Transmitter and gain temperature compensation circuit thereof

Abstract

The invention provides a transmitter and a gain temperature compensation circuit thereof, and the output end of a temperature detection circuit is connected with the control end of a variable resistance circuit. The variable resistance circuit is connected in parallel with the input end of a power amplifier in the transmitter; the temperature detection circuit outputs a control signal to the variable resistance circuit according to the detected temperature and adjusts the resistance value of the variable resistance circuit; by introducing the variable resistance circuit and the temperature detection circuit and dynamically adjusting the resistance value according to the temperature change, the adjustment of the load in the transmitter can be effectively realized, so that the gain is kept relatively constant under different temperature conditions, and the design not only improves the stability and reliability of the circuit, but also improves the reliability of the circuit. And the performance of the circuit under different environmental conditions is optimized, the power consumption of the transmitter is reduced, the working point of a transistor in the transmitter is not influenced, and the performance of the transmitter is relatively stable.

Description

Technical Field

[0001] The present invention belongs to the technical field of transmitters, and more specifically, relates to a transmitter and a gain temperature compensation circuit thereof. Background Art

[0002] Wireless communication systems play a vital role in modern society. Their performance and stability directly affect the quality of communication services and user experience. As the core component of wireless communication systems, transmitters (TX) are responsible for converting digital baseband signals into RF signals and transmitting them efficiently. The design of the transmitter must not only ensure that the signal distortion is as small as possible, but also maintain stable output power in various environments to meet the requirements of the communication protocol.

[0003] The current mainstream transmitter architecture generally adopts direct up-conversion technology, which includes key components such as DAC (Digital-to-Analog Converter), LPF (Low-Pass Filter), MXR (Mixer), DA (Driver Amplifier) ​​and PA (Power Amplifier). Among them, the output power of the transmitter is one of the important indicators to measure its performance. Different communication protocols have strict regulations on the output power of the transmitter. For example, the maximum transmission power of the GSM transmitter is 33dBm, while the maximum transmission power of the Wi-Fi transmitter is 21dBm.

[0004] Transmitters face many challenges in practical applications, especially the performance stability problem in different temperature environments. The operating temperature range of industrial-grade chips is usually between -40℃ and 85℃, which requires the transmitter to maintain stable output power in both low temperature (-40℃) and high temperature (85℃) environments. However, since the transconductance (gm) of CMOS process transistors changes with temperature, the gain of the transmitter will also fluctuate accordingly, which in turn affects the stability of the output power.

[0005] In order to solve the problem of transmitter output power changing with temperature, there are currently two main temperature compensation technology solutions: open-loop and closed-loop. The open-loop solution compensates by adjusting the current of the DA or PA, that is, adding a current source proportional to the absolute temperature inside the chip to compensate for the change in transistor transconductance with the current change caused by temperature change, thereby stabilizing the output power.

[0006] However, there are some problems with the open-loop solution: first, increasing the current will cause the chip temperature to rise, forming a positive feedback effect and increasing power consumption; second, the change in current will change the DC operating point of the transistor, thereby causing changes in circuit performance. Summary of the invention

[0007] In view of this, the object of the present invention is to provide a transmitter and a gain temperature compensation circuit thereof, which can effectively realize the adjustment of the load in the transmitter by introducing a variable resistor circuit and a temperature detection circuit and dynamically adjusting the resistance value according to the change of temperature, thereby keeping the gain relatively constant under different temperature conditions.

[0008] The first aspect of the present application discloses a gain temperature compensation circuit of a transmitter, comprising: a variable resistance circuit and a temperature detection circuit;

[0009] The output end of the temperature detection circuit is connected to the control end of the variable resistance circuit;

[0010] The variable resistance circuit is connected in parallel with the input end of the power amplifier in the transmitter;

[0011] The temperature detection circuit outputs a control signal to the variable resistance circuit according to the detected temperature to adjust the resistance value of the variable resistance circuit.

[0012] Optionally, the variable resistance circuit includes: N resistance units; N is a positive integer;

[0013] The control end of each of the resistance units serves as the control end of the variable resistance circuit;

[0014] Both ends of each of the resistor units are connected to the positive and negative input terminals of the power amplifier;

[0015] The temperature detection circuit controls the working state of each resistance unit according to the detected temperature.

[0016] Optionally, the resistance unit includes: a first resistor, a second resistor and a switch tube;

[0017] One end of the first resistor serves as one end of the resistor unit;

[0018] The other end of the first resistor is connected to one end of the switch tube;

[0019] The other end of the switch tube is connected to one end of the second resistor;

[0020] The other end of the second resistor serves as the other end of the resistor unit;

[0021] The control end of the switch tube serves as the control end of the resistance unit.

[0022] Optionally, a temperature detection circuit includes: a temperature sensor, an analog-to-digital converter and a mapping circuit;

[0023] The output end of the temperature sensor is connected to the input end of the analog-to-digital converter;

[0024] The output end of the analog-to-digital converter is connected to the input end of the mapping circuit;

[0025] The output end of the mapping circuit serves as the output end of the temperature detection circuit.

[0026] Optionally, the analog-to-digital converter is used to encode the temperature value of the temperature sensor to obtain a temperature digital signal;

[0027] The temperature values ​​belong to different ranges, and the corresponding temperature digital signals are different.

[0028] Optionally, the mapping circuit controls the working states of different resistance units according to different temperature digital signals.

[0029] Optionally, -40°C to 120°C is divided into 16 levels, wherein each 10°C is divided into one level; the temperature values ​​of the analog-to-digital converter belong to different levels, and the corresponding temperature digital signals are different.

[0030] Optionally, the temperature sensor is placed within a preset range of the power amplifier.

[0031] The second aspect of the present application discloses a transmitter, comprising: a gain compensation circuit, a radio frequency module, a driver amplifier, a power amplifier, a first transformer and a second transformer;

[0032] The positive and negative electrodes of the output terminal of the radio frequency module are connected to the positive and negative electrodes of the input terminal of the driving amplifier;

[0033] The positive and negative electrodes of the output terminal of the driving amplifier are connected to the two ends of the primary winding of the first transformer;

[0034] The two ends of the secondary winding of the first transformer are respectively connected to the two ends of the gain compensation circuit and the positive and negative electrodes of the input end of the power amplifier;

[0035] The positive and negative electrodes of the output terminal of the power amplifier are connected to the two ends of the primary winding of the second transformer;

[0036] One end of the secondary winding of the second transformer is grounded;

[0037] The other end of the secondary winding of the second transformer serves as the output end of the transmitter.

[0038] Optionally, the radio frequency module includes: a modem, a signal generator, a frequency divider, a 90° / 0 phase shifter, two digital-to-analog converters, two low-pass filter modules and two mixers;

[0039] The two digital-to-analog converters correspond to the two low-pass filter modules one by one; the two low-pass filter modules correspond to the two mixers one by one;

[0040] The modem outputs orthogonal I / Q digital signals to the two digital-to-analog converters respectively;

[0041] The output end of the digital-to-analog converter is connected to the input end of the corresponding low-pass filter;

[0042] The output end of the low-pass filter is connected to the first input end of the corresponding mixer;

[0043] The output end of the signal generator is connected to the input end of the frequency divider;

[0044] The output end of the frequency divider is connected to the input end of the 90° / 0 phase shifter;

[0045] The two output ends of the 90° / 0 phase shifter correspond to the two mixers one by one, and the two output ends of the 90° / 0 phase shifter are connected to the second input ends of the respective corresponding mixers;

[0046] The output end of the mixer serves as the output end of the radio frequency module.

[0047] It can be seen from the above technical scheme that the present invention provides a gain temperature compensation circuit of a transmitter, wherein the output end of the temperature detection circuit is connected to the control end of the variable resistor circuit; the variable resistor circuit is connected in parallel to the input end of the power amplifier in the transmitter; the temperature detection circuit outputs a control signal to the variable resistor circuit according to the detected temperature to adjust the resistance value of the variable resistor circuit; by introducing the variable resistor circuit and the temperature detection circuit, and dynamically adjusting its resistance value according to the change of temperature, the load adjustment in the transmitter can be effectively realized, thereby keeping the gain relatively constant under different temperature conditions. This design not only improves the stability and reliability of the circuit, but also optimizes the performance of the circuit under different environmental conditions, reduces the power consumption of the transmitter, and the operating point of the transistor in the transmitter is not affected, and the performance of the transmitter is relatively stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 is a schematic diagram of a transmitter and a gain temperature compensation circuit thereof provided by an embodiment of the present invention;

[0050] Figure 2 The present invention is a schematic diagram of a variable resistor circuit in a gain temperature compensation circuit of a transmitter provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] In the present application, the term "comprises", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "comprising one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements. In addition, the terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here, for example.

[0053] The embodiment of the present application provides a gain temperature compensation circuit for a transmitter, which is used to solve the problem in the prior art that increasing the current will cause the chip temperature to rise, forming a positive feedback effect, increasing power consumption, and the current change will change the DC operating point of the transistor, thereby causing changes in circuit performance.

[0054] See also Figure 1 , the transmitter gain temperature compensation circuit, including: variable resistor circuit R p_array and a temperature detection circuit 10.

[0055] The output terminal of the temperature detection circuit 10 is connected to the variable resistance circuit R p_array The control end connection.

[0056] That is, the output port of the temperature detection circuit 10 is connected to the variable resistance circuit R p_array This connection ensures that the temperature detection circuit 10 can transmit the detected temperature change information in the form of a control signal to the variable resistance circuit R in real time.p_array . Variable resistance circuit R p_array Connected in parallel with the input terminal of the power amplifier PA in the transmitter.

[0057] Specifically, the variable resistor circuit R p_array One end of the variable resistor circuit R is connected to the positive input terminal of the power amplifier PA. p_array The other end is connected to the negative input terminal of the power amplifier PA.

[0058] Variable resistor circuit R p_array The variable resistor circuit R p_array The input signal of the power amplifier PA can be directly modulated to adjust the gain of the entire transmitter.

[0059] The temperature detection circuit 10 outputs a control signal to the variable resistance circuit R according to the detected temperature. p_array , adjust the variable resistor circuit R p_array The resistance value is adjusted to achieve the temperature compensation function of the gain.

[0060] When the temperature detection circuit 10 detects a change in the ambient temperature, the temperature detection circuit 10 generates a corresponding control signal according to the ambient temperature. This control signal is then transmitted to the variable resistance circuit R p_array , to instruct it to adjust its own resistance value. By changing the resistance value, the variable resistor circuit R p_array It can affect the input impedance of the power amplifier PA and thus adjust the gain of the transmitter, thereby compensating for gain fluctuations that may be caused by temperature changes.

[0061] That is, the gain temperature compensation circuit of the transmitter detects the temperature change in real time through the temperature detection circuit 10 and controls the variable resistance circuit R p_array The resistor value can achieve precise adjustment of the transmitter gain, thus ensuring that the transmitter can maintain stable performance under various temperature conditions.

[0062] In addition, the temperature detection circuit 10 may have multiple output terminals connected to multiple input terminals of the variable resistor, so that each output terminal of the temperature detection circuit 10 can control the operation of the resistor corresponding to the input terminal connected to it. Of course, other methods may also be used, which will not be described here one by one.

[0063] Since the variable resistance circuit R p_array It is connected in parallel with the power amplifier PA, and then when the variable resistance circuit R p_array When the resistance value changes, the variable resistor circuit R p_arrayThe resistance of the parallel circuit with the power amplifier PA is adjusted by the variable resistance circuit R p_array The resistance value is used to adjust the input of the power amplifier PA.

[0064] It should be noted that the gain calculation formula It can be seen that the gain is determined by the transconductance gm and the load resistance value R LOAD The product determines that in order to maintain a constant gain, the change in transconductance can be compensated by changing the load at high and low temperatures.

[0065] This application introduces a variable resistance circuit R p_array , adjust the load resistance value at different temperatures to compensate for the changes in gm at high and low temperatures, so that the gain is relatively constant at high and low temperatures, and the change is less than 2dB.

[0066] Introducing the variable resistor circuit R p_array After that, the DA load is changed from the original R LOAD，DA Change to R LOAD，DA With R p_array Parallel, i.e. R p_array ||R LOAD，DA . Different R at high and low temperatures p_array The value affects the final R LOAD , i.e. g at low temperature m Too large, corresponding to small R LOAD ; High temperature g m Small, corresponding to large R LOAD , thus achieving relatively constant gain.

[0067] Introducing the variable resistor circuit R p_array After that, the DA load situation has changed. Originally, the DA load is only composed of a fixed resistor R LOAD，DA But now, R LOAD，DA With variable resistor circuit R p_array They are connected in parallel to form a new load for DA, that is, the equivalent load is R p_array With R LOAD，DA The parallel value (expressed as R p_array ||R LOAD，DA ).

[0068] This parallel structure uses the effect of temperature on the transconductance of the transistor. m The transconductance gm is an important parameter that describes the relationship between transistor current and voltage. It usually changes with temperature. In a low temperature environment, the transconductance gm of the transistor m This means that under the same input signal, the transistor can produce a larger output current. In order to keep the gain relatively constant, it is necessary to reduce the load resistance of the DA, that is, to choose a smaller R LOAD value (here, due to R p_arrayis variable, so in fact, by adjusting R p_array The value of R is indirectly realized LOAD，DA The equivalent load is reduced). Since R p_array With R LOAD，DA parallel connection, thus reducing R p_array This purpose can be achieved by using a resistance value of

[0069] On the contrary, in a high temperature environment, the transconductance g of the transistor m If the gain is too small, the output current capability will be weakened. In order to keep the gain relatively constant, it is necessary to increase the load resistance of the DA, that is, to select a larger R LOAD Similarly, by adjusting R p_array The resistance value (increase R p_array ), which can indirectly increase the equivalent load resistance of DA.

[0070] In this embodiment, by introducing a variable resistance circuit R p_array And the temperature detection circuit 10, and dynamically adjusts its resistance according to the change of temperature, can effectively realize the adjustment of the DA load in the transmitter, so as to keep the gain relatively constant under different temperature conditions. This design not only improves the stability and reliability of the circuit, but also optimizes the performance of the circuit under different environmental conditions, reduces the power consumption of the transmitter, and the operating point of the transistor in the transmitter is not affected, and the performance of the transmitter is relatively stable.

[0071] It is worth noting that the closed-loop solution monitors the power value of the antenna port in real time by introducing a power detection circuit, and feeds this value back to the digital baseband, and achieves output power stability by adjusting the gain (TPC) of each level of the transmitter circuit. However, this closed-loop solution also has some limitations: first, the design of the power detection circuit is relatively complex and is sensitive to changes in the antenna load, making it difficult to achieve accurate power detection; second, the circuit occupies a large chip area, increasing the cost of the chip.

[0072] In this embodiment, by introducing a variable resistance circuit R p_array And the temperature detection circuit 10, and dynamically adjusts its resistance according to the change of temperature, can effectively realize the adjustment of the DA load in the transmitter, so as to keep the gain relatively constant under different temperature conditions. The temperature detection circuit 10 is relatively simple and small in size, with high detection accuracy and reduced cost.

[0073] Optional, see Figure 2 , variable resistor circuit R p_array It includes: N resistance units 11; N is a positive integer.

[0074] N can be 16, or other values. p_array It can be a parallel resistor array.

[0075] The control end of each resistor unit 11 serves as a variable resistor circuit R p_array both ends of each resistor unit 11 are connected to the positive and negative input terminals of the power amplifier PA; the temperature detection circuit 10 controls the working state of each resistor unit 11 according to the detected temperature.

[0076] Each resistor unit 11 is equipped with a control terminal, and these control terminals together constitute a variable resistor circuit R p_array The main control interface of the circuit can realize flexible adjustment of the resistance value in the whole circuit by operating these control terminals.

[0077] When the control end of a certain resistor unit 11 receives a working signal, the resistor unit 11 starts to work, for example, it is put into the input end of the power amplifier PA, that is, the resistor unit 11 is connected in parallel with the input end of the power amplifier PA. According to the requirements, each resistor unit 11 can be controlled to be put into operation, a single resistor unit 11 can be controlled to be put into operation, or at least two resistor units 11 can be controlled to be put into operation. It will not be described here one by one, and it can be determined according to the actual situation, which is within the protection scope of this application.

[0078] In addition, both ends of each resistor unit 11 are connected to the positive and negative input terminals of the power amplifier PA. Specifically, one end of each resistor unit 11 is connected to the positive input terminal P of the power amplifier PA, and the other end of each resistor unit 11 is connected to the negative input terminal N of the power amplifier PA. Such a connection method ensures that the resistor unit 11 can effectively participate in the signal processing process of the power amplifier PA, thereby realizing accurate regulation of the signal strength.

[0079] In order to further improve the reliability and stability of the circuit, a temperature detection circuit 10 is also introduced. The circuit can detect the temperature change of the surrounding environment in real time, and intelligently control the working state of each resistance unit 11 accordingly. When the temperature is detected to be too high or too low, the temperature detection circuit 10 will take corresponding measures, such as adjusting the resistance value, to ensure that the circuit can operate under safe and stable conditions.

[0080] Optionally, the resistance unit 11 includes: a first resistor R1, a second resistor R2 and a switch tube Q.

[0081] One end of the first resistor R1 serves as one end of the resistor unit 11 and is connected to the positive input terminal P of the power amplifier PA.

[0082] The other end of the first resistor R1 is connected to one end of the switch tube Q; the other end of the switch tube Q is connected to one end of the second resistor R2.

[0083] The other end of the second resistor R2 serves as the other end of the resistor unit 11 and is connected to the negative input terminal N of the power amplifier PA.

[0084] The control end of the switch tube Q serves as the control end of the resistance unit 11 and receives the control signal of the temperature detection circuit 10 .

[0085] That is to say, the switch tube Q in each resistor unit 11 can independently receive the control signal of the temperature detection circuit 10, so that the temperature detection circuit 10 can independently control the on and off states of each switch tube Q, thereby realizing the control of the input and output of each resistor unit 11; for example, if the switch tube Q in a certain resistor unit 11 is in the on state under the control of the temperature detection circuit 10, then the resistor unit 11 is in the on state, and the resistor unit 11 is connected in parallel with the input end of the power amplifier PA. If the switch tube Q in a certain resistor unit 11 is in the off state under the control of the temperature detection circuit 10, then the resistor unit 11 is switched off, and the resistor unit 11 is in the open circuit state, and does not constitute a loop in the transmitter, that is, the resistor unit 11 has no effect on the transmitter.

[0086] In this embodiment, a variable load is realized by connecting a resistor array in parallel to the input end of the power amplifier PA, thereby reducing the influence on the working state of the core circuit power amplifier PA; the variable resistor circuit R p_array This is achieved by means of a parallel resistor array, which is relatively simple and does not increase the chip area.

[0087] Optionally, the temperature detection circuit 10 includes: a temperature sensor Temp-Sensor, an analog-to-digital converter GPADC and a mapping circuit Mapping Circuit.

[0088] The output end of the temperature sensor Temp-Sensor is connected to the input end of the analog-to-digital converter GPADC to ensure that the temperature signal captured by the sensor can be accurately transmitted to the analog-to-digital converter GPADC.

[0089] Optionally, the temperature sensor Temp-Sensor is placed within a preset range of the power amplifier PA. Specifically, the temperature sensor Temp-Sensor is placed close to the power amplifier PA to better convert the junction temperature (ambient temperature) of the chip near the power amplifier PA into the voltage signal VSENSE.

[0090] The output end of the analog-to-digital converter GPADC is connected to the input end of the mapping circuit.

[0091] After receiving the analog signal from the temperature sensor Temp-Sensor, the analog-to-digital converter GPADC converts it into a digital signal and transmits the digital signal to the mapping circuit through its output port. In other words, the voltage signal VSENSE reflecting the temperature information is converted into a digital signal.

[0092] The digital-to-analog converter may be a GPADC (General Purpose ADC), or other types, which will not be described in detail here.

[0093] The output end of the mapping circuit serves as the output end of the temperature detection circuit 10 .

[0094] The mapping circuit is responsible for further processing these digital signals, mapping them into codes corresponding to the actual temperature, and transmitting them to the variable resistance circuit R through its output port, that is, the output port of the entire temperature detection circuit 10. p_array Provide the final temperature detection information. That is, the mapping circuit selects a suitable mapping scheme to convert the digital signal into a control variable resistor circuit R p_array control word.

[0095] Such a circuit design makes the temperature detection process both accurate and efficient, and can meet the needs of temperature monitoring in various application scenarios.

[0096] Optionally, the analog-to-digital converter GPADC is used to encode the temperature value of the temperature sensor Temp-Sensor to obtain a temperature digital signal.

[0097] The temperature value belongs to different ranges, and the corresponding temperature digital signals are different.

[0098] The analog-to-digital converter GPADC plays a vital role in the temperature detection circuit 10. It is responsible for accurately encoding the temperature value captured by the temperature sensor Temp-Sensor to generate the corresponding temperature digital signal. This process ensures the conversion of temperature information from analog form to digital form, providing a basis for subsequent digital processing.

[0099] It is worth noting that different temperature value ranges will result in differences in the temperature digital signal output by the analog-to-digital converter GPADC.

[0100] Specifically, when the temperature value is in a lower range, the analog-to-digital converter GPADC will encode this temperature value into a smaller digital signal based on its internal conversion rules and resolution. This means that the value of the digital signal is lower, reflecting the lower temperature.

[0101] On the contrary, when the temperature value is in a higher range, the analog-to-digital converter GPADC will generate a larger digital signal to represent this high temperature state. The increase in the value of the digital signal directly reflects the increase in temperature.

[0102] This mechanism of generating different digital signals according to the temperature value range ensures the accurate transmission and expression of temperature information. The high precision and stability of the analog-to-digital converter GPADC are crucial to the performance of the temperature detection circuit 10, and together they constitute a reliable and accurate temperature measurement system.

[0103] In practical applications, the selection and design of the analog-to-digital converter GPADC needs to take into account the characteristics, measurement range, resolution and system requirements for temperature accuracy of the temperature sensor Temp-Sensor. Through reasonable configuration and optimization, it can be ensured that the temperature detection circuit 10 can provide accurate and stable temperature measurement results in various environments.

[0104] Optionally, the mapping circuit controls the working states of different resistance units according to different temperature digital signals.

[0105] The mapping circuit intelligently controls the working states of a series of resistance units according to the different temperature digital signals output by the analog-to-digital converter GPADC.

[0106] Specifically, when the analog-to-digital converter GPADC captures a lower temperature value and converts it into a corresponding digital signal, the mapping circuit will selectively activate or adjust the resistance units corresponding to the low temperature range based on this signal. The changes in the working state of these resistance units may be manifested as an increase or decrease in resistance value, thereby reflecting the low temperature level.

[0107] Conversely, when the analog-to-digital converter GPADC detects a higher temperature value and outputs a corresponding digital signal, the mapping circuit will adjust the resistor units associated with the high temperature range accordingly. These resistor units may work in different ways, such as increasing the resistance value in response to the high temperature environment, or reflecting the temperature change by changing the current path in the circuit.

[0108] Through this precise control mechanism, the mapping circuit can ensure that the output of the temperature detection system is highly consistent with the actual temperature value. Different temperature digital signals not only trigger the change of the working state of the resistor unit, but also indirectly adjust the response characteristics of the entire system, so that it can accurately and reliably reflect the changes in ambient temperature.

[0109] In practical applications, the design of the mapping circuit may need to consider a variety of factors, including temperature range, resolution, system stability, power consumption, etc. Through reasonable circuit layout and component selection, it can be ensured that the mapping circuit can provide stable and accurate temperature measurement results under various environmental conditions.

[0110] Optionally, -40°C to 120°C is divided into 16 levels, wherein each 10°C is divided into one level; the temperature value of the analog-to-digital converter GPADC belongs to different levels, and its corresponding temperature digital signal is different; the details are shown in Table 1.

[0111] Table 1: Temperature range

[0112] Junction Temperature (°C) Temp Code Attenuator Value (dB) 120~110 0000 0 110~100 0001 0.35 100~90 0010 0.7 …… …… …… -30~-20 1110 5.25 -40~-30 1111 5.6

[0113] Where, Junction Temperature (°C) is the junction temperature of the power amplifier PA. Temp Code is the temperature code output by the analog-to-digital converter GPADC; Attenuator Value (dB) is the value of the variable resistor circuit R p_array The corresponding attenuation value.

[0114] Digital signals use binary signals, but other situations are of course not excluded, which will not be elaborated here.

[0115] From the above description, we can see that the gain formula is:

[0116]

[0117] For example, -40℃~120℃ is divided into 10℃ steps, totaling 16 steps. After data processing, the analog-to-digital converter GPADC outputs 1111~0000 respectively. If the temperature code is directly mapped to the variable resistor circuit R p_array The control word 1111~0000 corresponds to R p_array，min ~R p_array，max , parallel R LOAD，DA After implementing R LOAD The relative change at high and low temperatures is 0~5.6dB, that is, from low temperature to high temperature R LOAD The changing value compensates for the change in gm.

[0118] The above correspondence between the temperature value range and the gain change is only an example, and the mapping scheme can be flexibly adjusted according to the actual gain change.

[0119] In this embodiment, the temperature sensor Temp-Sensor, the analog-to-digital converter GPADC and the mapping circuit Mapping Circuit are combined to directly bind different temperatures to variable load values ​​by hardware without additional software processing.

[0120] Another embodiment of the present application provides a transmitter.

[0121] See also Figure 1 , the transmitter, comprising: a gain compensation circuit (including Figure 1 10 and R shown p_array ), RF module 20, driving amplifier DA, power amplifier PA, first transformer T1 and second transformer T2.

[0122] The positive and negative electrodes of the output terminal of the RF module 20 are connected to the positive and negative electrodes of the input terminal of the driving amplifier DA.

[0123] Specifically, the positive electrode of the output terminal of the RF module 20 is connected to the positive electrode of the input terminal of the driving amplifier DA, and the negative electrode of the output terminal of the RF module 20 is connected to the negative electrode of the input terminal of the driving amplifier DA.

[0124] The positive and negative output terminals of the RF module 20 are used to output RF signals respectively; the positive and negative input terminals of the driving amplifier DA are connected to the positive and negative output terminals of the RF module 20, thereby receiving the RF signal and performing preliminary amplification.

[0125] The positive and negative electrodes of the output terminal of the driving amplifier DA are connected to the two ends of the primary winding of the first transformer T1.

[0126] Specifically, the positive electrode of the output terminal of the driving amplifier DA is connected to one end of the primary winding of the first transformer T1 ; the negative electrode of the output terminal of the driving amplifier DA is connected to the other end of the primary winding of the first transformer T1 .

[0127] The RF signal after preliminary amplification is output from the positive and negative electrodes of the output terminal of the driving amplifier DA; the two ends of the primary winding of the first transformer T1 are respectively connected to the positive and negative electrodes of the output terminal of the driving amplifier DA, so that the RF signal is transmitted to the first transformer T1 for voltage transformation. That is, the driving amplifier DA is used to pre-amplify the RF signal carrying digital baseband information.

[0128] Two ends of the secondary winding of the first transformer T1 are connected to two ends of the gain compensation circuit and the positive and negative input terminals of the power amplifier PA respectively.

[0129] Specifically, one end of the secondary winding of the first transformer T1 is respectively connected to one end of the gain compensation circuit and the positive input terminal of the power amplifier PA; the other end of the secondary winding of the first transformer T1 is respectively connected to the other end of the gain compensation circuit and the negative input terminal of the power amplifier PA.

[0130] Two ends of the secondary winding of the first transformer T1 are respectively connected to two ends of the gain compensation circuit and the positive and negative input terminals of the power amplifier PA.

[0131] The gain compensation circuit is used to adjust the gain of the RF signal after being transformed by the first transformer T1 to ensure that the amplitude of the signal meets the input requirement of the subsequent power amplifier PA; the adjusted RF signal is sent to the input end of the power amplifier PA for further amplification.

[0132] The positive and negative electrodes of the output terminal of the power amplifier PA are connected to the two ends of the primary winding of the second transformer T2.

[0133] Specifically, the positive electrode of the output terminal of the power amplifier PA is connected to one end of the primary winding of the second transformer T2; the negative electrode of the output terminal of the power amplifier PA is connected to the other end of the primary winding of the second transformer T2.

[0134] The RF signal amplified by the power amplifier PA is output from the positive and negative electrodes of the output terminal. The two ends of the primary winding of the second transformer T2 are respectively connected to the positive and negative electrodes of the output terminal of the power amplifier PA, and the RF signal is transmitted to the second transformer T2 for further voltage transformation. That is, the power amplifier PA is used to further amplify the RF signal carrying digital baseband information to meet the transmission power requirements.

[0135] One end of the secondary winding of the second transformer T2 is grounded.

[0136] The other end of the secondary winding of the second transformer T2 serves as the output end of the transmitter.

[0137] One end of the secondary winding of the second transformer T2 is grounded to provide a stable potential reference and help eliminate electromagnetic interference.

[0138] The radio frequency signal after the voltage transformation by the second transformer T2 is output from the output end of the transmitter for subsequent transmission or application.

[0139] In summary, the connection process involves multiple components including the RF module 20, the driver amplifier DA, the first transformer T1, the gain compensation circuit, the power amplifier PA, the second transformer T2, and the transmitter output terminal. Each component plays an important role to ensure that the RF signal can be transmitted and amplified stably and efficiently.

[0140] In this embodiment, the positive and negative electrodes of the output terminal of the RF module 20 are connected to the positive and negative electrodes of the input terminal of the driving amplifier DA; the positive and negative electrodes of the output terminal of the driving amplifier DA are connected to the two ends of the primary winding of the first transformer T1; the two ends of the secondary winding of the first transformer T1 are respectively connected to the two ends of the gain compensation circuit and the positive and negative electrodes of the input terminal of the power amplifier PA; the positive and negative electrodes of the output terminal of the power amplifier PA are connected to the two ends of the primary winding of the second transformer T2; one end of the secondary winding of the second transformer T2 is grounded; the other end of the secondary winding of the second transformer T2 is used as the output terminal of the transmitter, that is, the fluctuation caused by the temperature change in the transmitter is compensated by the gain compensation circuit, so that the output of the transmitter is relatively stable. In addition, the additional gain compensation circuit does not affect the working state of the TX link core module, and therefore does not affect the performance of the system during normal operation.

[0141] Optionally, the radio frequency module 20 includes: a modem, a signal generator U3, a frequency divider U1, a 90° / 0 phase shifter U2, two digital-to-analog converters, two low-pass filter modules and two mixers.

[0142] The two digital-to-analog converters correspond to the two low-pass filter modules in a one-to-one manner; the two low-pass filter modules correspond to the two mixers in a one-to-one manner.

[0143] The orthogonal I / Q digital signals output by the modem are respectively sent to two digital-to-analog converters. Specifically, the first output end of the modem is connected to the input end of the first digital-to-analog converter DAC1, and the I digital signal is transmitted to the first digital-to-analog converter DAC1. The second output end of the modem is connected to the input end of the second digital-to-analog converter DAC2, and the Q digital signal is transmitted to the second digital-to-analog converter DAC2. The digital-to-analog converter converts the orthogonal I / Q digital signals output by the baseband modem Modem into analog signals.

[0144] The output end of the digital-to-analog converter is connected to the input end of the corresponding low-pass filter.

[0145] The output end of the first digital-to-analog converter DAC1 is connected to the input end of the first low-pass filter LPF1; the output end of the second digital-to-analog converter DAC2 is connected to the input end of the second low-pass filter LPF2. The low-pass filter filters out the DAC image signal and improves the far-end noise.

[0146] The output terminal of the low-pass filter is connected to the first input terminal of the corresponding mixer.

[0147] An output end of the first low-pass filter LPF1 is connected to a first input end of the first mixer MXR1 , and an output end of the second low-pass filter LPF2 is connected to a first input end of the second mixer MXR2 .

[0148] The output terminal of the signal generator U3 is connected to the input terminal of the frequency divider U1.

[0149] The output end of the frequency divider U1 is connected to the input end of the 90° / 0 phase shifter U2.

[0150] The local oscillator signal (Local Oscilator) generates an orthogonal I / Q carrier signal through a divide-by-2 circuit.

[0151] The two output ends of the 90° / 0 phase shifter U2 correspond to the two mixers one by one, and the two output ends of the 90° / 0 phase shifter U2 are connected to the second input ends of the respective corresponding mixers.

[0152] The first output end of the 90° / 0 phase shifter U2 is connected to the second input end of the first mixer MXR1 ; the second output end of the 90° / 0 phase shifter U2 is connected to the second input end of the second mixer MXR2 .

[0153] The phase difference between the signals at the two output ends of the 90° / 0 phase shifter U2 is 90°, that is, the phase of one signal is 0 and the phase of the other signal is 90°. The mixer is used to achieve frequency conversion and convert the analog baseband signal into a radio frequency signal by mixing with a carrier.

[0154] The output end of the mixer serves as the output end of the RF module 20 .

[0155] From the above description, it can be seen that the modem, signal generator U3, divider U1, 90° / 0 phase shifter U2, two digital-to-analog converters (DAC1 and DAC2), two low-pass filter modules (LPF1 and LPF2) and two mixers (Mixer1 and Mixer2) together constitute the key path of signal processing and modulation.

[0156] First, the modem is responsible for outputting orthogonal I / Q digital signals. These two signals are sent to the first digital-to-analog converter DAC1 and the second digital-to-analog converter DAC2 for digital-to-analog conversion. The output ends of the first digital-to-analog converter DAC1 and the second digital-to-analog converter DAC2 are respectively connected to the input ends of the first low-pass filter LPF1 and the second low-pass filter LPF2 to ensure that the converted analog signals are smoothed by the low-pass filters to eliminate high-frequency noise and spurious components.

[0157] Next, the outputs of the first low pass filter LPF1 and the second low pass filter LPF2 are connected to the first inputs of the first mixer MXR1 and the second mixer MXR2, respectively. These filtered analog signals are now ready to be mixed with the local oscillator signal.

[0158] In order to generate a local oscillation signal, the signal generator U3 first outputs a base frequency signal to the divider U1. The divider U1 divides the signal to generate a lower frequency signal, which is then sent to the 90° / 0 phase shifter U2. The function of the 90° / 0 phase shifter U2 is to divide the signal into two paths, one of which maintains the original phase (0°) and the other generates a 90° phase shift. These two signals are used as the second input signals of the first mixer MXR1 and the second mixer MXR2, respectively, to achieve orthogonal modulation.

[0159] Finally, the output ends of the first mixer MXR1 and the second mixer MXR2 are respectively used as two output ends of the radio frequency module 20 to output modulated and mixed radio frequency signals, which can be used for subsequent transmission or further processing.

[0160] The entire system ensures that orthogonal I / Q digital signals can be efficiently converted into RF signals while maintaining signal integrity and quality through carefully designed connections and signal paths.

[0161] The features recorded in the various embodiments in this specification can be replaced or combined with each other, and the same and similar parts between the various embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative work.

[0162] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0163] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transmitter gain temperature compensation circuit, characterized in that: include: Variable resistance circuit and temperature detection circuit; The output end of the temperature detection circuit is connected to the control end of the variable resistance circuit; The variable resistance circuit is connected in parallel with the input terminal of the power amplifier in the transmitter; The temperature detection circuit outputs a control signal to the variable resistance circuit according to the detected temperature to adjust the resistance value of the variable resistance circuit.

2. The transmitter gain temperature compensation circuit according to claim 1, characterized in that: The variable resistance circuit comprises: N resistance units; N is a positive integer; The control end of each of the resistance units serves as the control end of the variable resistance circuit; Both ends of each of the resistor units are connected to the positive and negative input terminals of the power amplifier; The temperature detection circuit controls the working state of each resistance unit according to the detected temperature.

3. The transmitter gain temperature compensation circuit according to claim 2, characterized in that: The resistor unit comprises: a first resistor, a second resistor and a switch tube; One end of the first resistor serves as one end of the resistor unit; The other end of the first resistor is connected to one end of the switch tube; The other end of the switch tube is connected to one end of the second resistor; The other end of the second resistor serves as the other end of the resistor unit; The control end of the switch tube serves as the control end of the resistance unit.

4. The transmitter gain temperature compensation circuit according to claim 1, characterized in that: A temperature detection circuit, comprising: a temperature sensor, an analog-to-digital converter and a mapping circuit; The output end of the temperature sensor is connected to the input end of the analog-to-digital converter; The output end of the analog-to-digital converter is connected to the input end of the mapping circuit; The output end of the mapping circuit serves as the output end of the temperature detection circuit.

5. The transmitter gain temperature compensation circuit according to claim 4, characterized in that: The analog-to-digital converter is used to encode the temperature value of the temperature sensor to obtain a temperature digital signal; The temperature values ​​belong to different ranges, and the corresponding temperature digital signals are different.

6. The transmitter gain temperature compensation circuit according to claim 5, characterized in that: The mapping circuit controls the working states of different resistance units according to different temperature digital signals.

7. The transmitter gain temperature compensation circuit according to claim 5, characterized in that: -40℃~120℃ is divided into 16 levels, where every 10℃ is one level; the temperature values ​​of the analog-to-digital converter belong to different levels, and the corresponding temperature digital signals are different.

8. The transmitter gain temperature compensation circuit according to claim 4, characterized in that: The temperature sensor is placed within a preset range of the power amplifier.

9. A transmitter, characterized in that: include: Gain compensation circuit, radio frequency module, driver amplifier, power amplifier, first transformer and second transformer; The positive and negative electrodes of the output terminal of the radio frequency module are connected to the positive and negative electrodes of the input terminal of the driving amplifier; The positive and negative electrodes of the output terminal of the driving amplifier are connected to the two ends of the primary winding of the first transformer; The two ends of the secondary winding of the first transformer are respectively connected to the two ends of the gain compensation circuit and the positive and negative electrodes of the input end of the power amplifier; The positive and negative electrodes of the output terminal of the power amplifier are connected to the two ends of the primary winding of the second transformer; One end of the secondary winding of the second transformer is grounded; The other end of the secondary winding of the second transformer serves as the output end of the transmitter.

10. The transmitter according to claim 9, characterized in that The radio frequency module includes: a modem, a signal generator, a frequency divider, a 90° / 0 phase shifter, two digital-to-analog converters, two low-pass filter modules and two mixers; The two digital-to-analog converters correspond to the two low-pass filter modules one by one; the two low-pass filter modules correspond to the two mixers one by one; The modem outputs orthogonal I / Q digital signals to the two digital-to-analog converters respectively; The output end of the digital-to-analog converter is connected to the input end of the corresponding low-pass filter; The output end of the low-pass filter is connected to the first input end of the corresponding mixer; The output end of the signal generator is connected to the input end of the frequency divider; The output end of the frequency divider is connected to the input end of the 90° / 0 phase shifter; The two output ends of the 90° / 0 phase shifter correspond to the two mixers one by one, and the two output ends of the 90° / 0 phase shifter are connected to the second input ends of the respective corresponding mixers; The output end of the mixer serves as the output end of the radio frequency module.

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