Time-sharing integrating circuit for satellite-borne radiation receiver and control method

Abstract

The invention discloses a time-sharing integral circuit for a satellite-borne radiation receiver, and the circuit comprises a signal source module which is used for providing different signal sources in an integral mode and an integral holding mode; the operational amplification module comprises a second control switch K2 and an operational amplifier U1, and the second control switch K2 is connected with the input end and the output end of the operational amplifier and used for controlling the time-sharing integral circuit to work in an integral mode or an integral holding mode through the second control switch K2; the first control switch K1 is used for selecting a voltage signal as an input signal; the signal source module, the first control switch K1 and the operational amplifier module are connected in sequence.

Description

Technical Field

[0001] The invention belongs to the technical field of microwave remote sensing radiometer receivers, and in particular relates to a time-sharing integration circuit and a control method for a satellite-borne radiation receiver. Background Art

[0002] Existing active-passive integrated microwave detectors achieve high-resolution, high-precision detection of the target's phase state by collecting passive radiation brightness temperature signals from surface targets and extracting and jointly inverting the characteristics of the target's detection mechanism through backscatter coefficients. However, active detection in active-passive integrated microwave detectors involves actively transmitting high-power signals via radar, while passive detection relies on receiving low-power radiation signals spontaneously emitted by the target. However, high-power signals can significantly interfere with passive detection, leading to deviations in the microwave radiometer's remote sensing data. Furthermore, the integration circuit commonly used in passive detection has a direct impact on the output voltage signal due to its integration time: longer integration times increase the system's sensitivity, but reduce effective spatial resolution and lose some useful information. Summary of the Invention

[0003] To solve the above problems, the present invention proposes a time-sharing integration circuit and control method for a satellite-borne radiation receiver. The present invention designs a circuit with a time-sharing integration holding function and a corresponding calculation output voltage. The system realizes that when the current timing of the active radar is the non-transmitting timing, the integral voltage is output; when the current timing of the active radar is the transmitting timing, the holding voltage is output. The system realizes accurate integration time by reasonably configuring parameters, ensures that the loss rate of the holding voltage output by the circuit is greatly reduced, and ensures the accuracy of the output integral voltage. At the same time, the design of performing different task processing and execution at different timings effectively avoids the interference of high-power signals emitted by the active radar to the satellite-borne radiation receiver.

[0004] A first aspect of the present invention provides a time-sharing integration circuit for a satellite-borne radiation receiver, characterized by comprising: Signal source module, used to provide different signal sources for integration mode and integration hold mode; An operational amplifier module, comprising a second control switch K2 and an operational amplifier U1, wherein the second control switch K2 is connected to the input and output of the operational amplifier, respectively, and is used to control the time-sharing integration circuit to operate in an integration mode or an integration-hold mode through the second control switch K2; A first control switch K1 is used to select a voltage signal as an input signal; The signal source module, the first control switch K1, and the operational amplifier module are connected in sequence.

[0005] Preferably, when the active radar does not transmit a signal, the first control switch K1 selects the radiation receiver detection amplification voltage as the input signal, the second control switch K2 is closed, and the circuit operates in the integration mode.

[0006] Preferably, it is characterized in that, when the active radar transmits a signal, the first control switch K1 selects the reference voltage as the input signal, the second control switch K2 is disconnected, and the circuit operates in the integration and holding mode.

[0007] Preferably, the operational amplifier module also includes a first resistor R1, a third resistor R3, a fifth resistor R5, and a fourth resistor R4. The inverting input terminal of the operational amplifier U1 is connected to the first resistor R1 and the third resistor R3 connected in series. The non-inverting input terminal of the operational amplifier U1 is connected to the fourth resistor R4 and grounded. The output terminal of the operational amplifier U1 is connected to the fifth resistor R5.

[0008] Preferably, the operational amplifier module also includes an integrating resistor R2 and an integrating capacitor C, one end of the integrating resistor R2 is connected to the inverting input terminal of the operational amplifier module U1, the other end of the integrating resistor R2 is connected in series with the second control switch K2 and then connected in parallel with the integrating capacitor C to form a parallel group, one end of the parallel group is connected to the common end of the first resistor R1 and the integrating resistor R2, and the other end of the parallel group is connected to the output terminal of the operational amplifier U1.

[0009] Preferably, it is characterized in that the signal source module includes a reference voltage and a radiation receiver detection amplification voltage; the first control switch K1 is a single-pole double-throw electronic switch, and the second control switch K2 is an electronic switch.

[0010] Preferably, it is characterized in that the integrating capacitor C adopts a 1uF ceramic capacitor, the operational amplifier U1 adopts OP270, the power supply voltage of the operational amplifier U1 is ±12V, the sum of the on-resistance of the second control switch K2 and the integrating resistor R2 adopts 5KΩ, and the off-resistance of the second control switch K2 is greater than 1MΩ.

[0011] Based on the same concept as above, a second aspect of the present invention provides a method for controlling a time-sharing integration circuit for a satellite-borne radiation receiver, characterized in that it includes the following steps: If the active radar is not transmitting a signal, it is in the integration mode, the first control switch K1 selects the radiation receiver detection amplification voltage, and the second control switch K2 is closed and outputs the integration voltage; If the active radar is in the integration and holding mode when transmitting a signal, the first control switch K1 selects the reference voltage, disconnects the second control switch K2 and outputs the integration and holding voltage.

[0012] Preferably, the step of outputting the integral holding voltage further comprises: Construct the circuit equation and calculate the expression: Where C is the integral capacitor, u i is the reference voltage, which is preset to 0V, R1 is the first resistor, u o is the output of the circuit, in this mode it is the integral holding voltage, u c is the voltage across the integrating capacitor; Based on the circuit equation, the variation equation is obtained and the calculation expression is: Based on the variation equation, the output voltage is obtained by solving the equation and calculating the expression: u in the formula o保持 (0) is the output voltage at the switching moment, which is the holding voltage.

[0013] Preferably, the step of outputting the integrated voltage further comprises: The preset integration time is 10ms; Construct the integration circuit equation and calculate the expression: Where C is the integral capacitor, R1 is the first resistor, u o is the output of the circuit, which is the integral voltage in this mode, R 积分 is the total resistance of the closing resistance of the first control switch K1 and the integral resistance R2, u c is the voltage across the integrating capacitor C; Based on the integration circuit equation, the differential equation of the integrated voltage is obtained, and the calculation expression is: The integral voltage is obtained by solving the differential equation based on the integral voltage, and the calculation expression is: u in the formula o积分 (0) is the output voltage at the switching moment.

[0014] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art: The present invention designs a time-sharing integration circuit including a signal source module, an operational amplifier module, and a first control switch K1. The current of the active radar is the transmission timing, and the working mode of the time-sharing integration circuit is Integrate and hold mode, outputting a hold voltage. The active radar is currently not transmitting, and the time-sharing integration circuit operates in integration mode and outputs an integrated voltage. This circuit design effectively prevents large signals emitted by the active radar from interfering with the data of the passive radiation receiving system, ensuring the accuracy of the data output by the system.

[0015] The system of the present invention proposes a time-sharing integration circuit, which achieves high accuracy, high sensitivity and effective spatial resolution of low-power radiation signal data. The parameters of the time-sharing integration circuit are designed (such as the parameters of resistance and capacitance) to achieve accurate integration time in the integration mode. The output voltage loss in the integration hold mode is greatly reduced and far lower than the sensitivity of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein: Figure 1 A schematic diagram of a system configuration for receiving low-power radiation in the present invention; Figure 2 Schematic diagram of the equivalent circuit of the system in the integration mode of the present invention; Figure 3 Schematic diagram of the equivalent circuit of the system in the integral holding mode of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are greatly simplified and not to exact ratios, and are intended solely to facilitate and clearly illustrate the embodiments of the present invention.

[0018] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0019] First embodiment See also Figure 1 、 Figure 2 and Figure 3In a first aspect, the present invention provides a time-sharing integration circuit for a satellite-borne radiation receiver, characterized in that it includes: a signal source module, which is used to provide different signal sources in an integration mode and an integration-hold mode; an operational amplifier module, which includes a second control switch K2 and an operational amplifier U1, wherein the second control switch K2 is respectively connected to the input and output terminals of the operational amplifier and is used to control the time-sharing integration circuit to operate in the integration mode or the integration-hold mode through the second control switch K2; a first control switch K1, which is used to select a voltage signal as an input signal; the signal source module, the first control switch K1, and the operational amplifier module are connected in sequence.

[0020] In this embodiment, the signal source module includes a reference voltage V ref and radiation receiver detection amplifier voltage V j , where the radiation receiver detection amplifier voltage is the result obtained by receiving the spontaneous radiation information of the surface target object through detection and amplification processing, and the reference voltage V ref The first control switch K1 is used to select different signal sources. Specifically, when the circuit is in the integration and holding mode, the first control switch selects to connect the reference voltage to provide a reference voltage for the time-sharing integration circuit. When the circuit is in the integration mode, the first control switch selects to connect the radiation receiver detection amplification voltage to provide a signal voltage for the time-sharing integration circuit. The operational amplifier module includes a first resistor R1, an operational amplifier U1, a third resistor R3, a fourth resistor R4, and a fifth resistor R5. The integration and holding module includes an integration capacitor C, a second control switch K2, and an integration resistor R2; specifically connected: signal source module, first control switch K1, first resistor R1, third resistor R 3、 The inverting input terminal of the operational amplifier U1 is sequentially connected in series, and the two ends of the series connection of the integrating resistor R2 and the second control switch K2 are connected in parallel with the integrating capacitor C to form a parallel group. One end of the parallel group is connected to the common end of the first resistor R1 and the integrating resistor R2, and the other end of the parallel group is connected to the output terminal of the operational amplifier U1. The output terminal of the operational amplifier U1 is connected to one end of the fifth resistor R5. The other end of the fifth resistor R5 serves as the output terminal of the time-sharing integration circuit. In the integration mode, the output terminal of the time-sharing integration circuit outputs an integrated voltage, and in the integration-hold mode, the output terminal of the time-sharing integration circuit outputs an integrated hold voltage. A non-inverting input terminal of the operational amplifier U1 is connected to the fourth resistor R4 and is grounded.

[0021] Regarding the selection of components in the system, it is preferred that R2>R1. In this embodiment, the following can be selected: R1 is 4.7 KΩ, R2 is 4.9 KΩ, R3 is 1 MΩ, the integral capacitor C is a ceramic capacitor and is selected as 1uF, and the operational amplifier U1 is OP270, whose power supply voltage is ±12V. The first control switch K1 is a single-pole double-throw switch. The first control switch K1 and the second control switch K2 are both electronic switches. The on-resistance of the two control switches is about 100Ω, and the off-resistance is greater than 1 MΩ. The radiation receiver detection amplifier voltage V j It is the voltage value of the radiation information of the surface target object after detection and amplification. The reference voltage is V ref Indicates that the input voltage in the integral mode is V j , where V j In this embodiment, the range that can be selected is -10V~+10V. The default setting is 0V.

[0022] There are two working modes for this system: integration mode and integration hold mode. If the active radar timing is not transmitting, the system is in integration mode, the first control switch K1 of the selection module is connected to the radiation receiver detection amplification voltage, and the second control switch K2 is closed. Considering that the on-resistance of K2 is about 100Ω when it is closed, the corresponding equivalent circuit reference Figure 2 If the active radar is transmitting, the system is in the integration and holding mode, and the first control switch K1 is connected to the reference voltage V ref , disconnect the second control switch K2, the off resistance of the second control switch K2 is greater than 1MΩ, and its equivalent circuit can be referred to Figure 3 .

[0023] Based on the above considerations, in this embodiment, the operational amplifier U1 is OP270, whose power supply voltage is ±12V. Optionally, the third resistor R3 is 1MΩ.

[0024] The first control switch K1 and the second control switch K2 are both electronic switches. The on-resistance of the two control switches is about 100Ω, and the off-resistance is greater than 1MΩ. Optionally, the third resistor R3 is 1MΩ.

[0025] Due to the wide operating temperature range of the system, the temperature drift characteristics of the on-resistance of the first control switch K1 and the second control switch K2 affect the accuracy of the integration time of the time-sharing integration circuit in the integration state. The larger the value of the integration resistor R2, the greater the change in the on-resistance of the second control switch K2 with temperature. 积分 Therefore, in order to improve the accuracy of the integral time, it is necessary to select a larger integral resistor R2 and a smaller integral capacitor C. 保持 C is negatively correlated with R保持 The value in the integration hold mode is approximately equal to the off resistance value of the second control switch K2. The larger the integration capacitor C, the smaller the voltage loss value in the integration hold mode. Therefore, in order to ensure the accuracy of the radiation signal output data, it is necessary to select a small integration resistor R2 and a large integration capacitor C. In the integration hold state, R 保持 The input voltage is in the MΩ range, close to the magnitude of the operational amplifier pin-to-ground resistance. Therefore, the impact of the integrating capacitor discharging through the operational amplifier pin on the output voltage loss during the integration-and-hold state needs to be considered. Therefore, a large resistor, R4, greater than 1 MΩ, is connected in series with the operational amplifier input pin to minimize the rate of discharge through the operational amplifier input pin during the integration-and-hold state. Considering the accuracy of the radiation signal output data, detection sensitivity, and effective spatial resolution, the circuit parameters are selected to ensure accurate integration time in the system's integration mode, with the output voltage loss during the integration-and-hold mode significantly reduced to a minimum.

[0026] See also Figure 2 Preferably, when the active radar does not transmit a signal, the first control switch selects the radiation receiver detection amplification voltage as the input signal, the second control switch is closed, and the circuit operates in the integration mode.

[0027] See also Figure 3 Preferably, when the active radar transmits a signal, the first control switch K1 selects the reference voltage as the input signal, the second control switch K2 is disconnected, and the circuit operates in the integration and holding mode.

[0028] Based on the low-power radiation signal, the radiation receiver detection amplification voltage V is obtained through detection amplification. j , the reference voltage is a preset constant voltage source, which is preset to 0V. For the equivalent circuit, see Figure 3 .

[0029] See also Figure 1 Preferably, the operational amplifier module also includes a first resistor R1, a third resistor R3, a fifth resistor R5, and a fourth resistor R4. The inverting input terminal of the operational amplifier U1 is connected to the first resistor R1 and the third resistor R3 connected in series. The non-inverting input terminal of the operational amplifier U1 is connected to the fourth resistor R4 and grounded. The output terminal of the operational amplifier U1 is connected to the fifth resistor R5.

[0030] Continue to see Figure 1 Preferably, the operational amplifier module further includes an integrating resistor R2 and an integrating capacitor C, one end of the integrating resistor R2 is connected to the inverting input terminal of the operational amplifier module U1, the other end of the integrating resistor R2 is connected in series with the second control switch K2 and then connected in parallel with the integrating capacitor C to form a parallel group, one end of the parallel group is connected to the common end of the first resistor R1 and the integrating resistor R2, and the other end of the parallel group is connected to the output terminal of the operational amplifier U1.

[0031] Preferably, the signal source module includes a reference voltage and a radiation receiver detection amplification voltage; the first control switch K1 is a single-pole double-throw electronic switch, and the second control switch K2 is an electronic switch.

[0032] Preferably, the integrating capacitor C is a 1uF ceramic capacitor, the operational amplifier U1 is OP270, the supply voltage of the operational amplifier U1 is ±12V, the sum of the on-resistance of the second control switch K2 and the integrating resistor R2 is 5KΩ, and the off-resistance K2 of the second control switch is greater than 1MΩ.

[0033] Optionally, the on-resistance of the second control switch K2 is 100Ω.

[0034] Optionally, the on-resistance of the first control switch K1 is 100Ω.

[0035] Optionally, the integrating resistor R2 is greater than the first resistor R1. Optionally, the integrating resistor R2 can be 4.9 KΩ.

[0036] Second embodiment See also Figure 2 and Figure 3 Based on the same concept as above, the second aspect of the present invention provides a control method for a time-sharing integration circuit for a satellite-borne radiation receiver, characterized in that it includes the following steps: If the active radar is not transmitting a signal, it is in the integration mode, the first control switch K1 selects the radiation receiver detection amplification voltage, and the second control switch K2 is closed and outputs the integration voltage; If the active radar is in the integration hold mode when transmitting the signal, the first control switch K1 selects The reference voltage is turned off, the second control switch K2 is turned off, and the integration holding voltage is output.

[0037] Specifically, the equivalent circuit of the integral hold mode can be found in Figure 3 , the equivalent circuit of the integral mode can be found in Figure 2 .

[0038] The specific process of the integration mode is as follows: the first control switch K1 selects the radiation receiver detection amplifier voltage to be connected, and the second control switch K2 is set to a closed state; Figure 2 The equivalent circuit shown in the figure obtains the integrated voltage, and the calculation expression of the integrated voltage is: Since the time constant τ = R 积分 C, where R 积分 is the total on-resistance of R2 and the second control switch K2; 积分 is 5KΩ, C is 1uF, and the integration time is preset to twice the time constant, which is 10ms.

[0039] In this embodiment, the working cycle of the associated radar can be set to 500us, including a timing of 475us when no signal is transmitted and a timing of 25us when a signal is transmitted.

[0040] Refer to the equivalent circuit of the integral hold mode Figure 3 , the first control switch K1 of the signal processing module selects the reference voltage V ref connected, the second control switch K2 is set to the disconnected state; based on the reference voltage V ref The calculation expression for obtaining the output integral voltage is: Based on the above, one integration time includes 20 active radar working cycles, where one working cycle includes a non-transmitting signal sequence of 475us and a transmitting signal sequence of 25us. The calculation expression for the maximum loss △u0 of the integral holding voltage within one integration time is: u in the formula o It is the output voltage at normal temperature.

[0041] The sensitivity of the system to the output voltage is 9.3 mV, and the output voltage loss introduced by the integration of this design scheme within an integration time is less than 1.6% of the sensitivity of the radiometer.

[0042] Preferably, the step of outputting the integral holding voltage further comprises: Construct the circuit equation and calculate the expression: Where C is the integral capacitor, u i is the reference voltage, preset to 0V, R1 is the first resistor, u o is the output of the circuit, in this mode it is the integral holding voltage, u c is the voltage across the integrating capacitor; Based on the circuit equation, the variation equation is obtained and the calculation expression is: Based on the variation equation, the output voltage is obtained by solving the equation and calculating the expression: u in the formula o保持 (0) is the output voltage at the switching moment, which is the holding voltage.

[0043] Equivalent circuit see Figure 3According to the "virtual-off" principle of the operational amplifier, the current flowing through the non-inverting input terminal of the operational amplifier is equal to the current flowing through the output terminal of the operational amplifier. The branch where the integrating resistor R2 and the second control switch K2 are located is approximately disconnected. The circuit equation in the hold mode is obtained. Based on the circuit equation, the general solution for the hold voltage is obtained, and the calculation expression is: Based on the general solution and the output voltage u at t=0 o保持 (0) Solve A2; Obtain the holding voltage based on A2 and the general solution.

[0044] Preferably, the step of outputting the integrated voltage further comprises: The preset integration time is 10ms; Construct the integration circuit equation and calculate the expression: Where C is the integral capacitor, R1 is the first resistor, u o is the output of the circuit, which is the integral voltage in this mode, R 积分 is the total resistance of the closing resistance of the first control switch K1 and the integral resistance R2, u c is the voltage across the integrating capacitor C; Based on the integration circuit equation, the differential equation for the integrated voltage is obtained, and the calculation expression is: The integral voltage is obtained by solving the differential equation based on the integral voltage. The calculation expression is: u in the formula o积分 (0) is the output voltage at the switching moment.

[0045] Equivalent circuit see Figure 2 The integral voltage acquisition process is based on the "virtual short" principle of the operational amplifier, where the voltages at the non-inverting input and the inverting input are equal; and based on the "virtual open" principle of the operational amplifier, where the current flowing through the non-inverting input and the current flowing through the output of the operational amplifier are equal, constructing the integral circuit equation. The general solution expression based on the differential equation of the integral voltage is: Based on the general solution and the output voltage u at t=0 o积分 (0) Solve A1; Obtain the integrated voltage based on A1 and the general solution.

[0046] In the description of this application, it should be noted that the terms "inner" and "outer" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended solely to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" and the like are used solely for distinction and should not be construed as indicating or implying relative importance.

[0047] It should also be noted that, unless otherwise expressly specified or limited, the terms "disposed" and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0048] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the identification content specifically executed by the above-described system and device can refer to the corresponding process in the aforementioned method embodiment.

[0049] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the scope of protection of the present invention.

Claims

1. A time-sharing integration circuit for a satellite-borne radiation receiver, characterized in that: include: Signal source module, used to provide different signal sources for integration mode and integration hold mode; An operational amplifier module, comprising a second control switch K2 and an operational amplifier U1, wherein the second control switch K2 is connected to the input and output of the operational amplifier, respectively, and is used to control the time-sharing integration circuit to operate in an integration mode or an integration-hold mode through the second control switch K2; A first control switch K1 is used to select a voltage signal as an input signal; The signal source module, the first control switch K1, and the operational amplifier module are connected in sequence.

2. The time-sharing integration circuit for a satellite-borne radiation receiver according to claim 1, characterized in that: When the active radar does not transmit a signal, the first control switch K1 selects the radiation receiver detection amplification voltage as the input signal, the second control switch K2 is closed, and the circuit operates in the integration mode.

3. The time-sharing integration circuit for a satellite-borne radiation receiver according to claim 1, characterized in that: When the active radar transmits a signal, the first control switch K1 selects the reference voltage as the input signal, the second control switch K2 is disconnected, and the circuit operates in the integration and holding mode.

4. The time-sharing integration circuit for a satellite-borne radiation receiver according to claim 1, characterized in that: The operational amplifier module also includes a first resistor R1, a third resistor R3, a fifth resistor R5, and a fourth resistor R4. The inverting input terminal of the operational amplifier U1 is connected to the first resistor R1 and the third resistor R3 connected in series. The non-inverting input terminal of the operational amplifier U1 is connected to the fourth resistor R4 and grounded. The output terminal of the operational amplifier U1 is connected to the fifth resistor R5.

5. The time-sharing integration circuit for a satellite-borne radiation receiver according to claim 1, characterized in that: The operational amplifier module also includes an integrating resistor R2 and an integrating capacitor C. One end of the integrating resistor R2 is connected to the inverting input terminal of the operational amplifier module U1. The other end of the integrating resistor R2 is connected in series with the second control switch K2 and then connected in parallel with the integrating capacitor C to form a parallel group. One end of the parallel group is connected to the common end of the first resistor R1 and the integrating resistor R2, and the other end of the parallel group is connected to the output terminal of the operational amplifier U1.

6. The time-sharing integration circuit for a satellite-borne radiation receiver according to claim 1, characterized in that: The signal source module includes a reference voltage and a radiation receiver detection amplification voltage; the first control switch K1 is a single-pole double-throw electronic switch, and the second control switch K2 is an electronic switch.

7. The time-sharing integration circuit for a satellite-borne radiation receiver according to claim 5, characterized in that: The integrating capacitor C is a 1uF ceramic capacitor, the operational amplifier U1 is OP270, the supply voltage of the operational amplifier U1 is ±12V, the sum of the on-resistance of the second control switch K2 and the integrating resistor R2 is 5KΩ, and the off-resistance of the second control switch K2 is greater than 1MΩ.

8. A method for controlling a time-sharing integration circuit for a satellite-borne radiation receiver according to any one of claims 1 to 7, characterized in that: The steps include: If the active radar is not transmitting a signal, it is in the integration mode, the first control switch K1 selects the radiation receiver detection amplification voltage, and the second control switch K2 is closed and outputs the integration voltage; If the active radar is in the integration and holding mode when transmitting a signal, the first control switch K1 selects the reference voltage, disconnects the second control switch K2 and outputs the integration and holding voltage.

9. The control method of the time-sharing integration circuit for a satellite-borne radiation receiver according to claim 8, characterized in that: The step of outputting the integral hold voltage further comprises: Construct the circuit equation and calculate the expression: Where C is the integral capacitor, u i is the reference voltage, which is preset to 0V, R1 is the first resistor, u o is the output of the circuit, in this mode it is the integral holding voltage, u c is the voltage across the integrating capacitor; Based on the circuit equation, the variation equation is obtained and the calculation expression is: Based on the variation equation, the output voltage is obtained by solving the equation and calculating the expression: u in the formula o保持 (0) is the output voltage at the switching moment, which is the holding voltage.

10. The control method of the time-sharing integration circuit for a satellite-borne radiation receiver according to claim 8, characterized in that: The step of outputting the integrated voltage further comprises: The preset integration time is 10ms; Construct the integration circuit equation and calculate the expression: Where C is the integral capacitor, R1 is the first resistor, u o is the output of the circuit, which is the integral voltage in this mode, R 积分 is the total resistance of the closing resistance of the first control switch K1 and the integral resistance R2, u c is the voltage across the integrating capacitor C; Based on the integration circuit equation, the differential equation of the integrated voltage is obtained, and the calculation expression is: The integral voltage is obtained by solving the differential equation based on the integral voltage, and the calculation expression is: u in the formula o积分 (0) is the output voltage at the switching moment.

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