Temperature compensation circuit and temperature compensation attenuator

Abstract

The utility model discloses a temperature compensation circuit and a temperature compensation attenuator, and relates to the technical field of electronics. The control end of the switching tube module is connected with the voltage input end; the first end of the switching tube module is connected with the positive electrode of the radio frequency input signal port and is connected with the positive electrode of the radio frequency output signal port; the second end of the switching tube module is connected with the negative electrode of the radio frequency input signal port and is connected with the negative electrode of the radio frequency output signal port. A switch tube module is adopted to replace a T-type attenuator structure and a Pi-type attenuator structure of a traditional attenuation structure, and the principle that equivalent resistance is different under different bias voltages of switch tubes in the switch tube module is mainly adopted to achieve attenuation. Compared with a traditional attenuation architecture, series devices and corresponding parasitic capacitors on a signal path are removed, the attenuation amount is effectively controlled to a certain extent, insertion loss is reduced, and the working bandwidth is increased.

Description

Technical Field

[0001] The utility model relates to the field of electronic technology, in particular to a temperature compensation circuit and a temperature compensation attenuator. Background Art

[0002] To address the problem of large gain fluctuations in phased array systems at different temperatures, a temperature compensation circuit is usually added for calibration.

[0003] Traditional temperature compensation technology is implemented with a T-type or Pi-type attenuator structure, but resistor elements are connected in series in the signal path. Resistor elements often have parasitic capacitance, making high-frequency signals sensitive to capacitor parasitics. The corresponding high-frequency insertion loss will cause a certain deterioration, resulting in ultra-wideband being blocked and limited at high frequencies.

[0004] Therefore, how to reduce the insertion loss of the circuit and improve the working bandwidth of the attenuator is a technical problem that technical personnel in this field urgently need to solve. Utility Model Content

[0005] The utility model aims to provide a temperature compensation circuit and a temperature compensation attenuator to solve the technical problems that the resistance elements connected in series in the traditional attenuator lead to high insertion loss and limited working bandwidth.

[0006] In order to solve the above technical problems, the utility model provides a temperature compensation circuit, the temperature compensation circuit includes a switch tube module;

[0007] The control end of the switch tube module is connected to the voltage input end;

[0008] The first end of the switch tube module is connected to the positive pole of the RF input signal port, and is also connected to the positive pole of the RF output signal port;

[0009] The second end of the switch tube module is connected to the negative pole of the RF input signal port, and is also connected to the negative pole of the RF output signal port;

[0010] The switch tube module is used for turning on the switch tube in the switch tube module when the input voltage at the voltage input end is greater than 0V, and using the equivalent resistance formed by the conduction of the switch tube to change the signal amount at the RF input signal port and the RF output signal port to adjust the attenuation amount;

[0011] Wherein, if the switch tube module includes a first switch tube, and the number of the first switch tube is one; the control end of the first switch tube serves as the control end of the switch tube module; the first end of the first switch tube serves as the first end of the switch tube module; and the second end of the first switch tube serves as the second end of the switch tube module;

[0012] If the switch tube module includes N second switch tubes, and N is a positive integer greater than 1; the control ends of the N second switch tubes are all connected to the voltage input end; the second end of the i-th second switch tube is connected to the first end of the i+1-th second switch tube; wherein 0<i<N; the first end of the first second switch tube serves as the first end of the switch tube module; the second end of the last second switch tube serves as the second end of the switch tube module.

[0013] On the one hand, it also includes isolation resistors, wherein the number of the isolation resistors is the same as the number of switch tubes of the switch tube module and corresponds one-to-one with the switch tubes;

[0014] The first end of each isolation resistor is correspondingly connected to the control end of each switch tube;

[0015] The second end of each isolation resistor is connected to the voltage input end.

[0016] On the other hand, it further includes first resistors; wherein the number of the first resistors is the same as the number of switch tubes of the switch tube module, and corresponds one-to-one with the switch tubes;

[0017] If the switch tube module includes a first switch tube, the first end of the first resistor is connected to the first end of the first switch tube; the second end of the first resistor is connected to the second end of the first switch tube;

[0018] If the switch tube module includes N second switch tubes, the first resistors are connected in sequence, and the second end of the mth first resistor, the first end of the m+1th first resistor, the second end of the i-th second switch tube and the first end of the i+1th second switch tube are all connected; the first end of the first first resistor is connected to the first end of the first second switch tube, and the second end of the last first resistor is connected to the second end of the last second switch tube; wherein, 0<m<N.

[0019] On the other hand, it also includes a first temperature adaptive bias circuit, wherein the first temperature adaptive bias circuit includes a first positive temperature coefficient resistor and a first negative temperature coefficient resistor;

[0020] The first end of the first positive temperature coefficient resistor is connected to the voltage input end; the second end of the first positive temperature coefficient resistor is connected to the first end of the first negative temperature coefficient resistor and is connected to the first end of the isolation resistor;

[0021] The second end of the first negative temperature coefficient resistor is connected to the second end of the switch tube module.

[0022] On the other hand, the first positive temperature coefficient resistor includes at least a first sub-resistor and a second sub-resistor; the first negative temperature coefficient resistor includes at least a third sub-resistor and a fourth sub-resistor;

[0023] The first end of the first sub-resistor is connected to the voltage input end; the second end of the first sub-resistor is connected to the first end of the second sub-resistor; the second end of the second sub-resistor is connected to the first end of the isolation resistor;

[0024] The first end of the third sub-resistor is connected to the first end of the isolation resistor; the second end of the third sub-resistor is connected to the first end of the fourth sub-resistor; and the second end of the fourth sub-resistor is connected to the second end of the switch tube module.

[0025] On the other hand, it also includes a stacked voltage-dividing branch, wherein the stacked voltage-dividing branch includes P stacked sub-voltage-dividing branches;

[0026] Among them, the first end of each stacked sub-voltage-dividing branch is connected to the second end of each resistor of the first positive temperature coefficient resistor; the second end of each stacked sub-voltage-dividing branch is connected to the second end of the switch tube module.

[0027] On the other hand, each of the stacked sub-voltage-dividing branches includes Q third switch tubes, where Q is a positive integer;

[0028] The first end of the qth third switch tube is connected to the control end; the second end of the qth third switch tube is connected to the first end of the q+1th third switch tube;

[0029] The first end of the first third switch tube serves as the first end of the stacked sub-voltage-dividing branch, and the second end of the last third switch tube serves as the second end of the stacked sub-voltage-dividing branch; wherein 0<q<Q;

[0030] Each third switch tube of the stacked sub-voltage divider branch connected to the first negative temperature coefficient resistor corresponds one-to-one to each resistor of the first negative temperature coefficient resistor, and the two ends of each resistor of the first negative temperature coefficient resistor are correspondingly connected to the first end and the second end of each third switch tube.

[0031] On the other hand, each of the stacked sub-voltage-dividing branches includes M first diodes, where M is a positive integer;

[0032] The cathode of the mth first diode is connected to the anode of the m+1th first diode;

[0033] The anode of the first first diode serves as the first end of the stacked sub-voltage-dividing branch, and the cathode of the last first diode serves as the second end of the stacked sub-voltage-dividing branch; wherein 0<m<M;

[0034] Each first diode of the stacked sub-voltage divider branch connected to the first negative temperature coefficient resistor corresponds to each resistor of the first negative temperature coefficient resistor, and both ends of each resistor of the first negative temperature coefficient resistor are correspondingly connected to the anode and cathode of each first diode.

[0035] On the other hand, it also includes a second temperature adaptive bias circuit; the second temperature adaptive bias circuit includes a second resistor and a fourth switch tube;

[0036] The first end of the second resistor is connected to the current input end and connected to the control end of the fourth switch tube; the second end of the second resistor is connected to the second end of the switch tube module;

[0037] The first end of the fourth switch tube is connected to the voltage input end;

[0038] The second end of the fourth switch tube is connected to the second end of the switch tube module.

[0039] In order to solve the above technical problems, the utility model also provides a temperature compensation attenuator, including the temperature compensation circuit described above.

[0040] The utility model provides a temperature compensation circuit, the temperature compensation circuit includes a switch tube module; the control end of the switch tube module is connected to the voltage input end; the first end of the switch tube module is connected to the positive pole of the RF input signal port and the positive pole of the RF output signal port; the second end of the switch tube module is connected to the negative pole of the RF input signal port and the negative pole of the RF output signal port; the number of switch tubes in the switch tube module can be one or more, and when the input voltage of the voltage input end is greater than 0V, the switch tube in the switch tube module is turned on, and the equivalent resistance formed by the conduction of the switch tube is used to change the signal quantity of the RF input signal port and the RF output signal port to adjust the attenuation. The utility model adopts a switch tube module to replace the T-type and Pi-type attenuator structure of the traditional attenuation structure, and mainly realizes attenuation based on the principle that the equivalent resistance of the switch tube in the switch tube module is different under different bias voltages. Compared with the traditional attenuation architecture, the series device and its corresponding parasitic capacitance on the signal path are removed, the attenuation is effectively controlled to a certain extent, the insertion loss is reduced and the working bandwidth is increased. In addition, compared with the traditional active temperature compensation circuit, no operational amplifier is required, the circuit structure is simple, and the power consumption and the area of ​​the circuit main board are reduced.

[0041] In addition, the utility model also provides a temperature compensation attenuator, which has the same beneficial effects as the above-mentioned temperature compensation circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present utility model, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1A structural diagram of a temperature compensation circuit provided by an embodiment of the utility model;

[0044] Figure 2 A structural diagram of a temperature compensation circuit with a differential structure provided by an embodiment of the utility model;

[0045] Figure 3 A structural diagram of a temperature compensation circuit composed of N switching tubes provided in an embodiment of the utility model;

[0046] Figure 4 A structural diagram of another temperature compensation circuit provided by an embodiment of the utility model;

[0047] Figure 5 A structural diagram of a temperature compensation circuit provided by another embodiment of the utility model;

[0048] Figure 6 A schematic diagram of temperature compensation simulation results of a temperature compensation circuit provided by an embodiment of the utility model;

[0049] Figure 7 A schematic diagram of insertion loss simulation results of a temperature compensation circuit provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the utility model.

[0051] The core of the utility model is to provide a temperature compensation circuit and a temperature compensation attenuator to solve the technical problems of high insertion loss and limited working bandwidth caused by the series connection of resistance elements in the traditional attenuator.

[0052] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0053] Traditional temperature compensation circuits are complex in design, have large size and power consumption, and have a narrow bandwidth. Active temperature compensation circuits are generally based on temperature sensitive devices to provide temperature feedback to the system's environment. The error amplifier extracts the error voltage and controls the attenuator to be at different levels of conduction at different temperatures to achieve temperature compensation. Although it has the characteristics of adjustable compensation range and high compensation accuracy, the closed-loop link requires an operational amplifier to generate a temperature error voltage, which will bring additional area and power consumption. The presence of series devices in the signal path of the attenuator structure will seriously deteriorate the insertion loss in the high-frequency band, and the ultra-wideband design will be subject to certain limitations. The temperature compensation circuit provided by the utility model can solve the above technical problems.

[0054] Figure 1 A structural diagram of a temperature compensation circuit provided by an embodiment of the utility model, such as Figure 1 As shown, the temperature compensation circuit includes a switch tube module 1;

[0055] The control end of the switch tube module 1 is connected to the voltage input end Vctrl;

[0056] The first end of the switch tube module 1 is connected to the positive electrode of the radio frequency input signal port RFin, and is connected to the positive electrode of the radio frequency output signal port RFout;

[0057] The second end of the switch tube module 1 is connected to the negative electrode of the radio frequency input signal port RFin, and is connected to the negative electrode of the radio frequency output signal port RFout;

[0058] The switch tube module 1 is used for turning on the switch tube in the switch tube module 1 when the input voltage of the voltage input terminal Vctrl is greater than 0V, and using the equivalent resistance formed by the conduction of the switch tube to change the signal amount of the RF input signal port RFin and the RF output signal port RFout to adjust the attenuation amount;

[0059] Wherein, if the switch tube module 1 includes a first switch tube, and the number of the first switch tube is one; the control end of the first switch tube serves as the control end of the switch tube module 1; the first end of the first switch tube serves as the first end of the switch tube module 1; and the second end of the first switch tube serves as the second end of the switch tube module 1;

[0060] If the switch tube module 1 includes N second switch tubes, and N is a positive integer greater than 1; the control ends of the N second switch tubes are all connected to the voltage input end; the second end of the i-th second switch tube is connected to the first end of the i+1-th second switch tube; wherein 0<i<N; the first end of the first second switch tube serves as the first end of the switch tube module 1; the second end of the last second switch tube serves as the second end of the switch tube module 1.

[0061] Specifically, the switch tube module maintains the conduction process and the shut-down process of the switch tube. The number of corresponding switch tubes in the switch tube module is not limited, and can be one or more. Figure 1 The switch tube module includes two switch tubes (Q1 and Q2), and of course, it can also be one or more than two switch tubes. In addition, in the switch tube module composed of multiple switch tubes, the connection relationship of the multiple switch tubes is stacked.

[0062] The control end of the switch tube module is connected to the voltage input end for receiving the input voltage. The first end of the switch tube module is connected to the positive pole of the RF input signal port and the positive pole of the RF output signal port, and the second end of the switch tube module is connected to the negative pole of the RF input signal port and the negative pole of the RF output signal port. If the input voltage of the voltage input end is 0V, it is directly grounded. At this time, the switch tube of the switch tube module is in the off state and cannot be turned on. The signal path between its RF input signal port and RF output signal port is to the ground, presenting a high impedance state. The attenuation of the RF input signal and RF output signal is minimal during the direct connection process. If the input voltage is greater than 0V, its voltage changes with temperature, so that the switch tube of the switch tube module gradually tends to be turned on, or even saturated, and the signal between the two ports of the RF input signal and the RF output signal is turned on to the ground, and the signal amount between the RF input signal and the RF output signal is reduced, forming a larger attenuation. The corresponding attenuation control is obtained by inputting the input voltage.

[0063] If temperature attenuation is to be achieved, a specific temperature reference value needs to be given, which changes with the temperature to achieve temperature and gain compensation, and its working bandwidth is also increased. Corresponding to the size of the switch tube in the switch tube module, if the input voltage is constant, the larger the size of the switch tube, the greater the attenuation, so that the path to the ground is more thorough. If there are multiple switch tubes, and the sizes of the switch tubes are different, the input voltage is different, and the attenuation can also be controlled. The size of the switch tube in this embodiment, such as the physical parameters corresponding to the gate length and gate width of the transistor. In other words, if you want to achieve attenuation control, you can make adjustments in three aspects: the specific value of the input voltage and the change in the size or type of the switch tube.

[0064] There is no limitation on the type of the switch tube in this embodiment, and it can be considered according to actual conditions, such as field effect tube, MOS tube, etc.

[0065] The negative electrode of the RF input signal terminal and the negative electrode of the RF output signal terminal in this embodiment can be directly grounded, such as Figure 1 The above is only an embodiment, and a differential signal can also be formed by symmetrical connection, which is not limited here. Figure 2 A structural diagram of a temperature compensation circuit of a differential structure provided by an embodiment of the utility model, such as Figure 2As shown, the positive and negative electrodes of the RF input signal port RFin are respectively connected to the first end of the corresponding switch tube module 1; the positive and negative electrodes of the RF output signal port RFout are respectively connected to the first end of the corresponding switch tube module 1; the second end of the switch tube module 1 is grounded, and the voltage input terminal Vctrl is set to two, which are respectively connected to the control end of the switch tube module 1. Figure 2 The mirror structure formed in the embodiment of the present invention. Here, the Rg resistor is an isolation resistor, and the Rp resistor is a first resistor.

[0066] The number of switch tubes in the switch tube module can be limited according to actual conditions. When the number of switch tubes in the switch tube module is one, that is, the first switch tube, the embodiments are as follows:

[0067] The switch tube module includes a first switch tube, and the number of the first switch tube is one;

[0068] The control end of the first switch tube serves as the control end of the switch tube module;

[0069] The first end of the first switch tube serves as the first end of the switch tube module;

[0070] The second end of the first switch tube serves as the second end of the switch tube module.

[0071] Specifically, attenuation is achieved through the first switching tube.

[0072] In addition, there are some embodiments in which there are multiple switch tubes, and the attenuation of the corresponding RF input signal end or RF output signal end achieves voltage division balance. Figure 3 The structure diagram of a temperature compensation circuit composed of N switch tubes provided in an embodiment of the utility model is as follows: Figure 3 As shown, the embodiments are as follows:

[0073] The switch tube module 1 includes N second switch tubes, and N is a positive integer greater than 1;

[0074] The control ends of the N second switch tubes are all connected to the voltage input end Vctrl;

[0075] The second end of the i-th second switch tube is connected to the first end of the i+1-th second switch tube; wherein, 0<i<N; the first end of the first second switch tube serves as the first end of the switch tube module 1; the second end of the last second switch tube serves as the second end of the switch tube module 1.

[0076] In this embodiment, the N second switch tubes connected in parallel stacking can optimize the size of the second switch tube to effectively control the attenuation of the temperature compensation circuit under the same bias, that is, the attenuation device with resistors as the main body of the series device is removed, and only the attenuation control is achieved by connecting N second switch tubes in parallel, so as to effectively reduce the insertion loss of the circuit. On the other hand, while reducing the attenuation device with resistors as the main body, the capacitive parasitic of the circuit is also reduced, the working bandwidth and gain flatness are widened, and the large signal processing capability of the circuit is also improved.

[0077] A temperature compensation circuit provided by the embodiment of the utility model comprises a switch tube module; the control end of the switch tube module is connected to the voltage input end; the first end of the switch tube module is connected to the positive pole of the RF input signal port and the positive pole of the RF output signal port; the second end of the switch tube module is connected to the negative pole of the RF input signal port and the negative pole of the RF output signal port; the number of switch tubes in the switch tube module can be one or more, and when the input voltage of the voltage input end is greater than 0V, the switch tube in the switch tube module is turned on, and the equivalent resistance formed by the conduction of the switch tube is used to change the signal quantity of the RF input signal port and the RF output signal port to adjust the attenuation. The utility model adopts a switch tube module to replace the T-type and Pi-type attenuator structure of the traditional attenuation structure, and mainly realizes attenuation based on the principle that the equivalent resistance of the switch tube in the switch tube module is different under different bias voltages. Compared with the traditional attenuation architecture, the series device and its corresponding parasitic capacitance on the signal path are removed, the attenuation is effectively controlled to a certain extent, the insertion loss is reduced and the working bandwidth is increased. In addition, compared with the traditional active temperature compensation circuit, no operational amplifier is required, the circuit structure is simple, and the power consumption and the area of ​​the circuit main board are reduced.

[0078] In some embodiments, Figure 3 As shown, in order to prevent the AC voltage fed through to the gate of the switch tube from affecting the DC bias of the switch tube, the circuit further includes an isolation resistor Rg, wherein the number of the isolation resistors Rg is the same as the number of the switch tubes of the switch tube module 1, and corresponds one to one with the switch tubes;

[0079] The first end of each isolation resistor Rg is correspondingly connected to the control end of each switch tube;

[0080] The second end of each isolation resistor Rg is connected to the voltage input terminal Vctrl.

[0081] Specifically, Figure 3 As shown, the voltage is input to the voltage input terminal, and the input voltage is transmitted from right to left through the isolation resistor. In order to isolate the conduction of the RF signal from left to right, the RF signal will be connected to the control end of the switch tube. Due to the effect of the isolation resistor, it cannot be conducted with the input voltage, thereby affecting the DC bias of the switch tube.

[0082] It should be noted that the number of switch tubes in the switch tube module can be known from the above embodiments, including a first switch tube and N second switch tubes. Therefore, the number of isolation resistors in this embodiment is the same as the number of switch tubes in the switch tube module, and corresponds one-to-one with the switch tubes. The one-to-one correspondence here means that each isolation resistor is matched with a switch tube, and the first end of the isolation resistor corresponds to the control end of the switch tube, and the second end of the isolation resistor is connected to the voltage input end. In other words, when the number of switch tubes in the switch tube module is one, the number of its isolation resistors is one. When the number of switch tubes in the switch tube module is N, the number of its isolation resistors is N.

[0083] The connection relationship corresponding to the isolation resistor provided in this embodiment prevents the AC voltage fed through to the gate of the switch tube from affecting the DC bias of the switch tube.

[0084] In some embodiments, in order to balance the voltage division of the switch tube to achieve balance, such as Figure 3 As shown, the circuit further includes a first resistor R1; wherein the number of the first resistors R1 is the same as the number of the switch tubes of the switch tube module 1, and corresponds one to one with the switch tubes;

[0085] If the switch tube module 1 includes a first switch tube, the first end of the first resistor R1 is connected to the first end of the first switch tube; the second end of the first resistor R1 is connected to the second end of the first switch tube;

[0086] If the switch tube module 1 includes N second switch tubes, each first resistor R1 is connected in sequence, and the second end of the mth first resistor R1, the first end of the m+1th first resistor R1, the second end of the ith second switch tube and the first end of the i+1th second switch tube are all connected; the first end of the first first resistor R1 is connected to the first end of the first second switch tube, and the second end of the last first resistor R1 is connected to the second end of the last second switch tube; wherein, 0<m<N.

[0087] It should be noted that Figure 3 The number of the first resistors in the circuit is N, namely R11 to R1 N It means that the first resistor is implemented with a positive temperature coefficient, which provides a small amount of temperature compensation effect while balancing the voltage division of the switch tube. With the increase of temperature, the positive temperature coefficient increases, the temperature resistance value increases, and the RF signal to the ground end of the path makes its signal larger and the attenuation is smaller. The first resistor is based on linearity, and increases the processing of large signals so that the voltage division is balanced on the switch tube at both ends of the first resistor.

[0088] The number of first resistors is the same as the number of switch tubes in the switch tube module, and is the same as the number of isolation resistors. If the switch tube module includes a first switch tube, the first end of the first resistor is connected to the first end of the first switch tube, and the second end of the first resistor is connected to the second end of the first switch tube, and is connected in parallel with the first switch tube.

[0089] If the switch tube module includes N second switch tubes, and the first resistors are connected in sequence, the mth first resistor is connected in parallel with the ith second switch tube, that is, the second end of the mth first resistor, the first end of the m+1th first resistor, the second end of the ith second switch tube and the first end of the i+1th second switch tube are all connected. The relationship between m and N here is 0<m<N. The first end of the first first resistor is connected to the first end of the first second switch tube, and the second end of the last first resistor is connected to the second end of the last second switch tube.

[0090] It should be noted that the first resistor has nothing to do with the adjustment of the attenuation amount, and the adjustment of the attenuation amount is only achieved through the switch tube.

[0091] In this embodiment, the number and connection relationship of the first resistors are related to the number of switch tubes corresponding to the switch tube module, and provide a small amount of temperature compensation effect while achieving balanced switch tube voltage division.

[0092] Passive temperature compensation circuits often use resistors with a certain temperature coefficient to implement attenuator structures. The temperature effect of resistors is highly dependent on process consistency, and the compensation range depends on the temperature coefficient of the resistors, and the corresponding temperature adjustable range is limited. Therefore, in some embodiments, the circuit further includes a first temperature adaptive bias circuit, and the first temperature adaptive bias circuit includes a first positive temperature coefficient resistor and a first negative temperature coefficient resistor;

[0093] The first end of the first positive temperature coefficient resistor is connected to the voltage input end; the second end of the first positive temperature coefficient resistor is connected to the first end of the first negative temperature coefficient resistor and is connected to the first end of the isolation resistor;

[0094] The second end of the first negative temperature coefficient resistor is connected to the second end of the switch tube module.

[0095] Specifically, the voltage at the voltage input terminal is changed to adjust the attenuation at room temperature, and the circuit is configured as an adjustable attenuator, and each attenuator gear has a matching temperature compensation effect. It is used to generate a temperature-sensitive voltage Vg to control the switch tube conduction state of the switch tube module to achieve the purpose of temperature compensation. Generally speaking, the active circuit has a gain with a negative temperature coefficient. Taking the loss of the negative temperature coefficient as an example, the consistency of the system gain at different temperatures is improved. The first positive temperature coefficient resistor and the second negative temperature coefficient resistor divide the voltage input terminal at the node Vg, and the first positive temperature coefficient resistor and the second negative temperature coefficient resistor pull down the voltage at the voltage input terminal to reduce its Vg. At high temperatures, the attenuation is weakened, and at low temperatures, the attenuation increases. In the active circuit, if a gain with a positive temperature coefficient is used, it can be applied to the loss of the positive temperature coefficient. When the voltage Vg decreases, the gate voltage of the switch tube module decreases, the attenuator loss is reduced, and the circuit realizes the loss of the adaptive negative temperature coefficient.

[0096] The first end of the first positive temperature coefficient resistor is connected to the voltage input end; the second end of the first positive temperature coefficient resistor is connected to the first end of the first negative temperature coefficient resistor and the first end of the isolation resistor; the second end of the first negative temperature coefficient resistor is connected to the second end of the switch tube module. The first negative temperature coefficient resistor is used to provide a certain temperature compensation and increase the gain compensation of the circuit as a whole within the same temperature range. The gain compensation refers to the range of gain variation within the same temperature range, such as Figure 6 As shown, the gain compensation amount at 0 GHz is -0.014-(-4.54) dB, and the gain compensation amount at 40 GHz is -0.87-(-5.22) dB.

[0097] The number of corresponding resistors in the first positive temperature coefficient resistor and the second negative temperature coefficient resistor is not limited and can be set according to actual conditions. Figure 4 As shown, the first positive temperature coefficient resistor at least includes a first sub-resistor R1' and a second sub-resistor R2'; the first negative temperature coefficient resistor at least includes a third sub-resistor R3' and a fourth sub-resistor R4';

[0098] The first end of the first sub-resistor R1' is connected to the voltage input terminal Vctrl; the second end of the first sub-resistor R1' is connected to the first end of the second sub-resistor R2'; the second end of the second sub-resistor R2' is connected to the first end of the isolation resistor Rg;

[0099] The first end of the third sub-resistor R3 ′ is connected to the first end of the isolation resistor Rg; the second end of the third sub-resistor R3 ′ is connected to the first end of the fourth sub-resistor R4 ′; the second end of the fourth sub-resistor R4 ′ is connected to the second end of the switch tube module 1 .

[0100] Specifically, the series connection relationship between the first sub-resistor and the second sub-resistor in the first positive temperature coefficient resistor and the series connection relationship between the third sub-resistor and the fourth sub-resistor in the first negative temperature coefficient resistor divide the voltage input terminal. The first positive temperature coefficient resistor in this embodiment includes at least the first sub-resistor and the second sub-resistor; the first negative temperature coefficient resistor includes at least the third sub-resistor and the fourth sub-resistor, and the temperature compensation is mainly adjusted by adjusting the input voltage at the voltage input terminal through the voltage dividing effect of the resistor. The temperature compensation here can be adjusted based on the temperature compensation slope, such as when the positive temperature coefficient is 20°C, the corresponding resistance value, and its temperature compensation slope is determined by the linearity between the positive temperature coefficient and the resistor.

[0101] In some embodiments, in order to realize voltage division again, a stacked voltage division circuit is added before the Vg voltage, wherein the stacked voltage division branch includes P stacked sub-voltage division branches;

[0102] The first end of each stacked sub-voltage-dividing branch is connected to the second end of each resistor of the first positive temperature coefficient resistor; the second end of each stacked sub-voltage-dividing branch is connected to the second end of the switch tube module.

[0103] Since the slope of the temperature coefficient of the resistor is limited, the Vg voltage is not low enough to completely shut down the switch tube of the switch tube module at high temperature. Therefore, the stacked reverse voltage circuit is added to combine the resistor series in the first positive temperature coefficient resistor and the resistor series in the first negative temperature coefficient resistor to divide the voltage together. It should be noted that the components in the stacked voltage dividing branch in this embodiment are combined with the above embodiment to achieve a negative temperature coefficient gain.

[0104] The stacked voltage-dividing branch includes P stacked sub-voltage-dividing branches, and the first end of each stacked sub-voltage-dividing branch is connected to the second end of each resistor of the first positive temperature coefficient resistor; the second end of each stacked sub-voltage-dividing branch is connected to the second end of the switch tube module. Limited by the temperature characteristics of the resistor, the traditional temperature compensation attenuator based on pure resistor design has the limitation that the gain compensation amount cannot be adjusted. Figure 4 A structural diagram of another temperature compensation circuit provided by an embodiment of the utility model, such as Figure 4 As shown, each stacked sub-voltage-dividing branch 2 is connected to the second end of each resistor of the first positive temperature coefficient resistor, that is, the first end of the first stacked sub-voltage-dividing branch 2 is connected to the second end of the first sub-resistor R1', and the first end of the second stacked sub-voltage-dividing branch 2 is connected to the second end of the second sub-resistor R2'. The second ends of the first stacked sub-voltage-dividing branch and the second stacked sub-voltage-dividing branch are respectively connected to the second end of the switch tube module 1.

[0105] The number of stacked sub-voltage-dividing branches in the stacked voltage-dividing branch is not limited, and usually, the number of the stacked sub-voltage-dividing branches can be the same as the number of resistors in the first positive temperature coefficient resistor.

[0106] The stacked voltage-dividing branch in this embodiment is further combined with the first positive temperature coefficient resistor and the first negative temperature coefficient resistor to achieve voltage division, further lowering the Vg voltage, and the switch tube is more completely turned off at high temperature.

[0107] In some embodiments, each stacked sub-voltage-dividing branch includes Q third switch tubes, where Q is a positive integer;

[0108] The first end of the qth third switch tube is connected to the control end; the second end of the qth third switch tube is connected to the first end of the q+1th third switch tube;

[0109] The first end of the first third switch tube serves as the first end of the stacked sub-voltage-dividing branch, and the second end of the last third switch tube serves as the second end of the stacked sub-voltage-dividing branch; wherein 0<q<Q;

[0110] Each third switch tube of the stacked sub-voltage dividing branch connected to the first negative temperature coefficient resistor corresponds to each resistor of the first negative temperature coefficient resistor one by one, and both ends of each resistor of the first negative temperature coefficient resistor are correspondingly connected to the first end and the second end of each third switch tube.

[0111] Specifically, Figure 4 As shown, the two stacked sub-voltage-dividing branches include different third switch tubes, which are represented by M1 to M5 respectively. Each stacked sub-voltage-dividing branch includes Q third switch tubes, and the voltage of the first end of the first switch tube of the third switch tube achieves a higher negative temperature coefficient effect than the resistor. The connection relationship between the Q third switch tubes is: the first end of the qth third switch tube is connected to the control end; the second end of the qth third switch tube is connected to the first end of the q+1th third switch tube. In this way, the resistance on the right side of Vg is increased, so that the voltage of Vg is reduced. In addition, the connection relationship between each resistor in the first negative temperature coefficient resistor and the third switch tube between the stacked sub-voltage-dividing branches is: each third switch tube of the stacked sub-voltage-dividing branch connected close to the first negative temperature coefficient resistor corresponds to each resistor of the first negative temperature coefficient resistor one by one, and the two ends of each resistor of the first negative temperature coefficient resistor are correspondingly connected to the first end and the second end of each third switch tube.

[0112] It is understandable that the number of switch tubes stacked in the stacked sub-voltage-dividing branches in this embodiment is not limited, and the number of switch tubes on each stacked sub-voltage-dividing branch may be different or the same. In addition, the size of each third switch tube may be the same or different. This is not limited here.

[0113] In some embodiments, the stacked sub-voltage-dividing circuit may use a diode in addition to the third switch tube. Figure 5 A structural diagram of a temperature compensation circuit provided by another embodiment of the utility model is shown as follows: Figure 5As shown, each stacked voltage-dividing branch 2 includes M first diodes, where M is a positive integer;

[0114] The cathode of the mth first diode is connected to the anode of the m+1th first diode;

[0115] The anode of the first first diode serves as the first end of the stacked sub-voltage-dividing branch 2, and the cathode of the last first diode serves as the second end of the stacked sub-voltage-dividing branch 2; wherein 0<m<M;

[0116] Each first diode of the stacked sub-voltage divider branch 2 connected close to the first negative temperature coefficient resistor corresponds to each resistor of the first negative temperature coefficient resistor, and both ends of each resistor of the first negative temperature coefficient resistor are correspondingly connected to the anode and cathode of each first diode.

[0117] Specifically, Figure 5 As shown, the two stacked voltage-dividing branches include different first diodes, represented by D1 to D5 respectively. The connection relationship of each first diode is the same as the connection relationship of the third switch tube in the above embodiment, which will not be repeated here.

[0118] The connection relationship between the components of each stacked sub-voltage-dividing branch provided in the embodiment of the utility model is to further lower the Vg voltage and turn off the switch tube more thoroughly, thereby compensating for the temperature coefficient slope of the resistor and reducing the insertion loss. The junction voltage temperature characteristic is used in combination with the first positive temperature coefficient resistor and the first negative temperature coefficient resistor to realize the adaptive adjustment of the temperature compensation circuit, eliminating the complex feedback control loop circuit.

[0119] In some embodiments, considering that the high temperature junction voltage of the stacked voltage divider circuit may still cause the switch tube to be in a linear region or a deep linear region, resulting in leakage of the RF signal, therefore, Figure 4 As shown, the circuit also includes a second temperature adaptive bias circuit; the second temperature adaptive bias circuit includes a second resistor R2 and a fourth switch tube M4;

[0120] A first end of the second resistor R2 is connected to the current input end IPTAT and to the control end of the fourth switch tube M4; a second end of the second resistor R2 is connected to the second end of the switch tube module 1;

[0121] A first end of the fourth switch tube M4 is connected to the voltage input end Vctrl;

[0122] The second end of the fourth switch tube M4 is connected to the second end of the switch tube module 1 .

[0123] Specifically, the gate voltage of the control end of the fourth switch tube is determined by the voltage drop of the current input end on the second resistor, and the current of the current input end is provided by the system bandgap. The main function of the bandgap is to provide a stable reference current in the integrated circuit. At this time, the reference needs to be insensitive to changes in the power supply voltage and temperature. The first end of the fourth switch tube is connected to the voltage input end Vg node, and the input current of the current input end is proportional to the temperature. By optimizing the size of the second resistor and the fourth switch tube, the voltage at Vg can be close to 0, and the switch tube of the switch tube module is close to being turned off, which greatly reduces the high temperature loss. By adjusting the input current or the size of the second resistor to adjust the temperature compensation slope, the flexibility and applicability of the circuit are increased. That is to say, the second temperature adaptive bias circuit and the first temperature adaptive bias circuit are in parallel or superimposed and combined. Selecting any temperature adaptive bias circuit can realize temperature compensation for the switch tube of the switch tube module when it is turned on. Secondly, the second temperature adaptive bias circuit has a trimming effect on the gain fluctuation of the first temperature adaptive bias circuit, and has good portability and stability between different processes. The second temperature adaptive bias circuit is used to improve the turn-off performance of the switch tube, reduce the insertion loss problem caused by high temperature, and optimize the linearity between loss and temperature.

[0124] Furthermore, the present invention also provides a temperature compensation attenuator, including the above temperature compensation circuit. For the introduction of the temperature compensation attenuator provided by the present invention, please refer to the above embodiment, which will not be repeated here. It has the same beneficial effects as the above temperature compensation circuit.

[0125] Figure 6 A schematic diagram of a temperature compensation simulation result of a temperature compensation circuit provided by an embodiment of the utility model, such as Figure 6 As shown, the horizontal axis is temperature and the vertical axis is insertion loss (S21). The insertion loss at room temperature is only 1.97~3.02dB. In the temperature range of -55~125℃, 4.40±0.15dB temperature compensation (DC~40GHz) can be provided, and the minimum high temperature loss is only 0.014dB. The insertion loss at 40GHz is also 0.87dB. Figure 7 A schematic diagram of insertion loss simulation results of a temperature compensation circuit provided by an embodiment of the utility model, such as Figure 7 As shown, the horizontal axis is frequency and the vertical axis is insertion loss. At -55 / 25 / 125°C, the frequency range of insertion loss increase of 1dB covers DC~40GHz, and within this frequency range, it can provide 4.35~4.53dB of temperature compensation, and the circuit exhibits good RF broadband characteristics.

[0126] The temperature compensation circuit and temperature compensation attenuator provided by the utility model are introduced in detail above. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the utility model.

[0127] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A temperature compensation circuit, characterized in that: The temperature compensation circuit includes a switch tube module; The control end of the switch tube module is connected to the voltage input end; The first end of the switch tube module is connected to the positive pole of the RF input signal port, and is also connected to the positive pole of the RF output signal port; The second end of the switch tube module is connected to the negative pole of the RF input signal port, and is also connected to the negative pole of the RF output signal port; The switch tube module is used for turning on the switch tube in the switch tube module when the input voltage at the voltage input end is greater than 0V, and using the equivalent resistance formed by the conduction of the switch tube to change the signal amount at the RF input signal port and the RF output signal port to adjust the attenuation amount; Wherein, if the switch tube module includes a first switch tube, and the number of the first switch tube is one; the control end of the first switch tube serves as the control end of the switch tube module; the first end of the first switch tube serves as the first end of the switch tube module; and the second end of the first switch tube serves as the second end of the switch tube module; If the switch tube module includes N second switch tubes, and N is a positive integer greater than 1; the control ends of the N second switch tubes are all connected to the voltage input end; the second end of the i-th second switch tube is connected to the first end of the i+1-th second switch tube; wherein 0<i<N; the first end of the first second switch tube serves as the first end of the switch tube module; the second end of the last second switch tube serves as the second end of the switch tube module.

2. The temperature compensation circuit according to claim 1, characterized in that: It also includes isolation resistors, wherein the number of the isolation resistors is the same as the number of switch tubes of the switch tube module and corresponds one-to-one to the switch tubes; The first end of each isolation resistor is correspondingly connected to the control end of each switch tube; The second end of each isolation resistor is connected to the voltage input end.

3. The temperature compensation circuit according to claim 2, characterized in that: It also includes a first resistor; wherein the number of the first resistors is the same as the number of switch tubes of the switch tube module, and corresponds one-to-one with the switch tubes; If the switch tube module includes a first switch tube, the first end of the first resistor is connected to the first end of the first switch tube; the second end of the first resistor is connected to the second end of the first switch tube; If the switch tube module includes N second switch tubes, the first resistors are connected in sequence, and the second end of the mth first resistor, the first end of the m+1th first resistor, the second end of the i-th second switch tube and the first end of the i+1th second switch tube are all connected; the first end of the first first resistor is connected to the first end of the first second switch tube, and the second end of the last first resistor is connected to the second end of the last second switch tube; wherein, 0<m<N.

4. The temperature compensation circuit according to claim 3, characterized in that: Also included is a first temperature adaptive bias circuit, the first temperature adaptive bias circuit including a first positive temperature coefficient resistor and a first negative temperature coefficient resistor; The first end of the first positive temperature coefficient resistor is connected to the voltage input end; the second end of the first positive temperature coefficient resistor is connected to the first end of the first negative temperature coefficient resistor and is connected to the first end of the isolation resistor; The second end of the first negative temperature coefficient resistor is connected to the second end of the switch tube module.

5. The temperature compensation circuit according to claim 4, characterized in that: The first positive temperature coefficient resistor includes at least a first sub-resistor and a second sub-resistor; the first negative temperature coefficient resistor includes at least a third sub-resistor and a fourth sub-resistor; The first end of the first sub-resistor is connected to the voltage input end; the second end of the first sub-resistor is connected to the first end of the second sub-resistor; the second end of the second sub-resistor is connected to the first end of the isolation resistor; The first end of the third sub-resistor is connected to the first end of the isolation resistor; the second end of the third sub-resistor is connected to the first end of the fourth sub-resistor; and the second end of the fourth sub-resistor is connected to the second end of the switch tube module.

6. The temperature compensation circuit according to claim 4, characterized in that: It also includes a stacked voltage-dividing branch, wherein the stacked voltage-dividing branch includes P stacked sub-voltage-dividing branches; Among them, the first end of each stacked sub-voltage-dividing branch is connected to the second end of each resistor of the first positive temperature coefficient resistor; the second end of each stacked sub-voltage-dividing branch is connected to the second end of the switch tube module.

7. The temperature compensation circuit according to claim 6, characterized in that: Each of the stacked sub-voltage-dividing branches includes Q third switch tubes, where Q is a positive integer; The first end of the qth third switch tube is connected to the control end; the second end of the qth third switch tube is connected to the first end of the q+1th third switch tube; The first end of the first third switch tube serves as the first end of the stacked sub-voltage-dividing branch, and the second end of the last third switch tube serves as the second end of the stacked sub-voltage-dividing branch; wherein 0<q<Q; Each third switch tube of the stacked sub-voltage divider branch connected to the first negative temperature coefficient resistor corresponds one-to-one to each resistor of the first negative temperature coefficient resistor, and the two ends of each resistor of the first negative temperature coefficient resistor are correspondingly connected to the first end and the second end of each third switch tube.

8. The temperature compensation circuit according to claim 6, characterized in that: Each of the stacked sub-voltage-dividing branches includes M first diodes, where M is a positive integer; The cathode of the mth first diode is connected to the anode of the m+1th first diode; The anode of the first first diode serves as the first end of the stacked sub-voltage-dividing branch, and the cathode of the last first diode serves as the second end of the stacked sub-voltage-dividing branch; wherein 0<m<M; Each first diode of the stacked sub-voltage divider branch connected to the first negative temperature coefficient resistor corresponds to each resistor of the first negative temperature coefficient resistor, and both ends of each resistor of the first negative temperature coefficient resistor are correspondingly connected to the anode and cathode of each first diode.

9. The temperature compensation circuit according to claim 4, characterized in that: It also includes a second temperature adaptive bias circuit; the second temperature adaptive bias circuit includes a second resistor and a fourth switch tube; The first end of the second resistor is connected to the current input end and connected to the control end of the fourth switch tube; the second end of the second resistor is connected to the second end of the switch tube module; The first end of the fourth switch tube is connected to the voltage input end; The second end of the fourth switch tube is connected to the second end of the switch tube module.

10. A temperature compensation attenuator, characterized in that: A temperature compensation circuit comprising any one of claims 1 to 9.

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