Temperature compensation circuit and method for a power detector

Abstract

The application discloses a temperature compensation circuit and method of a power detector, comprising a VDET voltage generating circuit, six reference voltage generating circuits, six IACL modules, a first triode, a second triode, a third triode, an eighth resistor, a ninth resistor, a fourth triode, an output current of the power detector, a reference current, a first bandgap current source, a PTAT current source, a second bandgap current source, a third bandgap current source, six control signals SEL and six control signals SELN; by comparing the VDET voltage and the reference voltage, a compensation current is dynamically adjusted; meanwhile, by adjusting the proportional relationship between the first bandgap current source and the PTAT current source, different compensation currents are provided at different temperatures.

Description

Technical Field

[0001] This invention belongs to the field of electronic circuit design technology, specifically relating to a temperature compensation circuit and method for a power detector. Background Technology

[0002] Power detectors are primarily used to measure power in circuits or signals. Specifically, they extract the power information of an input signal and output it as voltage or current. They are widely used in wireless communication, radio frequency engineering, microwave engineering, optical communication, and other fields. For example, in communication systems, they are used to measure transmit and receive power to ensure signal quality and network performance. They are also used in antenna systems, radar systems, and radio frequency amplifiers to control and monitor power levels. The design and performance characteristics of a power detector depend on the specific application requirements and frequency range.

[0003] Temperature compensation is an important design consideration in power detectors. The performance of many electronic components and materials changes with temperature. Therefore, the main purpose of temperature compensation is to ensure that the power values ​​detected at different temperatures have stable accuracy and reliability.

[0004] Here are some important implications of temperature compensation in power detectors: (1) Accuracy and stability: Temperature changes can affect the characteristics of electronic components, such as resistance, capacitance and amplification factor. If the power detector is not designed to take temperature compensation into account, the power values ​​measured at different temperatures may deviate, thereby reducing the accuracy and stability of the measurement.

[0005] (2) Error elimination: Temperature compensation in power detectors can help eliminate temperature-induced errors. By employing appropriate compensation techniques, power can be corrected at different temperatures to ensure that the output power value remains consistent under various environmental conditions.

[0006] (3) Stability and reliability: Temperature changes may cause the performance of electronic components to become unstable, or even cause component failure. By using temperature compensation technology, the impact of temperature changes on the performance of power detectors can be mitigated, thereby improving the stability and reliability of the equipment.

[0007] (4) Extended operating temperature range: Some application environments may face extreme temperature conditions, such as high or low temperature environments. Temperature compensation can help the power detector operate normally under these extreme conditions and ensure performance.

[0008] (5) Compliance with specified standards: Many industries and applications have strict requirements for the accuracy and stability of power measurement, especially in wireless communication, radar and other fields. Temperature compensation can help power detectors meet these specified standards.

[0009] In summary, temperature compensation plays a crucial role in power detectors, ensuring reliable and accurate power measurement results under different temperature conditions, thus improving the performance and reliability of the equipment.

[0010] In integrated circuit power detectors, the choice of temperature compensation methods differs slightly from that in external power detectors because the size and complexity of the integrated circuits typically limit the available options. Below are some common temperature compensation methods used in integrated circuit power detectors and their potential drawbacks: (1) Integrated temperature sensor. Its advantages are: the built-in temperature sensor can monitor the chip temperature in real time and can provide high precision and accuracy. However, its disadvantages are: the integrated sensor may increase the complexity and cost of the power detector, and the performance of the integrated sensor may be affected by the temperature sensitivity of the electronic components.

[0011] (2) Digital temperature compensation algorithm. Its advantages are: it uses digital signal processing technology to monitor temperature changes and apply correction algorithms, which is highly flexible and can be adapted to different power detectors. However, its disadvantages are: it requires additional computing resources, which may increase the power detection delay, and the performance of the algorithm depends on the quality and accuracy of the input data.

[0012] (3) Temperature compensation circuit. Its advantages are: it can be integrated into the power detector without the need for an additional sensor, and it can adjust the power measurement in real time to provide accuracy. However, its disadvantages are: it requires additional circuitry, which increases the complexity and cost of the power detector, and the performance of the temperature compensation circuit may be affected by the drift of electronic components.

[0013] (4) Calibration coefficient table, its advantages are: it can provide accurate calibration factors at different temperatures and can reduce the complexity of the power detector. However, its disadvantages are: it requires calibration at different temperatures, which may consume time and resources, and the accuracy depends on the quality and accuracy of the calibration coefficient table.

[0014] In on-chip power detectors, temperature compensation is typically achieved through an integrated circuit to minimize the need for external components. Different applications and design requirements may necessitate different choices of temperature compensation methods, requiring trade-offs between performance, cost, and complexity.

[0015] In power detector circuits, temperature compensation is often implemented using on-chip temperature compensation circuits to minimize cost and complexity. However, traditional temperature compensation circuits have some significant problems: (1) Traditional temperature compensation circuits only compensate for temperature and do not consider the actual input signal power, resulting in a single compensation method and limited compensation effect; (2) Traditional temperature compensation circuits have poor compensation accuracy at high and low temperatures, and the circuit itself is easily affected by temperature, which further deteriorates the compensation accuracy. Summary of the Invention

[0016] Purpose of the invention: To address the problems existing in current temperature compensation circuits, this invention proposes a temperature compensation circuit for a power detector.

[0017] Technical solution: A temperature compensation circuit for a power detector, comprising: a VDET voltage generation circuit, six reference voltage generation circuits, six IACL modules, a first transistor, a second transistor, a third transistor, an eighth resistor, a ninth resistor, a fourth transistor, the output current of the power detector, a reference current, a first bandgap current source, a PTAT current source, a second bandgap current source, a third bandgap current source, six control signals SEL and six control signals SELN; The VDET voltage generation circuit is used to output VDET voltage based on the output current of the power detector; The six reference voltage generation circuits are used to output six sets of reference voltages based on the reference current; Each of the IACL modules includes: a first field-effect transistor, a second field-effect transistor, a third field-effect transistor, and a fourth field-effect transistor; The source of the first field-effect transistor, the source of the second field-effect transistor, and the drain of the third field-effect transistor are connected together. The drain of the first field-effect transistor is connected to the power supply, the gate of the first field-effect transistor is connected to the VDET voltage, and the drain of the fourth field-effect transistor is connected to the power supply. The gate of the second field-effect transistor is connected to the corresponding reference voltage; The gate of the third field-effect transistor is used to connect to the corresponding control signal SEL, and the source of the third field-effect transistor is connected to the upper end of the third bandgap current source. The gate of the fourth field-effect transistor is used to connect to the corresponding control signal SELN, and the source of the fourth field-effect transistor is connected to the upper end of the third bandgap current source; the lower end of the third bandgap current source is grounded. The drains of the second field-effect transistors in the six IACL modules are all connected together and connected to the emitters of the first transistor, the second transistor, and the third transistor; the collectors of the first transistor, the third transistor, and the second transistor form the output port of the temperature compensation circuit. One end of the first bandgap current source is connected to a power supply, and the other end is connected to one end of the PTAT current source. The other end of the PTAT current source is grounded, and the base of the first transistor is connected to the other end of the first bandgap current source. One end of the eighth resistor is connected to the other end of the first bandgap current source. The other end of the eighth resistor is connected to one end of the ninth resistor. The other end of the ninth resistor is connected to the emitter of the fourth transistor. The base of the second transistor is connected to the other end of the eighth resistor. The base of the third transistor is connected to the emitter of the fourth transistor. The emitter of the fourth transistor is grounded through the second bandgap current source. The base and collector of the fourth transistor are connected and are both connected to a power supply.

[0018] Furthermore, the VDET voltage generating circuit includes a first resistor, one end of which is connected to a power supply, and the other end is connected to the output current of a power detector. The VDET voltage is obtained by drawing out the other end of the first resistor.

[0019] Furthermore, the six reference voltage generating circuits include a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor, which are connected in series to form a resistor string. A reference current is connected to the second resistor, and a first reference voltage is obtained from the connection point between the reference current and the second resistor, a second reference voltage is obtained from the connection point between the second and third resistors, a third reference voltage is obtained from the connection point between the third and fourth resistors, a fourth reference voltage is obtained from the connection point between the fourth and fifth resistors, a fifth reference voltage is obtained from the connection point between the fifth and sixth resistors, and a sixth reference voltage is obtained from the connection point between the sixth and seventh resistors.

[0020] Furthermore, the control signal SELN is inverted to obtain the control signal SEL.

[0021] This invention discloses a temperature compensation method for a power detector, comprising the following steps: Build a temperature compensation circuit; Adjust the ratio between the first bandgap current source and the PTAT current source; The output current, reference current, six control signals SEL, and six control signals SELN of the power detector are input to the temperature compensation circuit, which outputs the temperature compensation current.

[0022] Beneficial effects: Compared with the prior art, the present invention has the following advantages: (1) The temperature compensation circuit proposed in this invention dynamically adjusts the compensation current by comparing the VDET voltage and the reference voltage; (2) The temperature compensation circuit proposed in this invention achieves different compensation currents at different temperatures by adjusting the ratio of the bandgap current source and the PTAT current source. Attached Figure Description

[0023] Figure 1 This is a temperature compensation circuit diagram for a power detector. Figure 2 A schematic diagram illustrating how to dynamically adjust the compensation current by comparing the VDET voltage with the reference voltage; Figure 3 A schematic diagram illustrating how to adjust the ratio between the first bandgap current source and the PTAT current source to provide different compensation currents at different temperatures; Figure 4 This is a schematic diagram showing the discrete phenomenon of detector output voltage at high and low temperatures when the input power is low; Figure 5 This diagram illustrates a temperature compensation circuit for a power detector proposed in this embodiment. A fixed current is supplied to the power detector, and the ratio of the first bandgap current source and the PTAT current source can be adjusted by different codewords to compensate the output current of the power detector and ensure the consistency of the detector's output voltage under high and low temperatures. Detailed Implementation

[0024] The technical solution of the present invention will now be further described in conjunction with the accompanying drawings and embodiments.

[0025] like Figure 1 As shown, this embodiment proposes a temperature compensation circuit for a power detector, which mainly 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, six IACL modules, a first transistor B1, a second transistor B2, a third transistor B3, an eighth resistor R8, a ninth resistor R9, a fourth transistor B4, an output current I1 of the power detector, a reference current I2, a first bandgap current source I3, a PTAT current source I4, a second bandgap current source I5, a bandgap current source I6, control signals SEL<5:0> and SELN<5:0>. The second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7 are connected in series to form a resistor string. The IACL module in this embodiment includes a first field-effect transistor M1, a second field-effect transistor M2, a third field-effect transistor M3, and a fourth field-effect transistor M4. The source of the first field-effect transistor M1, the source of the second field-effect transistor M2, and the drain of the third field-effect transistor M3 are connected together, and the source of the third field-effect transistor M3 and the source of the fourth field-effect transistor M4 are connected together.

[0026] like Figure 1As shown, the output current I1 of the power detector generates the voltage VDET through the first resistor R1, and the reference current I2 generates the reference voltage VREF through the resistor series. <0> ~VREF <5> The VDET voltage is connected to the gate of the first field-effect transistor M1 in the six IACL modules (i.e., ICAL<5:0>), with a reference voltage VREF. <5> ~VREF <0> The drains of each of the six IACL modules are connected to the gates of the corresponding second field-effect transistors M2. The drains of all the second field-effect transistors M2 in the six IACL modules are connected together, and then connected to the emitters of the first transistor B1, the second transistor B2, and the third transistor B3. The gates of the corresponding third field-effect transistors M3 in the six IACL modules are connected to the corresponding control signals SEL<5:0> and SELN<5:0>. The gates of the fourth field-effect transistor M4 are connected to the corresponding control signals SELN<5:0>. The control signals SEL<5:0> and SELN<5:0> are controlled by the same control signal Fine_tune<5:0>. Fine_tune<5:0> originates from the digital module, is converted to control signal SELN<5:0> by inverter INV1, and then converted to control signal SEL<5:0> by inverter INV2. This control signal primarily serves to finely control the output current of the six IACL modules. In the six ICAL modules, the source terminals of the third field-effect transistor M3 and the fourth field-effect transistor M4 are all connected to the bandgap current source I6.

[0027] When the input power of the power detector is very small, the VDET voltage is also small, and both are lower than the reference voltage VREF. <0> ~VREF <5> Therefore, in each ICAL module, the second field-effect transistor M2 is turned on, and the first field-effect transistor M1 is turned off. All current flows through the second field-effect transistor M2 to the first transistor B1, the second transistor B2, and the third transistor B3. As the input power gradually increases, the VDET voltage also increases, thus becoming more similar to the reference voltage VREF. <0> ~VREF <5> During the comparison, the second field-effect transistor M2 in the ICAL module is gradually turned off, causing the current flowing to the first transistor B1, the second transistor B2, and the third transistor B3 to decrease. Therefore, as the input power increases, the compensation current will decrease. This process can be referenced. Figure 2 .

[0028] The first bandgap current source I3 and the PTAT current source I4 are connected together and connected to one end of the eighth resistor R8. One end of the ninth resistor R9 is connected to the other end of the eighth resistor R8, and the other end of the ninth resistor R9 is connected to the second bandgap current source I5. The upper end of the second bandgap current source I5 is connected to the emitter of the fourth transistor B4. The base of the fourth transistor B4 is connected to the collector of the fourth transistor B4. The collector of the fourth transistor B4 is connected to the power supply. At this time, the emitter voltage of the fourth transistor B4 is the power supply voltage minus Vbe. This emitter node is a low-resistance node. When the temperature changes, the current generated by the PTAT current source I4 changes, while the current of the first bandgap current source I3 remains constant. This results in a difference between the currents from the two current sources. The excess current flows through the eighth resistor R8 and the ninth resistor R9 to the second bandgap current source I5, creating a voltage difference across them. The larger the voltage difference, the larger the current at the output terminal IOUTP and the smaller the current at IOUTN. By adjusting the ratio of the first bandgap current source I3 to the PTAT current source I4, different current magnitudes can be compensated at high and low temperatures. This process can be referenced. Figure 2 .

[0029] The temperature compensation circuit of the power detector proposed in this embodiment dynamically adjusts the compensation current by comparing the VDET voltage with the reference voltage. At the same time, by adjusting the ratio of the first bandgap current source I3 and the PTAT current source I4, different compensation currents are provided at different temperatures.

[0030] like Figure 4 As shown, the detector output voltage exhibits dispersion at low input power and low temperatures. At this lower input power range, the output voltage is smaller (i.e., the output current is smaller) at high temperatures (120℃), and larger (i.e., the output current is larger) at low temperatures (-40℃). In this case, the temperature compensation circuit disclosed in this embodiment provides a fixed current to the power detector. The ratio of the first bandgap current source I3 and the PTAT current source I4 can be adjusted using different codewords. When the given codeword makes the ratio of the first bandgap current source I3 and the PTAT current source I4 close at low temperatures, the current of the PTAT current source I4 increases at room temperature. The excess current flows from R9 to R8, generating a negative voltage difference. At high temperatures, the current of the PTAT current source I4 further increases, resulting in a larger voltage difference. The larger the voltage difference, the more current IOUTP outputs. Therefore, this current passes through… Figure 3 It can achieve a significant increase at high temperatures, a constant increase at low temperatures, and a small increase at room temperature, thereby compensating for the output current of the power detector and ensuring the consistency of the detector's output voltage under high and low temperatures. Figure 5 As shown. Furthermore, by modifying this codeword, the compensation current can be varied at different temperatures to handle more complex temperature compensation scenarios.

Claims

1. A temperature compensation circuit for a power detector, characterized in that: include: VDET voltage generation circuit, 6 reference voltage generation circuits, 6 IACL modules, first transistor, second transistor, third transistor, eighth resistor, ninth resistor, fourth transistor, output current of power detector, reference current, first bandgap current source, PTAT current source, second bandgap current source, third bandgap current source, 6 control signals SEL and 6 control signals SELN; The VDET voltage generation circuit is used to output VDET voltage based on the output current of the power detector; The six reference voltage generation circuits are used to output six sets of reference voltages based on the reference current; Each of the IACL modules includes: a first field-effect transistor, a second field-effect transistor, a third field-effect transistor, and a fourth field-effect transistor; The source of the first field-effect transistor, the source of the second field-effect transistor, and the drain of the third field-effect transistor are connected together. The drain of the first field-effect transistor is connected to the power supply, the gate of the first field-effect transistor is connected to the VDET voltage, and the drain of the fourth field-effect transistor is connected to the power supply. The gate of the second field-effect transistor is connected to the corresponding reference voltage; The gate of the third field-effect transistor is used to connect to the corresponding control signal SEL, and the source of the third field-effect transistor is connected to the upper end of the third bandgap current source. The gate of the fourth field-effect transistor is used to connect to the corresponding control signal SELN, and the source of the fourth field-effect transistor is connected to the upper end of the third bandgap current source; the lower end of the third bandgap current source is grounded. The drains of the second field-effect transistors in the six IACL modules are all connected together and connected to the emitters of the first transistor, the second transistor, and the third transistor; the collectors of the first transistor, the third transistor, and the second transistor form the output port of the temperature compensation circuit. One end of the first bandgap current source is connected to a power supply, and the other end is connected to one end of the PTAT current source. The other end of the PTAT current source is grounded, and the base of the first transistor is connected to the other end of the first bandgap current source. One end of the eighth resistor is connected to the other end of the first bandgap current source. The other end of the eighth resistor is connected to one end of the ninth resistor. The other end of the ninth resistor is connected to the emitter of the fourth transistor. The base of the second transistor is connected to the other end of the eighth resistor. The base of the third transistor is connected to the emitter of the fourth transistor. The emitter of the fourth transistor is grounded through the second bandgap current source. The base and collector of the fourth transistor are connected and are both connected to a power supply.

2. The temperature compensation circuit for a power detector according to claim 1, characterized in that: The VDET voltage generating circuit includes a first resistor, one end of which is connected to a power supply, and the other end is connected to the output current of a power detector. The VDET voltage is obtained by drawing out the other end of the first resistor.

3. The temperature compensation circuit for a power detector according to claim 1, characterized in that: The six reference voltage generating circuits include a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor, which are connected in series to form a resistor string. A reference current is connected to the second resistor. A first reference voltage is obtained from the connection point between the reference current and the second resistor. A second reference voltage is obtained from the connection point between the second and third resistors. A third reference voltage is obtained from the connection point between the third and fourth resistors. A fourth reference voltage is obtained from the connection point between the fourth and fifth resistors. A fifth reference voltage is obtained from the connection point between the fifth and sixth resistors. A sixth reference voltage is obtained from the connection point between the sixth and seventh resistors.

4. The temperature compensation circuit for a power detector according to claim 1, characterized in that: The control signal SELN is converted into the control signal SEL by an inverter.

5. A temperature compensation method for a power detector, characterized in that: Includes the following steps: Build a temperature compensation circuit; Adjust the ratio between the first bandgap current source and the PTAT current source; The output current, reference current, six control signals SEL and six control signals SELN of the power detector are input to the temperature compensation circuit, which outputs the temperature compensation current. The temperature compensation circuit is a temperature compensation circuit for a power detector as described in any one of claims 1 to 4.

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