, which includes: a thermal sensing circuit, a bias adjustment circuit, a bias circuit, an RF power tube, a first capacitor and a second capacitor;

[0028] One end of the first capacitor is connected to the RF input, and the other end is connected to the base of the RF power tube and one end of the bias circuit. The collector of the RF power tube is connected to the external power supply voltage VCC2 and one end of the second capacitor. The other end of the second capacitor is connected to the RF output, and the emitter of the RF power tube is grounded. One end of the bias circuit is connected to one end of the bias adjustment circuit, and the other end of the bias circuit is connected to the external power supply voltage VCC1, and the other end of the bias adjustment circuit is connected to the thermal sensing circuit.

[0029] The bias adjustment circuit includes a first transistor and a third resistor, one end of the third resistor is connected to an external power supply voltage VEN2, the other end of the third resistor is connected to the collector of the first transistor and the bias circuit, the emitter of the first transistor is grounded; the base of the first transistor is connected to the thermal sensing circuit;

[0030] The thermal sensing circuit includes a thermal sensing transistor and a first resistor, one end of the first resistor is connected to an external power supply voltage VEN1, the other end of the first resistor is connected to the base of the first transistor and the collector of the thermal sensing transistor, the emitter of the thermal sensing transistor is grounded, and the base of the thermal sensing transistor is connected to the collector.

[0031] Among them, the role of the thermal sensing transistor is to sense the temperature change of the RF power tube and convert the temperature information into information such as voltage for transmission. This conversion can be carried out in a variety of ways. The role of the bias adjustment circuit is to amplify the temperature information obtained by the thermal sensing transistor and pass it to the bias circuit. The role of the bias circuit is to provide a stable DC bias for the RF power tube on the one hand, and on the other hand, to convert the temperature information obtained in the power adjustment circuit into a negative feedback effect and pass it to the RF power tube for a negative feedback adjustment. Thereby, the gain fluctuation of the RF power tube to temperature change is improved, and the dynamic error vector amplitude of the power amplifier is improved.

[0032] Example 2, in order to better illustrate the present invention, Figure 3 A schematic diagram of a circuit structure for improving the dynamic error vector amplitude of the present invention is shown, which includes: a thermal sensing circuit, a bias adjustment circuit, a bias circuit, an RF power tube, a first capacitor and a second capacitor;

[0033] One end of the first capacitor is connected to the RF output, and the other end is connected to the base of the RF power tube and one end of the bias circuit. The collector of the RF power tube is connected to the external power supply voltage VCC2 and one end of the second capacitor, and the other end of the second capacitor is connected to the RF output. One end of the bias circuit is connected to one end of the bias adjustment circuit, and the other end of the bias adjustment circuit is connected to the thermal sensing circuit.

[0034] The thermal sensing circuit includes a thermal sensing transistor and a first resistor, and the bias adjustment circuit includes a third resistor, a first transistor, and a second resistor, wherein the base of the thermal sensing transistor and the collector of the thermal sensing transistor, one end of the first resistor, and one end of the second resistor in the bias adjustment circuit are connected, the emitter of the thermal sensing transistor is grounded, the other end of the first resistor is connected to the external power supply voltage VEN1, and the other end of the second resistor is connected to the base of the first transistor. The thermal sensing transistor is connected in the manner of a diode, and the change in the temperature of the RF power tube is successfully converted into a change in voltage.

[0035] The emitter of the first transistor is grounded. The collector of the first transistor is connected to one end of the third resistor; the other end of the third resistor is connected to the external power supply voltage VEN2, and the bias adjustment circuit adopts a common emitter amplifier circuit to amplify the changes generated by the thermal inductive circuit.

[0036] The bias circuit includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a second transistor, a third transistor and a fourth transistor. One end of the eighth resistor is connected to the base of the RF power tube, the other end of the eighth resistor is connected to one end of the seventh resistor and the emitter of the fourth transistor, and the other end of the seventh resistor is connected to one end of the fifth resistor, one end of the sixth resistor and the base of the second transistor. The other end of the sixth resistor is grounded. The other end of the fifth resistor is connected to the emitter of the third transistor. The collector of the fourth transistor is connected to the external power supply voltage VCC1 and the collector of the third transistor, and the base of the fourth transistor is connected to the collector of the first transistor in the bias adjustment circuit, one end of the fourth resistor and the collector of the second transistor. The emitter of the second transistor is grounded. The other end of the fourth resistor is connected to the base of the third transistor.

[0037] On the one hand, the bias circuit provides a stable DC bias for the RF power tube, and on the other hand, it converts the temperature information obtained in the power adjustment circuit into a negative feedback effect and transmits it to the RF power tube for a negative feedback adjustment.

[0038] The effect of the present invention on gain adjustment is as follows Figure 4 As shown. It can be seen that the method for improving the dynamic error vector amplitude proposed by the present invention has an excellent effect on the gain adjustment, and a gain fluctuation of 0.3 can be achieved at 20usec, and a gain fluctuation within 0.03 can be achieved after 50usec. Therefore, it can be seen that the present invention can achieve a good improvement on the fluctuation of the RF power tube gain caused by temperature, which is very helpful to improve the dynamic error vector amplitude.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A circuit for increasing dynamic error vector magnitude, characterized in that: include: A thermal sensing circuit, a bias adjustment circuit, a bias circuit, an RF power tube, a first capacitor, and a second capacitor; Wherein, the bias adjustment circuit includes a third resistor and a first transistor, and the thermal sensing circuit includes a thermal sensing transistor and a first resistor; The RF input is connected to one end of the first capacitor, and the other end of the first capacitor is connected to the base of the RF power tube and one end of the bias circuit; the collector of the RF power tube is connected to the external power supply voltage VCC2 and one end of the second capacitor, the other end of the second capacitor is connected to the RF output end, and the emitter of the RF power tube is grounded; one end of the bias circuit is connected to the collector of the first transistor in the bias adjustment circuit and one end of the third resistor, the emitter of the first transistor is grounded, the base of the first transistor is connected to the collector of the thermal sensing transistor, and the other end of the third resistor is connected to the external power supply voltage VEN2; the other end of the bias circuit is connected to the external power supply voltage VCC1; One end of the first resistor is connected to the collector of the thermal sensing transistor, the other end of the first resistor is connected to the external power supply voltage VEN1, the emitter of the thermal sensing transistor is grounded, and the base of the thermal sensing transistor is connected to the collector; The bias adjustment circuit further includes a second resistor, one end of the second resistor is connected to the collector of the thermal sensing transistor, and the other end of the second resistor is connected to the base of the first transistor; The bias circuit includes a second transistor, a third transistor, a fourth transistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor; The base of the fourth transistor is connected to the collector of the first transistor, and the collector of the fourth transistor is connected to the external power supply voltage VCC1; One end of the eighth resistor is connected to the base of the RF power tube, the other end of the eighth resistor is connected to one end of the seventh resistor and the emitter of the fourth transistor, the other end of the seventh resistor is connected to one end of the fifth resistor, one end of the sixth resistor and the base of the second transistor, the other end of the sixth resistor is grounded, the other end of the fifth resistor is connected to the emitter of the third transistor, one end of the fourth resistor is connected to the collector of the second transistor and the base of the fourth transistor; the base of the third transistor is connected to the other end of the fourth resistor, and the collector of the third transistor is connected to the external power supply voltage VCC1; By adjusting the relative positions of the thermal sensing transistor and the RF power tube on the chip, the thermal sensing transistor can sense the temperature change of the RF power tube and convert the temperature change of the RF power tube into a voltage change.

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