Pulse modulator and radio frequency power amplifier testing device

Abstract

The utility model discloses a testing device for a pulse modulator and a radio frequency power amplifier, and relates to the field of radio frequency circuits, an input end of a negative voltage detection module is connected in series between a negative voltage output end of a direct current power supply and a grid voltage port of the radio frequency power amplifier, and the negative voltage detection module can detect the voltage condition output from the direct current power supply to the grid voltage port; the control end of the pulse modulation module is connected with the output end of the negative voltage detection module. Only when the voltage detected by the negative voltage detection module is greater than the preset value, i.e., the grid voltage port is confirmed to be powered on, pulse modulation is carried out to power on the drain voltage port of the radio frequency power amplifier. Through cooperation of the negative voltage detection module and the pulse modulation module, it is ensured that the grid voltage port is connected firstly and then the drain voltage port is connected in the power-on process of the radio frequency power amplifier, and therefore the safety and reliability of devices in the radio frequency power amplifier are improved.

Description

Technical Field

[0001] The utility model relates to the field of radio frequency circuits, in particular to a testing device for a pulse modulator and a radio frequency power amplifier. Background Art

[0002] With the continuous development of radio frequency technology, radio frequency power amplifiers are gradually applied in various fields, especially high-power radio frequency power amplifiers used in radio frequency front ends, which have good high-frequency characteristics and can be widely used in radar and satellite TV. In the working process of radio frequency power amplifiers, it is usually necessary to use a DC pulse power supply to achieve low power consumption and high efficiency. Therefore, in the test process before application, the radio frequency power amplifier also needs to use a modulator that can provide high-power DC pulses to power the radio frequency power amplifier, so as to realize the test process of different indicators of the radio frequency power amplifier.

[0003] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a pulse modulator provided by the prior art; the high-power pulse modulator in the prior art directly connects the gate voltage port of the RF power amplifier to be tested to a DC power supply, and the drain voltage port is grounded through an internal electronic switch, and then the DC power supply is modulated into a high-power DC pulse with a stronger load capacity by controlling the rapid opening and closing of the electronic switch inside the instrument, thereby supplying power to the RF power amplifier. However, the power-on process of the RF power amplifier requires connecting the gate voltage port first and then the drain voltage port, and this pulse modulator can only modulate the voltage of the drain voltage port, and cannot guarantee the power-on sequence of the RF power amplifier, which may burn out the components in the RF power amplifier. Utility Model Content

[0004] The purpose of the utility model is to provide a test device for a pulse modulator and a radio frequency power amplifier, in which the control end of the pulse modulation module is connected to the output end of the negative pressure detection module, and pulse modulation is performed to power on the drain voltage port of the radio frequency power amplifier only when the voltage detected by the negative pressure detection module is greater than a preset value, that is, the gate voltage port is confirmed to be powered on, to ensure that the power-on process of the radio frequency power amplifier will first connect the gate voltage port and then the drain voltage port, thereby improving the safety and reliability of the devices in the radio frequency power amplifier.

[0005] In order to solve the above technical problems, the utility model provides a pulse modulator, comprising:

[0006] A negative voltage detection module, the input end of which is respectively connected to the negative voltage output end of the DC power supply and the gate voltage port of the RF power amplifier, and is used to detect the voltage received by the gate voltage port;

[0007] A pulse modulation module, wherein the control end is connected to the output end of the negative pressure detection module, the input end is connected to the positive voltage output end of the DC power supply, and the output end is connected to the drain voltage port of the RF power amplifier, and is used to modulate the DC power supply into a pulse signal when the voltage detected by the negative pressure detection module reaches a preset value.

[0008] Optionally, the pulse modulation module includes:

[0009] A first switch tube, a first end of which is connected to the positive voltage output end of the DC power supply;

[0010] A second switch tube, a first end of which is connected to the second end of the first switch tube and serves as the output end of the pulse modulation module, and a second end of which is grounded;

[0011] A driving module, wherein the power supply end is connected to the first power supply, the ground end is grounded, the input end is connected to the preset level signal, the control end is connected to the output end of the negative pressure detection module, the first output end is connected to the control end of the first switch tube, and the second output end is connected to the control end of the second switch tube; and is used to control the first switch tube and the second switch tube to be alternately turned on when the voltage detected by the negative pressure detection module reaches a preset value, so as to modulate the DC power supply into a pulse signal.

[0012] Optionally, the pulse modulation module further includes:

[0013] A first resistor, a first end of which is connected to the first output end of the driving module, and a second end of which is connected to the control end of the first switch tube;

[0014] A second resistor has a first end connected to the second output end of the driving module, and a second end connected to the control end of the second switch tube.

[0015] Optionally, the pulse modulation module further includes: a first capacitor, a first end of which is connected to the ground end of the driving module, and a second end of which is respectively connected to the power end of the driving module and the first power supply.

[0016] Optionally, the pulse modulation module further includes:

[0017] A unidirectional conduction module, the positive electrode of which is connected to the first power supply;

[0018] A second capacitor has a first end connected to the negative electrode of the unidirectional conduction module and the first voltage end of the driving module, and a second end connected to the second voltage end of the driving module, the second end of the first switch tube, and the first end of the second switch tube.

[0019] Optionally, the pulse modulator further includes:

[0020] A first switching switch, wherein a fixed end is connected to the positive voltage output end of the DC power supply, a first switching end is connected to the input end of the pulse modulation module, and a control end is connected to the output end of the negative pressure detection module;

[0021] A second switching switch, a first switching end connected to the output end of the pulse modulation module, a fixed end connected to the drain voltage port of the RF power amplifier, a second switching end connected to the second switching end of the first switching switch, and a control end connected to the output end of the negative pressure detection module.

[0022] Optionally, the negative pressure detection module includes:

[0023] A first operational amplifier, wherein a non-inverting input terminal is connected to a gate voltage port of the radio frequency power amplifier, and a power supply terminal is connected to a second power supply;

[0024] a first voltage-dividing resistor, a first end of which is respectively connected to the output end of the first operational amplifier and the inverting input end of the first operational amplifier;

[0025] A second operational amplifier, having a non-inverting input terminal grounded and a power supply terminal connected to a third power supply;

[0026] A second voltage-dividing resistor, a first end of which is respectively connected to the inverting input end of the second operational amplifier and the second end of the first voltage-dividing resistor;

[0027] The third operational amplifier, the inverting input end is respectively connected to the second end of the second voltage-dividing resistor and the output end of the second operational amplifier, the non-inverting input end is connected to a preset voltage, the power supply end is connected to the fourth power supply, and the output end serves as the output end of the negative pressure detection module.

[0028] Optionally, the negative pressure detection module further includes: a third resistor, a first end of the third resistor is connected to the inverting input end of the first operational amplifier, and a second end is respectively connected to the output end of the first operational amplifier and the first end of the first voltage divider resistor.

[0029] Optionally, the negative pressure detection module also includes: a fourth resistor, a first end of the fourth resistor is connected to the output end of the third operational amplifier, a second end is connected to the positive power supply end of the third operational amplifier, the positive power supply end of the third operational amplifier is connected to the fourth power supply, and the negative power supply end is grounded.

[0030] In order to solve the above technical problems, the utility model also provides a testing device for an RF power amplifier, including an RF power amplifier and a pulse modulator as described above, wherein the first output end of the pulse modulator is connected to the gate voltage port of the RF power amplifier, and the second output end is connected to the drain voltage port of the RF power amplifier.

[0031] The utility model provides a pulse modulator, including a negative voltage detection module and a pulse modulation module. The input end of the negative voltage detection module is connected in series between the negative voltage output end of a DC power supply and the gate voltage port of a radio frequency power amplifier, and can directly detect the voltage condition of the DC power supply output to the gate voltage port, thereby determining whether the gate voltage port has been powered on. The control end of the pulse modulation module is connected to the output end of the negative voltage detection module, and the detection result of the negative voltage detection module can be determined. Only when the voltage detected by the negative voltage detection module is greater than a preset value, that is, the gate voltage port is confirmed to be powered on, will pulse modulation be performed to power on the drain voltage port of the radio frequency power amplifier. Through the cooperation of the negative voltage detection module and the pulse modulation module, it is ensured that the power-on process of the radio frequency power amplifier will first connect the gate voltage port and then connect the drain voltage port, thereby improving the safety and reliability of the devices in the radio frequency power amplifier.

[0032] The utility model also provides a test device for a radio frequency power amplifier, which has the same beneficial effects as the above-mentioned pulse modulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 A schematic diagram of the structure of a pulse modulator provided by the prior art;

[0035] Figure 2 A schematic diagram of the structure of a pulse modulator provided by the utility model;

[0036] Figure 3 A schematic diagram of the structure of another pulse modulator provided by the utility model;

[0037] Figure 4 A schematic diagram of the structure of a pulse modulation module provided by the utility model;

[0038] Figure 5 A schematic diagram of the structure of a negative pressure detection module provided by the utility model;

[0039] Figure 6 The utility model provides a structural schematic diagram of a test device for a radio frequency power amplifier. DETAILED DESCRIPTION

[0040] The core of the utility model is to provide a test device for a pulse modulator and a radio frequency power amplifier. The control end of the pulse modulation module is connected to the output end of the negative pressure detection module. Only when the voltage detected by the negative pressure detection module is greater than a preset value, that is, the gate voltage port is confirmed to be powered on, will pulse modulation be performed to power on the drain voltage port of the radio frequency power amplifier, ensuring that the power-on process of the radio frequency power amplifier will first connect the gate voltage port and then the drain voltage port, thereby improving the safety and reliability of the devices in the radio frequency power amplifier.

[0041] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0042] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of a pulse modulator provided by the utility model; please refer to Figure 3 , Figure 3 A schematic diagram of the structure of another pulse modulator provided by the utility model; IN+ represents the positive voltage output by the positive voltage output terminal of the DC power supply, IN- represents the negative voltage output by the negative voltage output terminal of the DC power supply, VG represents the voltage received by the gate voltage port of the RF power amplifier, and VD represents the voltage received by the drain voltage port of the RF power amplifier; In order to solve the above technical problems, the utility model provides a pulse modulator, including:

[0043] A negative voltage detection module 1, whose input end is respectively connected to the negative voltage output end of the DC power supply and the gate voltage port of the RF power amplifier, and is used to detect the voltage received by the gate voltage port;

[0044] The pulse modulation module 2 has a control end connected to the output end of the negative pressure detection module 1, an input end connected to the positive voltage output end of the DC power supply, and an output end connected to the drain voltage port of the RF power amplifier, and is used to modulate the DC power supply into a pulse signal when the voltage detected by the negative pressure detection module 1 reaches a preset value.

[0045] It should be noted that when the pulse modulator supplies power to the RF power amplifier, it needs to supply power to the gate voltage port and the drain voltage port of the RF power amplifier respectively. The RF power amplifier will use the amplification effect of power electronic switching tubes such as triodes or MOS tubes (Metal Oxide Semiconductor Field Effect Transistor) to realize the RF amplification process, and these switching tubes need to work in the amplification area to effectively realize the amplification effect. Therefore, the pulse modulator will supply power to the control end and the other end of the switching tube respectively. By providing different sizes of power to the two, it is determined that the switching tube can accurately work in the amplification area. The power supply port for supplying power to the control end of the switching tube is the gate voltage port of the RF power amplifier, and the power supply port for supplying power to the other end of the switching tube except the control end is the drain voltage port of the RF power amplifier.

[0046] Specifically, under normal circumstances, the pulse modulator will provide a negative voltage for the gate voltage port of the RF power amplifier and a positive voltage for the drain voltage port of the RF power amplifier to achieve the amplification effect of the RF power amplifier. In this process, the pulse modulator needs to first use the negative voltage to power on the gate voltage port, and then use the positive voltage to power on the drain voltage port. This can avoid safety issues such as burning of the switching tube. Therefore, the present application sets up a negative voltage detection module 1 connected in series between the negative voltage output end of the DC power supply and the gate voltage port of the RF power amplifier, and detects the power supply process of the DC voltage to the gate voltage port of the RF power amplifier. When the voltage is detected or the detected voltage reaches a certain value, the gate voltage port is powered on. At this time, the pulse modulation module 2 can output a pulse signal obtained based on the positive voltage of the DC voltage. The pulse signal is output to the drain voltage port of the RF power amplifier to power it, ensuring that the drain voltage port is powered on after the gate voltage port is powered on.

[0047] It is not difficult to understand that the basis for judging whether the gate voltage port is successfully powered on will vary due to different actual application situations. Therefore, the specific value of the preset value is not particularly limited in this application. There are many options for the specific circuit structure and implementation method of the negative pressure detection module 1 and the pulse modulation module 2, and the present application does not make special limitations here; the negative voltage output of the DC power supply is directly connected to the gate voltage port of the RF power amplifier through the negative voltage output terminal, and the power supply process of the gate voltage port of the RF power amplifier is directly realized. The positive voltage output of the DC voltage needs to be converted into a pulse signal under the action of the pulse modulation module 2, and then the pulse signal is output to the drain voltage port of the RF power amplifier, and the drain voltage port of the RF power amplifier is powered based on the pulse signal; the specific type and implementation method of the DC power supply are not particularly limited in this application, and it can be implemented by a constant current source or a constant voltage source.

[0048] It should be noted that the RF power amplifier usually includes multiple switch tubes for amplification, and each switch tube requires a power supply process of two ports. In general, the gates of all switch tubes are connected together and powered through the same gate voltage port. At this time, the supply voltage of the DC power supply to the gate voltage port is the sum of the voltages required by the gates of all switch tubes; multiple gate voltage ports can also be set for the RF power amplifier, which are connected one-to-one with the gates of each switch tube, and power can be supplied through multiple pulse modulators at this time; the power supply method of the drain of the switch tube is similar to that of the gate, and this application will not go into details. This application does not make any special restrictions on the specific implementation methods of the gate voltage port and the drain voltage port of the RF power amplifier. The setting of the pulse modulator can also be adjusted according to the setting method of the RF power amplifier in actual applications. The negative pressure detection module 1 is connected in series in the power supply circuit corresponding to the gate of the switch tube to ensure that the pulse modulation module 2 is started after the gate is powered on.

[0049] It is not difficult to understand that the present application realizes the detection of the power-on status of the gate voltage port of the RF power amplifier by adding a negative voltage detection module 1, thereby solving the drain power supply protection problem of the switching tube in the RF power amplifier. The positive voltage of the drain voltage port VD is turned on only after the gate voltage port VG is powered on with negative voltage, thereby reducing the risk of burning the RF power amplifier and protecting the power amplifier chip from being burned.

[0050] Furthermore, in order to facilitate the identification of the detection result of the negative pressure detection module 1, a processor 11 can be added to the pulse modulator. The processor 11 obtains the detection result of the negative pressure detection module 1, and determines whether the gate voltage port of the RF power amplifier is powered on at this time based on the detection result of the negative pressure detection module 1. After the gate voltage port of the RF power amplifier is powered on, the pulse modulation module 2 is controlled to start, and the DC power supply is modulated into a pulse signal. The processor 11 can be implemented using an 8-bit single-chip microcomputer, which saves price and reduces cost.

[0051] It is understandable that a serial port module 12 and a USB (Universal Serial Bus) interface can be further added to the pulse modulator. The pulse modulator can be connected to a remote device such as a PC (Personal computer) through the serial port module 12 to realize the process of remotely controlling the pulse modulator, which is convenient for the construction and testing of the automated test platform; the processor 11 can also further send the current state of the pulse modulator to the remote device through the serial port module 12 and receive PC instructions to realize remote control; the serial port module 12 can be implemented by a serial port communication chip or the like, and the remote device and the pulse modulator can be further directly connected by wire through a USB interface 13; the PC control process can be effectively realized through the serial port module 12 and the USB interface 13, and the processor 11 can realize the synchronization of PC control and its own local control based on this, and the serial port module 12 and the USB interface 13 can provide a good interface for automated testing, facilitate wiring and control, and greatly improve the efficiency of batch testing; modules such as button control can also be set in the pulse modulator itself, and the operator can control the working process of the pulse modulator through buttons.

[0052] Specifically, after the pulse modulator line connection is completed, the processor 11 remains in a standby state after initialization is completed. At the same time, the negative pressure detection module 1 detects the voltage of the gate voltage port in real time, enables the flag of the negative pressure detection module 1 after the gate voltage port is powered on, and disables the flag of the negative pressure detection module 1 when the gate voltage port is not powered on. The processor 11 will first determine in real time whether the serial port module 12 has received valid data and whether the set button has been triggered; if the serial port module 12 receives valid data, the processor 11 queries the preset instruction set to determine the current control instruction. If the button is triggered, the processor 11 queries and calls back the relevant trigger time to determine the current control instruction; then the processor 11 queries the flag of the negative pressure detection module 1. If the flag is enabled, the first switching switch SPDT1, the second switching switch SPDT2 and the pulse modulation module 2 are controlled based on the control instruction to perform corresponding work.

[0053] The utility model provides a pulse modulator, including a negative pressure detection module 1 and a pulse modulation module 2. The input end of the negative pressure detection module 1 is connected in series between the negative pressure output end of a DC power supply and the gate voltage port of a radio frequency power amplifier, and can directly detect the voltage condition of the DC power supply output to the gate voltage port, thereby determining whether the gate voltage port has been powered on. The control end of the pulse modulation module 2 is connected to the output end of the negative pressure detection module 1, and the detection result of the negative pressure detection module 1 can be determined. Only when the voltage detected by the negative pressure detection module 1 is greater than a preset value, that is, the gate voltage port is confirmed to be powered on, will pulse modulation be performed to power on the drain voltage port of the radio frequency power amplifier. Through the cooperation of the negative pressure detection module 1 and the pulse modulation module 2, it is ensured that the gate voltage port is first connected and then the drain voltage port is connected during the power-on process of the radio frequency power amplifier, thereby improving the safety and reliability of the devices in the radio frequency power amplifier.

[0054] Based on the above embodiments:

[0055] Please refer to Figure 4 , Figure 4 A schematic diagram of the structure of a pulse modulation module provided by the utility model; as an optional embodiment, the pulse modulation module 2 includes:

[0056] A first switch tube Q1, a first end of which is connected to a positive voltage output end of a DC power supply;

[0057] A second switch tube Q2, a first end of which is connected to the second end of the first switch tube Q1 and serves as the output end of the pulse modulation module 2, and a second end of which is grounded;

[0058] The driving module 14 has a power supply terminal VCC connected to the first power supply, a ground terminal COM connected to the ground, an input terminal IN connected to a preset level signal, a control terminal SD# connected to the output terminal of the negative pressure detection module 1, a first output terminal HO connected to the control terminal of the first switch tube Q1, and a second output terminal LO connected to the control terminal of the second switch tube Q2; and is used to control the first switch tube Q1 and the second switch tube Q2 to be alternately turned on when the voltage detected by the negative pressure detection module 1 reaches a preset value, so as to modulate the DC power supply into a pulse signal.

[0059] It can be understood that the pulse modulation module 2 can be implemented using a half-bridge circuit, which includes two upper and lower switch tubes. Taking the first switch tube Q1 and the second switch tube Q2 as NMOS tubes as an example, when the gate voltage port is not powered on, the control end EN of the driving module 14 is at a low level. At this time, the first output end HO and the second output end LO of the driving module 14 are also at a low level, and the first switch tube Q1 and the second switch tube Q2 are completely closed to prevent the RF chip from burning; when the gate voltage port is powered on, the control end EN of the driving module 14 is at a high level, and the first output end HO of the driving module 14 changes with the preset level signal TTL_IN connected to the input end, and the second output end LO and the first output end HO are reversed. At this time, the upper and lower switch tubes are alternately turned on to realize the output of the pulse signal, providing a high-power pulse signal to the RF power amplifier. The present application does not make any special restrictions on the specific implementation methods of the first switch tube Q1, the second switch tube Q2 and the driving module 14. The first switch tube Q1 and the second switch tube Q2 can be implemented by NMOS tubes or PMOS tubes, and their working principles are similar to the working process of the above-mentioned NMOS, which will not be repeated in this application. The output of the pulse signal can be achieved by alternating conduction of the two switch tubes; the driving module 14 can be implemented by a driving chip or a driving circuit, and can be set according to the type selection of the first switch tube Q1 and the second switch tube Q2; the present application does not make any special restrictions on the specific value and implementation method of the first power supply, and it can be set and adjusted according to the specific implementation method of the driving module 14.

[0060] Furthermore, considering that the power of the pulse signal required by current RF chips and other RF power amplifier products is relatively large, when selecting the first switch tube Q1 and the second switch tube Q2, both the upper and lower tubes can be high-speed and high-current switch tubes, such as a switch tube with a maximum current of 20A and a maximum voltage of 200V. The use of power switch tubes can also ensure that the delay of the output process of the pulse signal is within 2us, which fully meets the needs of all current RF power amplifier products. The preset level signal can provide timing control for the driving module 14, so that the working process of the pulse modulator can be synchronized with the working process of other modules in the RF chip; the specific type and implementation method of the preset level signal are not particularly limited in this application, and can be used Figure 3 and Figure 4 The TTL signal is shown.

[0061] Specifically, the generation and output process of the pulse signal can be realized by alternately turning on the two switching tubes in the half-bridge circuit. Compared with the pulse modulator that only uses the high-side switch in the prior art, the method provided by the present application has a faster current shutoff capability. The rising edge and falling edge of the pulse signal generated under no-load conditions can be guaranteed to be within 3us, which can effectively reduce the current detection error of the pulse signal. The entire circuit structure is simple and easy to implement. The components used are small in size and low in cost, which is conducive to reducing the size of the entire pulse modulator and saving costs.

[0062] As an optional embodiment, the pulse modulation module 2 further includes:

[0063] A first resistor R1, a first end of which is connected to the first output end of the driving module 14, and a second end of which is connected to the control end of the first switch tube Q1;

[0064] The second resistor R2 has a first end connected to the second output end of the driving module 14 , and a second end connected to the control end of the second switch tube Q2 .

[0065] It is understandable that the first output terminal and the second output terminal of the driving module 14 need to be connected to the control terminals of the two switch tubes respectively. In order to avoid the impact of the control voltage output by the driving module 14 on the control terminal of the switch tube, a first resistor R1 connected to the control terminal of the first switch tube Q1 and a second resistor R2 connected to the control terminal of the second switch tube Q2 can be further added. The first resistor R1 and the second resistor R2 play the role of current limiting and voltage dividing, which can avoid the direct connection between the output terminal of the driving module 14 and the control terminal of the switch tube, and further protect the two switch tubes. The specific type and implementation method of the first resistor R1 and the second resistor R2 are not particularly limited in this application.

[0066] Specifically, the first switch tube Q1 and the second switch tube Q2 can be further protected by further adding the first resistor R1 and the second resistor R2, so as to avoid the voltage output by the driving module 14 being too large and causing damage to the first switch tube Q1 or the second switch tube Q2, thereby protecting the entire pulse modulation module 2; the entire circuit structure is simple and easy to implement, and the components used are small in size and low in cost, which is conducive to reducing the size of the entire pulse modulator and saving costs.

[0067] As an optional embodiment, the pulse modulation module 2 further includes: a first capacitor C1, a first end of which is connected to the ground end of the driving module 14, and a second end of which is respectively connected to the power end of the driving module 14 and the first power supply.

[0068] It is not difficult to understand that in order to improve the accuracy and reliability of the control process of the driving module 14 on the first switch tube Q1 and the second switch tube Q2, a first capacitor C1 connected in parallel can be further added between the power supply terminal and the ground terminal of the driving module 14. The first capacitor C1 can effectively remove the interference of interference factors such as peripheral circuits on the driving module 14 itself, filter out ripples, and avoid the influence of interference signals on the control process of the driving module 14, thereby improving the accuracy and reliability of the control process of the driving module 14 on the first switch tube Q1 and the second switch tube Q2. The specific type and implementation method of the first capacitor C1 are not particularly limited in this application.

[0069] Specifically, the first capacitor C1 can be added to filter out ripples, thereby effectively avoiding the influence of interference signals on the control process of the driving module 14, improving the accuracy and reliability of the control process of the driving module 14 on the first switch tube Q1 and the second switch tube Q2, and ensuring the accurate operation of the pulse modulator; the components used are easy to implement, small in size, and low in cost, which is conducive to reducing the volume of the entire pulse modulator and saving costs.

[0070] As an optional embodiment, the pulse modulation module 2 further includes:

[0071] One-way conducting module D1, the positive electrode of which is connected to the first power supply;

[0072] The second capacitor C2 has a first end connected to the negative electrode of the unidirectional conduction module D1 and the first voltage terminal VB of the driving module 14, and a second end connected to the second voltage terminal Vs of the driving module 14, the second end of the first switch tube Q1 and the first end of the second switch tube Q2.

[0073] It is understandable that a second capacitor C2 can be directly added to the first voltage terminal VB and the second voltage terminal Vs of the driving module 14 itself. The second capacitor C2 is used as a bootstrap capacitor. The characteristic that both ends of the capacitor cannot change suddenly is utilized to ensure that the first switch tube Q1 is fully turned on during the conduction process of the first switch tube Q1 controlled by the driving module 14, so as to avoid the high level of the output pulse signal being unable to accurately drive the RF power amplifier for amplification. Furthermore, a unidirectional conduction module D1 connected in series with the second capacitor C2 can be provided to specify the current direction in the circuit to avoid current backflow. The specific type and implementation method of the second capacitor C2 and the unidirectional conduction module D1 are not particularly limited in this application. The unidirectional conduction module D1 can be implemented using components such as diodes or thyristors.

[0074] Specifically, by adding a second capacitor C2 and a unidirectional conduction module D1, the first switch tube Q1 can be ensured to be fully conducted, further improving the accuracy and reliability of the output pulse signal, and realizing accurate control of the amplifying components inside the RF power amplifier. The entire circuit structure is simple and easy to implement, and the components used are small in size and low in cost, which is conducive to reducing the size of the entire pulse modulator and saving costs.

[0075] As an optional embodiment, the pulse modulator further includes:

[0076] A first switching switch SPDT1, a fixed end connected to the positive voltage output end of the DC power supply, a first switching end connected to the input end of the pulse modulation module 2, and a control end connected to the output end of the negative pressure detection module 1;

[0077] The second switching switch SPDT2 has a first switching end connected to the output end of the pulse modulation module 2, a fixed end connected to the drain voltage port of the RF power amplifier, a second switching end connected to the second switching end of the first switching switch SPDT1, and a control end connected to the output end of the negative pressure detection module 1.

[0078] Considering that the pulse modulator in the prior art can only output a single pulse signal after being connected to the RF power amplifier, if a continuous DC power supply is needed at this time, the operator is required to manually switch the connection line, which poses a safety risk and is time-consuming; therefore, the present embodiment adds a first switching switch SPDT1 and a second switching switch SPDT2, the first switching switch SPDT1 is connected between the positive voltage output end of the DC power supply and the pulse modulation module 2, the second switching switch SPDT2 is set between the pulse modulation module 2 and the RF power amplifier to be tested, so as to realize the pulse signal output by the pulse modulation module and the output of the DC power supply itself. The switching between the continuous DC signals outputted by the first switching switch SPDT1 and the second switching switch SPDT2 also needs to determine whether they can be switched according to the detection result of the negative pressure detection module 1. When no negative pressure is detected at the gate voltage port VG of the RF power amplifier, the default state is the channel corresponding to the pulse modulation module 2, and at this time, both switches in the pulse modulation module 2 are closed to protect the power amplifier chip from being burned; when negative pressure is detected at the gate voltage port VG of the RF power amplifier, the first switching switch SPDT1 and the second switching switch SPDT2 can switch between the pulse signal and the continuous DC signal. The specific type and implementation method of the first switching switch SPDT1 and the second switching switch SPDT2 are not particularly limited in this application. Considering that the pulse signal required by the RF power amplifier is a high-power pulse signal, the first switching switch SPDT1 and the second switching switch SPDT2 can be implemented by single-pole double-throw relays that can pass a large current of 10A.

[0079] Specifically, this embodiment solves the problem that the traditional pulse modulator cannot switch between DC and pulse by adding a first switching switch SPDT1 and a second switching switch SPDT2, effectively realizing the switching between continuous DC signals and pulse signals, and saving the time cost of manual line switching back and forth during the test process; the entire circuit structure is simple and easy to implement, and the components used are small in size and low in cost, which is conducive to reducing the size of the entire pulse modulator and saving costs.

[0080] Please refer to Figure 5 , Figure 5 A schematic diagram of the structure of a negative pressure detection module provided by the utility model; as an optional embodiment, the negative pressure detection module 1 includes:

[0081] A first operational amplifier U1, having a non-inverting input terminal connected to a gate voltage port of the radio frequency power amplifier, and a power supply terminal connected to a second power supply;

[0082] A first voltage-dividing resistor Rf1, a first end of which is respectively connected to the output end of the first operational amplifier U1 and the inverting input end of the first operational amplifier U1;

[0083] A second operational amplifier U2, having a non-inverting input terminal connected to ground and a power supply terminal connected to a third power supply;

[0084] A second voltage-dividing resistor Rf2, a first end of which is respectively connected to the inverting input end of the second operational amplifier U2 and the second end of the first voltage-dividing resistor Rf1;

[0085] The third operational amplifier U3 has an inverting input terminal connected to the second end of the second voltage-dividing resistor Rf2 and the output terminal of the second operational amplifier U2 respectively, a non-inverting input terminal connected to a preset voltage, a power supply terminal connected to a fourth power supply, and an output terminal serving as an output terminal of the negative pressure detection module 1.

[0086] It is not difficult to understand that the negative pressure detection module 1 includes three stages of circuits. The first stage circuit is a common-mode voltage follower implemented by the first operational amplifier U1. The high input impedance characteristic of the integrated operational amplifier is used to reduce the interference of the load detection module on the voltage signal VG of the gate voltage port itself during the detection process. The first operational amplifier U1 is used to enhance the load-carrying capacity of the voltage signal VG, thereby avoiding the possible influence and interference when the gate voltage port is connected to the rear-end load through the first operational amplifier U1, and the voltage signal VG is transmitted to the second stage circuit; the second stage circuit includes a second operational amplifier U2, a first voltage-dividing resistor Rf1 and a second voltage-dividing resistor Rf2, and the second operational amplifier U 2 implements the inverting operational amplifier circuit to amplify the negative voltage VG and convert it into a positive voltage output, and the output voltage Vout after the second-stage circuit is finally amplified is -(Rf2 / Rf1)*VG; the second-stage circuit outputs the amplified output signal to the third-stage circuit, and the third-stage circuit includes a third operational amplifier U3, and one input end of the third operational amplifier U3 is connected to a preset reference voltage, that is, a preset voltage VREF. The third-stage circuit compares the signal obtained from the second-stage circuit with the preset voltage VREF. For example, when the voltage VG at the default gate voltage port is not powered on, a low level is output, and when the voltage VG at the gate voltage port reaches a preset value, that is, when the power-on is completed, a high level is output.

[0087] It should be noted that the specific types and implementation methods of the first operational amplifier U1, the first voltage-dividing resistor Rf1, the second voltage-dividing resistor Rf2, the second operational amplifier U2 and the third operational amplifier U3 are not specifically limited in this application; the negative pressure detection module 1 can also be implemented in other ways, and it is only necessary to effectively implement the comparison process between the voltage VG at the gate voltage port and the preset voltage to determine whether the voltage VG at the gate voltage port is powered on. In general, the power-on range of the voltage VG at the gate voltage port of the RF power amplifier is between (-4)-(-0.5V), so the voltage at the gate voltage port only needs to reach -0.5V to complete the power-on. Taking the amplification factor of the second-stage circuit as 6 times as an example, the reference preset voltage can be set to 3V. The specific values ​​of the preset voltage and the amplification factor of the second-stage circuit can be set according to the actual application requirements, and this application does not make any special restrictions here.

[0088] It is understandable that the present application does not make any special restrictions on the specific values ​​and implementation methods of the second power supply, the third power supply and the fourth power supply. Considering that the driving module 14 also needs the first power supply, there are multiple power supply requirements in the pulse modulator. Therefore, a power conversion module can be further added to the pulse modulator to perform voltage reduction and negative voltage conversion, so as to use the same power supply to convert the first power supply, the second power supply, the third power supply and the fourth power supply. For example, only a single power supply of +12V can be provided externally. The pulse modulator is provided with 12V to 5V\3.3V\-12V parts, 12V can directly power the driving module 14, 5V voltage can power the serial port module 12, 3.3V voltage mainly powers the processor 11 and the third operational amplifier U3 in the negative pressure detection module 1, -12V and +12V cooperate to power the first operational amplifier U1 and the second operational amplifier U2 in the negative pressure detection module 1.

[0089] Specifically, through the setting of the three-stage circuit, the voltage data of the gate voltage port can be effectively and accurately detected, and an intuitive and clear level signal can be directly output through the comparison process to characterize whether the gate voltage port has been powered on. The entire circuit structure is simple and easy to implement. The components used are small in size and low in cost, which is conducive to reducing the size of the entire pulse modulator and saving costs.

[0090] As an optional embodiment, the negative pressure detection module 1 also includes: a third resistor R3, a first end of the third resistor R3 is connected to the inverting input end of the first operational amplifier U1, and a second end is respectively connected to the output end of the first operational amplifier U1 and the first end of the first voltage divider resistor Rf1.

[0091] It is not difficult to understand that a third resistor R3 can be further provided between the output terminal and the inverting input terminal of the first operational amplifier U1 to avoid direct connection between the output terminal and the inverting input terminal of the first operational amplifier U1. The third resistor R3 can play the role of current limiting and voltage dividing, further protecting the first operational amplifier U1, and ensuring the safety and reliability of the first operational amplifier U1 and the entire negative pressure detection module 1. The specific type and implementation method of the third resistor R3 are not particularly limited in this application.

[0092] Specifically, by further adding a third resistor R3 to protect the circuit, the safety and reliability of the first operational amplifier U1 and the entire negative pressure detection module 1 are ensured, the accuracy and reliability of the first-stage circuit are improved, the entire circuit structure is simple and easy to implement, and the components used are small in size and low in cost, which is conducive to reducing the size of the entire pulse modulator and saving costs.

[0093] As an optional embodiment, the negative pressure detection module 1 also includes: a fourth resistor R4, a first end of the fourth resistor R4 is connected to the output end of the third operational amplifier U3, a second end is connected to the positive power supply end of the third operational amplifier U3, the positive power supply end of the third operational amplifier U3 is connected to the fourth power supply, and the negative power supply end is grounded.

[0094] It can be understood that in order to determine the accuracy and reliability of the comparison process and comparison result of the third operational amplifier U3, a fourth resistor R4 can be further set between the positive power supply terminal and the output terminal of the third operational amplifier U3. The fourth resistor R4 serves as a pull-up resistor to ensure the accurate output of the comparison result of the third operational amplifier U3. The specific type and implementation method of the fourth resistor R4 are not particularly limited in this application.

[0095] Specifically, by further adding the fourth resistor R4 to ensure the accuracy and reliability of the comparison result of the third operational amplifier U3, the accuracy of the working process of the pulse modulation module 2 is improved. The entire circuit structure is simple and easy to implement. The components used are small in size and low in cost, which is conducive to reducing the size of the entire pulse modulator and saving costs.

[0096] Please refer to Figure 6 , Figure 6 A schematic diagram of the structure of a test device for a radio frequency power amplifier provided by the utility model. To solve the above technical problems, the utility model also provides a test device for a radio frequency power amplifier, comprising a radio frequency power amplifier 22 and a pulse modulator 21 as described above, wherein a first output terminal of the pulse modulator 21 is connected to a gate voltage port of the radio frequency power amplifier 22, and a second output terminal of the pulse modulator 21 is connected to a drain voltage port of the radio frequency power amplifier 22.

[0097] For an introduction to a test device for a radio frequency power amplifier provided by the present invention, please refer to the above-mentioned embodiment of the pulse modulator, and the present invention will not be described in detail here.

[0098] 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.

[0099] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A pulse modulator, characterized in that: include: A negative voltage detection module, the input end of which is respectively connected to the negative voltage output end of the DC power supply and the gate voltage port of the RF power amplifier, and is used to detect the voltage received by the gate voltage port; A pulse modulation module, wherein the control end is connected to the output end of the negative pressure detection module, the input end is connected to the positive voltage output end of the DC power supply, and the output end is connected to the drain voltage port of the RF power amplifier, and is used to modulate the DC power supply into a pulse signal when the voltage detected by the negative pressure detection module reaches a preset value.

2. The pulse modulator according to claim 1, characterized in that The pulse modulation module comprises: A first switch tube, a first end of which is connected to the positive voltage output end of the DC power supply; A second switch tube, a first end of which is connected to the second end of the first switch tube and serves as the output end of the pulse modulation module, and a second end of which is grounded; A driving module, wherein the power supply end is connected to the first power supply, the ground end is grounded, the input end is connected to the preset level signal, the control end is connected to the output end of the negative pressure detection module, the first output end is connected to the control end of the first switch tube, and the second output end is connected to the control end of the second switch tube; and is used to control the first switch tube and the second switch tube to be alternately turned on when the voltage detected by the negative pressure detection module reaches a preset value, so as to modulate the DC power supply into a pulse signal.

3. The pulse modulator according to claim 2, characterized in that The pulse modulation module also includes: A first resistor, a first end of which is connected to the first output end of the driving module, and a second end of which is connected to the control end of the first switch tube; A second resistor has a first end connected to the second output end of the driving module, and a second end connected to the control end of the second switch tube.

4. The pulse modulator according to claim 3, characterized in that The pulse modulation module further includes: a first capacitor, a first end of which is connected to the ground end of the driving module, and a second end of which is respectively connected to the power end of the driving module and the first power supply.

5. The pulse modulator according to claim 4, characterized in that The pulse modulation module also includes: A unidirectional conduction module, the positive electrode of which is connected to the first power supply; A second capacitor has a first end connected to the negative electrode of the unidirectional conduction module and the first voltage end of the driving module, and a second end connected to the second voltage end of the driving module, the second end of the first switch tube, and the first end of the second switch tube.

6. The pulse modulator according to claim 1, characterized in that The pulse modulator also includes: A first switching switch, wherein a fixed end is connected to the positive voltage output end of the DC power supply, a first switching end is connected to the input end of the pulse modulation module, and a control end is connected to the output end of the negative pressure detection module; A second switching switch, a first switching end connected to the output end of the pulse modulation module, a fixed end connected to the drain voltage port of the RF power amplifier, a second switching end connected to the second switching end of the first switching switch, and a control end connected to the output end of the negative pressure detection module.

7. The pulse modulator according to any one of claims 1 to 6, characterized in that: The negative pressure detection module comprises: A first operational amplifier, wherein a non-inverting input terminal is connected to a gate voltage port of the radio frequency power amplifier, and a power supply terminal is connected to a second power supply; a first voltage-dividing resistor, a first end of which is respectively connected to the output end of the first operational amplifier and the inverting input end of the first operational amplifier; A second operational amplifier, having a non-inverting input terminal grounded and a power supply terminal connected to a third power supply; A second voltage-dividing resistor, a first end of which is respectively connected to the inverting input end of the second operational amplifier and the second end of the first voltage-dividing resistor; The third operational amplifier, the inverting input end is respectively connected to the second end of the second voltage-dividing resistor and the output end of the second operational amplifier, the non-inverting input end is connected to a preset voltage, the power supply end is connected to the fourth power supply, and the output end serves as the output end of the negative pressure detection module.

8. The pulse modulator according to claim 7, characterized in that The negative pressure detection module also includes: a third resistor, a first end of the third resistor is connected to the inverting input end of the first operational amplifier, and a second end of the third resistor is respectively connected to the output end of the first operational amplifier and the first end of the first voltage divider resistor.

9. The pulse modulator according to claim 8, characterized in that The negative pressure detection module also includes: a fourth resistor, a first end of the fourth resistor is connected to the output end of the third operational amplifier, a second end is connected to the positive power supply end of the third operational amplifier, the positive power supply end of the third operational amplifier is connected to the fourth power supply, and the negative power supply end is grounded.

10. A test device for a radio frequency power amplifier, characterized in that: It comprises a radio frequency power amplifier and a pulse modulator as described in any one of claims 1 to 9, wherein the first output terminal of the pulse modulator is connected to the gate voltage port of the radio frequency power amplifier, and the second output terminal is connected to the drain voltage port of the radio frequency power amplifier.

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