Output power detection circuit and detection method of transmitter

Abstract

The invention provides an output power detection circuit and detection method of a transmitter, the detection circuit comprises a sampling module, an amplification module and a signal processing module, the transmitter comprises a power amplifier, the sampling module is used for sampling a sampling voltage between a power supply end and a power supply input end of the power amplifier, the sampling voltage is amplified through the amplification module to obtain amplified voltage, and analog-to-digital conversion and signal analysis are performed on the amplified voltage through the signal processing module to obtain output power. According to the detection circuit provided by the invention, the output power can be obtained only by collecting the voltage drop between the power supply input end and the power supply end of the power amplifier and then carrying out amplification, analog-to-digital conversion and signal analysis on the voltage drop, so that the detection of the output power of the power amplifier is realized by detecting the power supply current of the power amplifier; in the output power detection process, a directional coupler is not needed, power loss does not exist, the reliability of the transmitter is improved, a radio frequency detector is not needed, and the detection cost is greatly reduced.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a transmitter output power detection circuit and detection method. Background Technology

[0002] The transmitter processes and transforms the raw information to be transmitted, enabling it to be effectively radiated into free space through the antenna. It is an irreplaceable component in the field of wireless communication. The power amplifier (PA), as a core component in the transmitter link, is known as the "power source" of the transmitter. The power amplifier amplifies the radio frequency (RF) signal, allowing it to be effectively radiated through the antenna, thus achieving long-distance transmission. Output power is a core parameter of the transmitter; therefore, detecting the output power of the power amplifier is particularly important.

[0003] Currently, the output power detection circuit of a power amplifier mainly consists of high-power directional couplers and radio frequency detectors. Firstly, high-power directional couplers introduce power loss, leading to a reduction in the transmitter's output power. Secondly, because directional couplers operate with high-power signals for extended periods, the signal failure rate accumulates over time, reducing reliability. Thirdly, directional couplers and radio frequency detectors are costly and bulky.

[0004] Therefore, how to provide a transmitter power detection circuit that is lossless, highly reliable, and low in cost is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] This application provides a transmitter output power detection circuit and detection method to solve the problems of high power loss, low reliability and high cost of the above-mentioned transmitter output power detection circuit.

[0006] In a first aspect, this application provides an output power detection circuit for a transmitter, the transmitter including a power amplifier, the detection circuit comprising: The sampling module is used to sample the voltage between the power supply terminal and the power input terminal of the power amplifier to obtain the sampled voltage; An amplification module, whose input is connected to the sampling module, amplifies the sampled voltage to obtain an amplified voltage; The signal processing module, whose input is connected to the amplification module, performs analog-to-digital conversion and signal analysis on the amplified voltage to obtain the output power.

[0007] In one embodiment of this application, the sampling module includes a sampling resistor, the first end of which is connected to the power supply terminal, and the second end of which is connected to the power input terminal of the power amplifier.

[0008] In one embodiment of this application, the resistance value of the sampling resistor is in the milliohm range.

[0009] In one embodiment of this application, the amplification module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first operational amplifier, a second operational amplifier, and a third operational amplifier. The inverting input terminal of the first operational amplifier is connected to its output terminal via the first resistor. The output terminal of the first operational amplifier is connected to its inverting input terminal via the second resistor. The inverting input terminal of the second operational amplifier is also connected to its output terminal via the third resistor. The inverting input terminal of the third operational amplifier is connected to its output terminal via the fourth resistor. The output terminal of the third operational amplifier is connected to its non-inverting input terminal via the fifth resistor. The non-inverting input terminal of the second operational amplifier is grounded via the sixth resistor. The first terminal of the seventh resistor is connected to the inverting input terminal of the first operational amplifier, and the second terminal of the seventh resistor is connected to the inverting input terminal of the third operational amplifier. The non-inverting input terminals of the first and third operational amplifiers are the input terminals of the amplification module, and the output terminal of the second operational amplifier is the output terminal of the amplification module.

[0010] In one embodiment of this application, the resistance values ​​of the first resistor and the fourth resistor are equal, the resistance values ​​of the second resistor and the fifth resistor are equal, and the resistance values ​​of the third resistor and the sixth resistor are equal.

[0011] In one embodiment of this application, the signal processing module includes an analog-to-digital conversion unit and an analysis unit. The input terminal of the analog-to-digital conversion unit is connected to the amplification module, which samples the amplified voltage and performs analog-to-digital conversion on the amplified voltage to obtain a digital signal. The input terminal of the analysis unit is connected to the analog-to-digital conversion unit, which performs data mapping on the digital signal based on a preset calibration mapping relationship to obtain the output power.

[0012] Secondly, this application provides a method for detecting the output power of a transmitter, which is applied to the output power detection circuit of the transmitter as described above, including: Obtain the sampled voltage; The sampled voltage is amplified, and the amplified voltage is subjected to analog-to-digital conversion and signal analysis to obtain the output power.

[0013] In one embodiment of this application, before acquiring the sampling voltage, the method further includes: controlling the power detection circuit to be in a calibration state, and acquiring multiple output powers and their corresponding sampling voltages; amplifying the multiple sampling voltages and converting them into multiple digital signals; establishing a calibration mapping relationship between the multiple digital signals and the multiple output powers, and storing the calibration mapping relationship in a signal processing module.

[0014] In one embodiment of this application, the sampled voltage is amplified, and the amplified voltage is subjected to analog-to-digital conversion and signal analysis to obtain output power, including: amplifying the sampled voltage to obtain an amplified voltage; performing analog-to-digital conversion on the amplified voltage to obtain a digital signal; and performing data mapping on the digital signal based on the calibration mapping relationship to obtain the output power.

[0015] The beneficial effects of this application are as follows: This application provides an output power detection circuit and method for a transmitter. The detection circuit includes a sampling module, an amplification module, and a signal processing module. The transmitter includes a power amplifier. The sampling module samples the voltage between the power supply terminal and the power input terminal of the power amplifier. The amplification module amplifies the sampled voltage to obtain an amplified voltage. The signal processing module performs analog-to-digital conversion and signal analysis on the amplified voltage to obtain the output power. The detection circuit provided by this application only needs to collect the voltage drop between the power input terminal and the power supply terminal of the power amplifier, and then amplify, convert, and analyze the voltage drop to obtain the output power. This achieves the detection of the power amplifier output power by detecting the power amplifier supply current. No directional coupler is needed during the output power detection process, eliminating power loss and improving the reliability of the transmitter. Furthermore, no radio frequency detector is required, significantly reducing detection costs and space requirements. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0017] In the attached diagram: Figure 1 This is a block diagram of the transmitter output power detection circuit provided in the embodiments of this application; Figure 2 This is a schematic diagram showing the specific connection relationship of the sampling module of the transmitter provided in the embodiments of this application; Figure 3 This is a schematic diagram of the specific structure of the amplification module provided in the embodiments of this application.

[0018] Figure reference numerals: 110-Power amplifier; 120-Sampling module; 130-Amplification module; 140-Signal processing module; Vs-Sampling voltage; Vc-Amplification voltage; Pout-Output power. Detailed Implementation

[0019] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0020] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present application. However, it will be apparent to those skilled in the art that embodiments of the present application may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present application.

[0022] The inventors discovered that the transmitter processes and transforms the raw information to be transmitted, enabling it to be effectively radiated into free space through the antenna, making it an irreplaceable component in the field of wireless communication. The power amplifier (PA), as a core component in the transmitter link, is known as the "power source" of the transmitter. The power amplifier amplifies the radio frequency signal, and then effectively radiates the amplified radio frequency signal through the antenna, thereby achieving long-distance transmission. Output power is a core parameter of the transmitter, making the detection of the power amplifier's output power particularly important.

[0023] Currently, the output power detection circuit of a power amplifier mainly consists of a high-power directional coupler and an RF detector. The conventional power detection circuit is located on the transmitter's signal transmission link. The directional coupler is typically located at the output of the isolator, while the RF detector and other circuits are located at the output of the directional coupler. The directional coupler couples the output power, the RF detector detects the coupled power output from the directional coupler, and then processes the detected output voltage to obtain the output power. However, there are several drawbacks: First, the high-power directional coupler causes power loss in the transmitter, leading to a reduction in the transmitter's output power. Second, because the directional coupler needs to operate under high power conditions for extended periods, this leads to continuous degradation of its internal performance, specifically increased signal distortion and reduced overall reliability. Third, directional couplers and RF detectors are expensive and bulky.

[0024] To solve the above problems, such as Figure 1 As shown, this application provides an output power detection circuit for a transmitter. The transmitter includes a power amplifier 110, and the detection circuit includes: The sampling module 120 is used to sample the voltage between the power supply terminal and the power input terminal of the power amplifier 110 to obtain the sampled voltage Vs; Amplification module 130, whose input terminal is connected to sampling module 120, amplifies the sampled voltage Vs to obtain amplified voltage Vc; The signal processing module 140, whose input is connected to the amplification module 130, performs analog-to-digital conversion and signal analysis on the amplified voltage Vc to obtain the output power Pout.

[0025] Specifically, such as Figure 1 As shown, power amplifier 110 is located on the signal transmission link of the transmitter. The input terminal of power amplifier 110 is connected to the radio frequency signal. Power amplifier 110 amplifies the radio frequency signal to obtain the output power. Typically, an isolator is also set after power amplifier 110 to ensure that the output power can be transmitted normally to the antenna for wireless signal transmission. The output power detection circuit of power amplifier 110 includes sampling module 120, amplification module 130, and signal processing module 140. Sampling module 120 is located between the power supply terminal and the power input terminal of power amplifier 110, and samples the voltage drop between the power supply terminal and the power input terminal to obtain the sampling voltage Vs. The input terminal of amplification module 130 is connected to the output terminal of sampling module 120. Amplification module 130 amplifies the sampling voltage Vs to obtain the amplified voltage Vc. The input terminal of signal processing module 140 is connected to the output terminal of amplification module 130. Signal processing module 140 performs analog-to-digital conversion and signal analysis on the amplified voltage Vc to obtain the output power Pout.

[0026] In detail, the sampling module 120 includes a sampling resistor Rc, with its first end connected to the power supply terminal and its second end connected to the power input terminal of the power amplifier 110. Specifically, as shown... Figure 2 As shown, the sampling module 120 includes a sampling resistor Rc. The first end of the sampling resistor Rc is connected to the power supply terminal, which provides the power supply voltage. The second end of the sampling resistor Rc is connected to the power input terminal of the power amplifier 110. The sampling resistor Rc can be a single resistor or a combination of two or more resistors connected in series and / or in parallel. This is not limited here.

[0027] More specifically, to improve the accuracy of output power calculation, the resistance value of the sampling resistor Rc is in the milliohm range, for example: the resistance value of the sampling resistor Rc is 20 milliohms.

[0028] In detail, such as Figure 3 As shown, the amplification module 130 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a first operational amplifier COMP1, a second operational amplifier COMP2, and a third operational amplifier COMP3. The inverting input terminal of the first operational amplifier COMP1 is connected to its output terminal via the first resistor R1. The output terminal of the first operational amplifier COMP1 is connected to the inverting input terminal of the second operational amplifier COMP2 via the second resistor R2. The inverting input terminal of the second operational amplifier COMP2 is also connected to its output terminal via the third resistor R3. The inverting input terminal of the third operational amplifier COMP3 is connected to its output terminal via the fourth resistor R4. The output terminal of the third operational amplifier COMP3 is connected to its output terminal via the fifth resistor R7. Resistor R5 is connected to the non-inverting input of the second operational amplifier COMP2. The non-inverting input of the second operational amplifier COMP2 is grounded after passing through the sixth resistor R6. The first end of the seventh resistor R7 is connected to the inverting input of the first operational amplifier COMP1, and the second end of the seventh resistor R7 is connected to the inverting input of the third operational amplifier COMP3. The non-inverting input of the third operational amplifier COMP3 is connected to the first end of the sampling resistor Rc, and the non-inverting input of the first operational amplifier COMP1 is connected to the second end of the sampling resistor Rc. The non-inverting inputs of the first operational amplifier COMP1 and the third operational amplifier COMP3 are the inputs of the amplification module 130. The input of the amplification module 130 is the sampling voltage Vs. The output of the second operational amplifier COMP2 is the output of the amplification module 130, and the output of the amplification module 130 is the amplified voltage Vc.

[0029] More specifically, the resistance of the first resistor R1 is equal to the resistance of the fourth resistor R4, the resistance of the second resistor R2 is equal to the resistance of the fifth resistor R5, and the resistance of the third resistor R3 is equal to the resistance of the sixth resistor R6.

[0030] In detail, the signal processing module 140 includes an analog-to-digital converter (ADC) unit and an analysis unit. The input of the ADC unit is connected to the amplification module 130, which samples the amplified voltage Vc and performs analog-to-digital conversion on the amplified voltage Vc to obtain a digital signal. The input of the analysis unit is connected to the ADC unit, which performs data mapping on the digital signal based on a preset calibration mapping relationship to obtain the output power Pout. Specifically, the ADC unit converts the amplified voltage Vc into a hexadecimal digital signal. The analysis unit performs data mapping on the received digital signal and the preset calibration mapping relationship to obtain the output power Pout of the power amplifier 110, thereby realizing the detection of the transmitter's output power. The ADC unit uses the built-in ADC structure of a Field-Programmable Gate Array (FPGA), which can achieve an effective resolution of 0.0012V.

[0031] Please refer to Figures 1 to 3 As shown, the working principle of the transmitter output power detection circuit provided in this application is as follows: like Figure 1-2 As shown, the voltage drop between the power supply terminal and the power supply terminal of the power amplifier 110 is sampled by the sampling resistor Rc in the sampling module 120 to obtain the sampling voltage Vs; the sampling voltage Vs is amplified by the amplification module 130 to obtain the amplified voltage Vc; the amplified voltage Vc is converted into a digital signal by the signal processing module 140, and the data signal is analyzed and processed to obtain the output power Pout of the transmitter.

[0032] Due to the power efficiency of power amplifier 110 ( Power efficiency is characterized as the ratio of the output power of a power amplifier to the total power supplied by the power supply voltage. The definite expression for ) is shown in (1): ) (1) in, For power efficiency, For output power, This is the power supply voltage for the power amplifier. This is the power supply current for the power amplifier.

[0033] Transform expression (1) to obtain expression (2): (2) in, For power efficiency, For output power, This is the power supply voltage for the power amplifier. This is the power supply current for the power amplifier.

[0034] Supply current The definite expression is shown in (3): (3) Among them, I DD Vs is the power supply current of the power amplifier, and Vs is the sampling voltage across the sampling resistor Rc. This is the sampling resistor.

[0035] Combining expressions (2) and (3), the expression for determining the output power Pout is shown in (4): (4) in, For power efficiency, For output power, This is the power supply voltage for the power amplifier. The sampling voltage across the sampling resistor Rc is This is the sampling resistor.

[0036] In the detection circuit, power efficiency ( The resistance value of the sampling resistor Rc and the supply voltage V DD Given the parameters, according to expression (4), it can be seen that only the voltage drop across the sampling resistor Rc needs to be sampled to obtain the sampling voltage Vs, and the output power Pout of the power amplifier 110 can be calculated based on the sampling voltage Vs.

[0037] In the amplification module 130, the amplification module 130 amplifies the input sampling voltage Vs to obtain the amplified voltage Vc. Since the resistance values ​​of the first resistor R1 and the fourth resistor R4 are equal, the resistance values ​​of the second resistor R2 and the fifth resistor R5 are equal, and the resistance values ​​of the third resistor R3 and the sixth resistor R6 are equal, the expression for determining the amplified voltage Vc is shown in (5): (5) Where Vc is the amplified voltage, Vs is the sampling voltage, R1 is the first resistor, R2 is the second resistor, R3 is the third resistor, and R7 is the seventh resistor.

[0038] The sampling module 120 outputs a sampling voltage Vs, and the amplification module 130 has a gain of 100, amplifying the sampling voltage Vs by 100 times to obtain an amplified voltage Vc. The amplified voltage Vc is then sampled by the analog-to-digital conversion unit, and the sampled amplified voltage Vc is converted from analog to digital to obtain a hexadecimal digital signal. The digital signal is then sent to the analysis unit, which performs data mapping on the digital signal based on a preset calibration mapping relationship to detect the output power of the power amplifier 110 and obtain the output power Pout.

[0039] The detection circuit provided in this application operates at a frequency of 2.0 GHz; the power detection range of the detection circuit is 23 to 38 dBm; the power detection accuracy of the detection circuit is ±0.5 dB; and the maximum output power of the power amplifier 110 is 38 dBm (continuous wave).

[0040] This application also provides a method for detecting the output power of a transmitter, the method being applied to the output power detection circuit of the transmitter as described above, the method comprising: Obtain the sampled voltage Vs; The sampled voltage Vs is amplified, and the amplified voltage is subjected to analog-to-digital conversion and signal analysis to obtain the output power Pout.

[0041] Specifically, the sampling voltage Vs is output based on the sampling resistor Rc in the sampling module 120. The sampling voltage Vs is amplified by the amplification module 130 to obtain the amplified voltage Vc. The amplified voltage Vc is then converted from analog to digital and processed by the signal processing module 140 to obtain the output power Pout.

[0042] Specifically, before acquiring the sampling voltage Vs, the method further includes: controlling the power detection circuit to be in a calibration state and acquiring multiple output powers and their corresponding sampling voltages; amplifying the multiple sampling voltages and converting them into multiple digital signals; establishing a calibration mapping relationship between the multiple digital signals and the multiple output powers, and storing the calibration mapping relationship in the signal processing module. Specifically, the power detection circuit 110 is controlled to be in a calibration state, acquiring multiple output powers output by the power amplifier 110 and their corresponding sampling voltages, amplifying and converting the multiple sampling voltages to hexadecimal to obtain multiple digital signals, establishing a calibration mapping relationship between the multiple digital signals and the multiple output powers, and storing the calibration mapping relationship in the signal processing module. For example, when the output power of the power amplifier 110 is 38dBm, the digital signal corresponding to the sampling voltage is a CFD. The mapping relationship between the output power 38dBm and the digital signal CFD is stored in the analysis unit of the signal processing module. When the digital signal is read as CFD again, the analysis unit can then report that the output power is 38dBm.

[0043] In detail, the sampled voltage Vs is amplified, and the amplified voltage is subjected to analog-to-digital conversion and signal analysis to obtain the output power Pout, including: amplifying the sampled voltage Vs to obtain the amplified voltage Vc; The amplified voltage Vc is converted from analog to digital to obtain a digital signal; the digital signal is then mapped based on a calibration mapping relationship to obtain the output power Pout. Specifically, the sampled voltage Vs is amplified by a preset factor through the amplification module 130 to obtain the amplified voltage Vc. The amplified voltage Vc is then converted from analog to digital by the analog-to-digital conversion unit to obtain a hexadecimal digital signal. The digital signal is then mapped based on a preset calibration mapping relationship to obtain the output power Pout corresponding to the digital signal.

[0044] When the supply voltage is 28V and the gain of the amplifier module 130 is 100, the sampled voltage Vs is amplified. Based on the detection principle of the detection circuit, the detection results are shown in Table 1: Table 1. Detection results of the detection circuit

[0045] As shown in Table 1, the error between the output power of the detection circuit and the actual output power is within ±0.2dB, which is highly accurate and meets the actual engineering requirements.

[0046] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A transmitter output power detection circuit, characterized in that, The transmitter includes a power amplifier, and the detection circuit includes: The sampling module is used to sample the voltage between the power supply terminal and the power input terminal of the power amplifier to obtain the sampled voltage; An amplification module, whose input is connected to the sampling module, amplifies the sampled voltage to obtain an amplified voltage; The signal processing module, whose input is connected to the amplification module, performs analog-to-digital conversion and signal analysis on the amplified voltage to obtain the output power.

2. The transmitter output power detection circuit according to claim 1, characterized in that, The sampling module includes a sampling resistor, with a first end connected to the power supply terminal and a second end connected to the power input terminal of the power amplifier.

3. The transmitter output power detection circuit according to claim 2, characterized in that, The resistance of the sampling resistor is in the milliohm range.

4. The transmitter output power detection circuit according to claim 1, characterized in that, The amplification module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first operational amplifier, a second operational amplifier, and a third operational amplifier. The inverting input terminal of the first operational amplifier is connected to its output terminal via the first resistor. The output terminal of the first operational amplifier is connected to its inverting input terminal via the second resistor. The inverting input terminal of the second operational amplifier is also connected to its output terminal via the third resistor. The inverting input terminal of the third operational amplifier is connected to its output terminal via the fourth resistor. The output terminal of the third operational amplifier is connected to its non-inverting input terminal via the fifth resistor. The non-inverting input terminal of the second operational amplifier is grounded via the sixth resistor. The first terminal of the seventh resistor is connected to the inverting input terminal of the first operational amplifier, and the second terminal of the seventh resistor is connected to the inverting input terminal of the third operational amplifier. The non-inverting input terminals of the first and third operational amplifiers are the input terminals of the amplification module, and the output terminal of the second operational amplifier is the output terminal of the amplification module.

5. The transmitter output power detection circuit according to claim 4, characterized in that, The resistance values ​​of the first resistor and the fourth resistor are equal, the resistance values ​​of the second resistor and the fifth resistor are equal, and the resistance values ​​of the third resistor and the sixth resistor are equal.

6. The transmitter output power detection circuit according to claim 1, characterized in that, The signal processing module includes an analog-to-digital conversion unit and an analysis unit. The input terminal of the analog-to-digital conversion unit is connected to the amplification module, which samples the amplified voltage and performs analog-to-digital conversion on the amplified voltage to obtain a digital signal. The input terminal of the analysis unit is connected to the analog-to-digital conversion unit, which performs data mapping on the digital signal based on a preset calibration mapping relationship to obtain the output power.

7. A method for detecting the output power of a transmitter, characterized in that, The method is applied to the output power detection circuit of the transmitter as described in any one of claims 1-6, comprising: Obtain the sampled voltage; The sampled voltage is amplified, and the amplified voltage is subjected to analog-to-digital conversion and signal analysis to obtain the output power.

8. The transmitter output power detection method according to claim 7, characterized in that, Before acquiring the sampled voltage, the method further includes: The control power detection circuit is in a calibration state and acquires multiple output powers and their corresponding sampling voltages; The multiple sampled voltages are amplified and converted into multiple digital signals; Establish calibration mapping relationships between multiple digital signals and multiple output powers, and store the calibration mapping relationships in the signal processing module.

9. The transmitter output power detection method according to claim 8, characterized in that, The sampled voltage is amplified, and the amplified voltage is subjected to analog-to-digital conversion and signal analysis to obtain the output power, including: The sampled voltage is amplified to obtain an amplified voltage; The amplified voltage is converted from analog to digital to obtain a digital signal; The digital signal is mapped based on the calibration mapping relationship to obtain the output power.

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