A program-controlled attenuator

Abstract

The invention relates to the technical field of communication calibration measurement and automated testing, and discloses a programmable attenuator, wherein a power input terminal is connected to a working power supply; a voltage conversion circuit converts the voltage of the working power supply to an attenuation working voltage within a preset range; a switch driving circuit is connected to a driving signal, and when an attenuation gating circuit is connected to the attenuation working voltage, the attenuation gating circuit conducts a first attenuation path or a second attenuation path according to the driving signal. The invention adds a voltage conversion circuit before the attenuation gating circuit, so that as long as the voltage range of the working power input is within the range processed by the voltage conversion circuit, voltage processing can be performed, so that the attenuation working voltage provided to the attenuation gating circuit can be maintained within the preset range, thereby solving the technical problem that the attenuator is easily burned due to the wrong working voltage.

Description

Technical Field

[0001] The embodiment of the invention relates to the technical field of communication calibration measurement and automated testing, and in particular to a programmable attenuator. Background Art

[0002] The programmable attenuator has the function of absorbing the transmission signal power. It is mainly used to control the signal level amplitude entering the system, control the output signal power of the system, adjust the matching between the signal source and the load, and can also be used to simulate the loss of the signal transmission path in the communication system. It has a wide range of applications in automatic test systems, measurement and detection, test instruments, and modern communication test systems.

[0003] The workpiece voltage of the circuit where the programmable attenuator is located cannot exceed the rated working voltage of the programmable attenuator, otherwise the programmable attenuator will easily burn out, which will limit the usage scenarios. Applying the wrong voltage may cause damage to the programmable attenuator, and a single test environment may require purchasing programmable attenuators with different suffixes, which brings many inconveniences to the testing and management of attenuator manufacturers. Summary of the invention

[0004] In view of the above problems, an embodiment of the present invention provides a programmable attenuator, which is used to solve the technical problem in the prior art that applying a wrong working voltage easily causes the attenuator to burn out.

[0005] According to one aspect of an embodiment of the present invention, a programmable attenuator is provided, the programmable attenuator comprising:

[0006] Power input terminal, used to connect to the working power supply;

[0007] A voltage conversion circuit, connected to the power input terminal and used for converting the voltage of the working power supply to an attenuated working voltage within a preset range;

[0008] A switch driving circuit, connected to the voltage conversion circuit, for receiving a driving signal;

[0009] as well as,

[0010] The attenuation gating circuit is connected to the switch driving circuit and the voltage conversion circuit respectively. The attenuation gating circuit has a first attenuation path and a second attenuation path. When the attenuation working voltage is connected, the first attenuation path or the second attenuation path is turned on according to the driving signal.

[0011] In an optional manner, the power input end includes a positive power input end and a negative power input end, and the voltage conversion circuit includes a first inductor, a first capacitor, a first switch, a second inductor, a first diode, a second capacitor, a third capacitor and a first resistor. The first end of the first inductor is respectively connected to the positive power input end and the first end of the first capacitor, and its connection node is connected to a positive power supply. The second end of the first inductor, the first end of the first switch and the first end of the second capacitor are interconnected; the controlled end of the first switch is connected to a power control signal, the second end of the second capacitor, the first end of the second inductor and the anode of the first diode are interconnected; the cathode of the first diode, the first end of the third capacitor and the first end of the first resistor are interconnected, and when the controlled end of the first switch is connected to the power control signal, the connection node outputs the attenuated working voltage within a preset range, and the second end of the third capacitor, the second end of the first resistor, the second end of the second inductor, the second end of the first switch, the second end of the first capacitor and the negative power input end are grounded.

[0012] In an optional manner, the switch driving circuit includes a first inverter, a first operation gate, a second operation gate, a first triode, a second triode, a second diode and a third diode, the input end of the first inverter is connected to the first input end of the first operation gate for accessing the driving signal, the output end of the first inverter is connected to the first input end of the second operation gate; the second input end of the first operation gate is connected to the second input end of the second operation gate for accessing a logic level in a preset range; the output end of the first operation gate is connected to the first end of the first triode, the second end of the first triode is connected to the cathode of the second diode, and the connection node thereof outputs the processed driving signal, the third end of the first triode, the third end of the second triode, the anode of the second diode, and the anode of the third diode are all grounded; the output end of the second operation gate is connected to the first end of the third triode; the second end of the third triode is connected to the cathode of the third diode, and the connection node thereof outputs the processed driving signal.

[0013] In an optional manner, the attenuation gating circuit includes a relay circuit and an attenuation circuit, the relay circuit includes a first controlled end, a second controlled end, a power input end, a power output end and a magnetic end, the attenuation circuit includes a first controlled end, a second controlled end, a radio frequency input end and a radio frequency output end, the first controlled end of the relay circuit is connected to the drive signal, the second controlled end of the relay circuit is connected to the processed drive signal, the power input end of the relay circuit is connected to the attenuation working voltage, the power output end of the relay circuit is grounded, the magnetic end of the relay circuit and the first controlled end and the second controlled end of the attenuation circuit can be magnetically arranged, the radio frequency input end of the attenuation circuit obtains the radio frequency signal to be attenuated, and the radio frequency output end of the attenuation circuit outputs the processed radio frequency signal to be attenuated;

[0014] The relay circuit is provided with a first relay path and a second relay path, which are used to control the first relay path or the second relay path to be turned on according to the driving signal;

[0015] The attenuation circuit is provided with the first attenuation path and the second attenuation path, and controls the corresponding attenuation path to be turned on according to the conduction states of the first relay path and the second relay path.

[0016] In an optional manner, the relay circuit includes a fourth diode, a fifth diode, a magnetic holding switch, a first coil and a second coil, the magnetic holding switch includes a controlled end, a first contact, a second contact, a third contact and a fourth contact, the anode of the fourth diode and the anode of the fifth diode are connected, and the connection node is the power input end of the relay circuit, the controlled end of the magnetic holding switch is respectively connected to the cathode of the fourth diode and the cathode of the fifth diode, and connected to the drive signal; the first coil has a first end point, a second end point and a middle end point, the first end point of the first coil is connected to the first end point of the second coil, and the middle end point of the first coil is connected to the attenuation working voltage;

[0017] When the driving signal is at a high level, the first contact of the magnetic holding switch is suspended, the second contact of the magnetic holding switch is grounded, the third contact of the magnetic holding switch is connected to the second end of the first coil, and the fourth contact of the magnetic holding switch is suspended;

[0018] When the driving signal is at a low level, the first contact of the magnetic holding switch is grounded, the second contact of the magnetic holding switch is suspended, the fourth contact of the magnetic holding switch is connected to the second end of the first coil, and the third contact of the magnetic holding switch is suspended.

[0019] In an optional manner, the attenuation circuit includes a first magnetic switch, a second magnetic switch, a second resistor, a third resistor and a fourth resistor, the first magnetic switch includes a controlled end, a first connection end, a second connection end and a third connection end, the second magnetic switch includes a controlled end, a first connection end, a second connection end and a third connection end, the controlled end of the first magnetic switch and the controlled end of the second magnetic switch can be magnetically arranged with the second coil, the first connection end of the first magnetic switch is connected to the first connection end of the second magnetic switch, the second connection end of the first magnetic switch is connected to the first end of the second resistor, and the third connection end of the first magnetic switch is connected to the RF signal to be attenuated; the second end of the second resistor, the first end of the third resistor and the first end of the fourth resistor are interconnected; the first end of the third resistor is connected to the second end of the second magnetic switch; the second end of the fourth resistor is grounded; the third connection end of the second magnetic switch outputs the processed RF signal to be attenuated.

[0020] In an optional manner, the programmable attenuator further comprises a level indication circuit, an input end of the level indication circuit is connected to the processed driving signal, and an output end of the level indication circuit outputs a level indication signal;

[0021] The level indication circuit is used to detect the processed driving signal and output the processed signal to indicate the level of the driving signal.

[0022] In an optional manner, the level indication circuit includes a second inverter, a fifth resistor and a sixth resistor, the first end of the fifth resistor is the input end of the level indication circuit, the second end of the fifth resistor is respectively connected to the first end of the sixth resistor and the input end of the second inverter, and the second end of the sixth resistor is grounded; the output end of the second inverter is the output end of the level indication circuit.

[0023] In an optional manner, the programmable attenuator further includes a light-emitting indication circuit, an input end of the light-emitting indication circuit is connected to the processed driving signal, and a power supply end of the light-emitting indication circuit is connected to a light-emitting working power supply;

[0024] The light-emitting indicating circuit is used to indicate the working status of the relay circuit and the attenuation circuit.

[0025] In an optional manner, the light-emitting indication circuit includes a light-emitting diode, a third inverter, a seventh resistor, an eighth resistor and a ninth resistor, the first end of the seventh resistor is the input end of the light-emitting indication circuit, the second end of the seventh resistor is respectively connected to the first end of the eighth resistor and the input end of the third inverter, and the second end of the eighth resistor is grounded; the output end of the third inverter is connected to the first end of the ninth resistor, and the second end of the ninth resistor is connected to the cathode of the light-emitting diode; the anode of the light-emitting diode is the power supply end of the light-emitting indication circuit.

[0026] The present invention adds a voltage conversion circuit before the attenuation gating circuit, so that as long as the voltage range of the working power input is within the range processed by the voltage conversion circuit, voltage processing can be performed, so that the attenuation working voltage provided to the attenuation gating circuit can be maintained within a preset range, thereby solving the technical problem that the attenuator is easily burned out due to the wrong working voltage.

[0027] In addition, the present invention also sets a switch driving circuit and an attenuation selection circuit, so that the attenuation path can be selected according to the driving signal within a relatively wide voltage range of the working power supply, thereby realizing the selection of the attenuation effect. While expanding the voltage range of the electrical working power supply for the attenuation operation, it also expands the selection of different attenuation effects, thereby expanding the scope of use of the programmable attenuator and improving the flexibility of the use of the programmable attenuator.

[0028] The above description is only an overview of the technical solution of the embodiment of the present invention. In order to more clearly understand the technical means of the embodiment of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings:

[0030] Figure 1 A schematic diagram of a module of a programmable attenuator provided by the present invention is shown;

[0031] Figure 2 A circuit diagram of a first embodiment of a programmable attenuator provided by the present invention is shown;

[0032] Figure 3 A circuit diagram of a relay circuit and an attenuation circuit in a programmable attenuator provided by the present invention is shown;

[0033] Figure 4A circuit diagram of a voltage conversion circuit in a programmable attenuator provided by the present invention is shown;

[0034] Figure 5 The schematic diagram of the structure of the programmable attenuator provided by the present invention is shown. DETAILED DESCRIPTION

[0035] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0036] The following is an analysis of the programmable attenuator solution in the prior art in combination with related technologies.

[0037] The three main parts of the programmable attenuator include: 1. RF component 2. Relay component 3. Control circuit

[0038] a. The RF component is mainly composed of coaxial connectors, transmission lines, and attenuation cards, which are mainly used to realize the transmission and attenuation of RF signals;

[0039] b. The relay assembly is mainly composed of a magnetic latching relay and a push rod assembly. The magnetic latching relay can realize a bidirectional magnetic latching function and maintain the power-off state;

[0040] c. The control circuit is mainly composed of interface circuit and logic control circuit to realize interface conversion and control of relays in different paths.

[0041] Since the control coil in the components of the magnetic latching relay has a small withstand voltage range and inconsistent current carrying capacity, in order to achieve maximum economic benefits and a smaller size, the rated working voltage of the relay is the most important technical parameter of the relay. When using a relay, the working voltage of the circuit (i.e. the circuit where the relay coil is located) should be considered first. The rated working voltage of the relay should be equal to the working voltage of the circuit. The programmable attenuators on the market generally have a narrow control voltage range, so programmable attenuators with different voltage controls are produced for different control voltages.

[0042] The present application provides a programmable attenuator, which can add a voltage conversion circuit before the attenuation gating circuit, so that the attenuation operating voltage provided to the attenuation gating circuit can be maintained within a preset range, thereby solving the technical problem that adding the wrong operating voltage can easily cause the attenuator to burn out.

[0043] Figure 1The module diagram of the first embodiment of the programmable attenuator of the present invention is shown, and the programmable attenuator includes a power input terminal V2, a voltage conversion circuit 20, a switch driving circuit 30 and an attenuation gating circuit 40. The voltage conversion circuit 20 is connected to the power input terminal V2, and the switch driving circuit 30 is connected to the voltage conversion circuit 20. The attenuation gating circuit 40 is respectively connected to the switch driving circuit 30 and the voltage conversion circuit 20. The attenuation gating circuit 40 has a first attenuation path and a second attenuation path.

[0044] Among them, the power input terminal V2 is used to connect to the working power supply, the voltage conversion circuit 20 converts the voltage of the working power supply to an attenuated working voltage within a preset range, the switch drive circuit 30 connects to the drive signal, and the attenuation selection circuit 40, when connected to the attenuation working voltage, turns on the first attenuation path or the second attenuation path according to the drive signal.

[0045] The present invention adds a voltage conversion circuit 20 before the attenuation selection circuit 40, so that the voltage range of the working power input can be processed as long as it is within the range processed by the voltage conversion circuit 20, so that the attenuation working voltage provided to the attenuation selection circuit 40 can be maintained within the preset range, thereby solving the technical problem that the attenuator is easily burned out due to the wrong working voltage.

[0046] In addition, the present invention also sets a switch driving circuit 30 and an attenuation selection circuit 40, so that the attenuation path can be selected according to the driving signal within a relatively wide voltage range of the working power supply, thereby realizing the selection of the attenuation effect. While expanding the voltage range of the electrical working power supply for the attenuation operation, it also expands the selection of different attenuation effects, thereby expanding the scope of use of the programmable attenuator and improving the flexibility of the use of the programmable attenuator.

[0047] In an alternative approach, refer to Figure 4As shown, the power input terminal V2 includes a positive power input terminal and a negative power input terminal, and the voltage conversion circuit 20 includes a first inductor L1, a first capacitor C1, a first switch Q1, a second inductor L2, a first diode D1, a second capacitor C2, a third capacitor C3 and a first resistor R1. The first end of the first inductor L1 is connected to the positive power input terminal and the first end of the first capacitor C1 respectively, and its connection node is connected to the positive power supply. The second end of the first inductor L1, the first end of the first switch Q1 and the first end of the second capacitor C2 are interconnected; the controlled end of the first switch Q1 is connected to the power control signal, the second end of the second capacitor C2, the first end of the second inductor L2 and the anode of the first diode D1 are interconnected; the cathode of the first diode D1, the first end of the third capacitor C3 and the first end of the first resistor R1 are interconnected, and when the controlled end of the first switch Q1 is connected to the power control signal, the connection node outputs an attenuated working voltage within a preset range, and the second end of the third capacitor C3, the second end of the first resistor R1, the second end of the second inductor L2, the second end of the first switch Q1, the second end of the first capacitor C1 and the negative power input terminal are grounded.

[0048] Among them, when the power control signal SW is at a high level, the first switch Q1 is turned on, and at this time, the current loop flows from the power supply through the first inductor L1 for energy storage and through the first switch Q1 to form a first loop. The current in the first inductor L1 in the first loop rises linearly to store energy. Since the current of the second capacitor C2 in the second loop was previously charged to the power input power supply, the energy conversion of the second inductor L2 is performed at this time, and further, a place for the second capacitor C2 to release energy is provided to keep the average value of the voltage stable within a certain range. At this time, the first diode D1 is cut off, so it can only continue to provide current to the load through the third capacitor C3 at the load end.

[0049] When the power control signal SW is at a low level, the first switch Q1 is turned off. Since the current direction in the two inductors does not change suddenly due to the inductance characteristics, the voltage polarity at both ends of the inductors will change so that the current continues to flow. At this time, two current loops will be formed. The first loop is from the power supply through the first inductor L1 with energy storage, then through the second capacitor C2, then through the first diode D1, and finally through the load. This load is formed by the first resistor R1 in parallel to form a loop. The second loop is discharged by the second inductor L2 with energy storage, passes through the first diode D1, and then passes through the load to form a loop. At this stage, the power supply voltage and the first load R1 are both supplied with power, and the second capacitor C2 is also charged.

[0050] In this way, the power control signal SW controls the first switch Q1 to work in a switching manner, and the load always has a stable voltage output. The third decoupling capacitor C3 is added in the later stage. The high-frequency impedance characteristics of the decoupling capacitor can effectively bypass the interference signal, thereby reducing the interference signal caused by the switching frequency switching. The stable power output of the later stage ensures the normal operation of the programmable attenuator.

[0051] In an alternative approach, refer to Figure 2 As shown, the switch driving circuit 30 includes a first inverter U1, a first operation gate U2, a second operation gate U3, a first transistor Q1, a second transistor Q2, a second diode D2 and a third diode D3. The input end of the first inverter U1 is connected to the first input end of the first operation gate U2 for receiving a driving signal. The output end of the first inverter U1 is connected to the first input end of the second operation gate U3; the second input end of the first operation gate U2 is connected to the second input end of the second operation gate U3 for receiving a logic level in a preset range; the output end of the first operation gate U2 is connected to the first end of the first transistor Q1, the second end of the first transistor Q1 is connected to the cathode of the second diode D2, and the connection node thereof outputs the processed driving signal. The third end of the first transistor Q1, the third end of the second transistor Q2, the anode of the second diode D2 and the anode of the third diode D3 are all grounded; the output end of the second operation gate U3 is connected to the first end of the second transistor; the second end of the second transistor is connected to the cathode of the third diode D3, and the connection node thereof outputs the processed driving signal.

[0052] The first operation gate U2 and the second operation gate U3 are AND gates. The driving signal is reversed through the first inverter U1. The normal driving signal and the reversed driving signal are respectively input into the first operation gate U2 and the second operation gate U3, and AND operation is performed with the logic level in the preset range, so that the driving signal in the first direction is output through the first transistor Q1 and the second diode D2; the reverse driving signal is output through the second transistor Q2 and the third diode D3, thereby forming a flow path for the driving signal. It is ensured that the driving signal can form a voltage difference on both sides of the relay circuit to form a path.

[0053] In an alternative approach, refer to Figure 2 as well as Figure 3As shown, the attenuation gating circuit 40 includes a relay circuit 401 and an attenuation circuit 402. The relay circuit 401 includes a first controlled end, a second controlled end, a power input end V2, a power output end and a magnetic end. The attenuation circuit 402 includes a first controlled end, a second controlled end, a radio frequency input end and a radio frequency output end. The first controlled end of the relay circuit 401 is connected to a driving signal, the second controlled end of the relay circuit 401 is connected to a processed driving signal, the power input end V2 of the relay circuit 401 is connected to an attenuation working voltage, the power output end of the relay circuit 401 is grounded, the magnetic end of the relay circuit 401 and the first controlled end and the second controlled end of the attenuation circuit 402 can be magnetically arranged, the radio frequency input end of the attenuation circuit 402 obtains the radio frequency signal to be attenuated, and the radio frequency output end of the attenuation circuit 402 outputs the processed radio frequency signal to be attenuated.

[0054] The relay circuit 401 is provided with a first relay path and a second relay path, and the relay circuit 401 controls the first relay path or the second relay path to be turned on according to the driving signal. The attenuation circuit 402 is provided with a first attenuation path and a second attenuation path, and the attenuation circuit 402 controls the corresponding attenuation path to be turned on according to the conduction state of the first relay path and the second relay path.

[0055] Through the above configuration, the switching of the attenuation circuit 402 can be controlled by controlling the switching of the path of the relay circuit 401, so that the attenuation path can be selected according to the demand, thereby expanding the application range of the attenuator.

[0056] It should be noted that multiple attenuation paths may also be set, and it is only necessary to modify the number of relay circuits 401 and drive signals accordingly.

[0057] In addition, the first operation gate U2, the second operation gate U3, the first transistor Q1 and the second transistor Q2 are integrated on one chip.

[0058] In an alternative approach, refer to Figure 2 as well as Figure 3 As shown, the relay circuit 401 includes a fourth diode D4, a fifth diode D5, a magnetic holding switch S, a first coil a1 and a second coil a2, the magnetic holding switch S includes a controlled end, a first contact 1, a second contact 2, a third contact 3 and a fourth contact 4, the anode of the fourth diode D4 and the anode of the fifth diode D5 are connected, and the connection node is the power input terminal V2 of the relay circuit 401, the controlled end of the magnetic holding switch S is respectively connected to the cathode of the fourth diode D4 and the cathode of the fifth diode D5, and connected to the driving signal; the first coil a1 has a first end point, a second end point and a middle end point, the first end point of the first coil a1 is connected to the first end point of the second coil a2, and the middle end point of the first coil a1 is connected to the attenuated working voltage.

[0059] Wherein, when the driving signal is at a high level, the first contact 1 of the magnetic holding switch S is suspended, the second contact 2 of the magnetic holding switch S is grounded, the third contact 3 of the magnetic holding switch S is connected to the second end of the first coil a1, and the fourth contact 4 of the magnetic holding switch S is suspended. When the driving signal is at a low level, the first contact 1 of the magnetic holding switch S is grounded, the second contact 2 of the magnetic holding switch S is suspended, the fourth contact 4 of the magnetic holding switch S is connected to the second end of the first coil a1, and the third contact 3 of the magnetic holding switch S is suspended.

[0060] Figure 3 Schematic diagram of relay circuit 401 and attenuator circuit, in which driving signal V1 is the external control signal of the relay circuit, a1 and a2 are switch-controlled attenuation plate control coils (the first coil a1 is the attenuation plate control coil, and the second coil a2 is the dashed line in the figure is the straight-through line control coil), s is the magnetic latching switch S inside the relay circuit, in is the RF input port, out is the RF output port, the second attenuation path Att is the internal attenuation circuit 402, and the first attenuation path Thru is the straight-through path. When driving signal V1 is high level (>1.2Vvpp), the internal magnetic latching switch S of the control coil of attenuation circuit 402 is activated, the electric contact is closed, and part of attenuation circuit 402 begins to have current passing through, and at the same time, the internal magnetic latching switch S of another group of control coils (straight-through circuit) is disconnected and grounded, and at this time, attenuation circuit 402 switches to attenuation state. When driving signal V1 is low level (<0.3Vvpp), the attenuator will switch to the straight-through path (0dB insertion loss).

[0061] It should be noted that the through circuit at this time may also be set as a circuit with a certain attenuation as required.

[0062] In the above circuit, the middle end point of the first coil a1 is connected to the attenuated working voltage so that the connected voltage is within a preset range, while the voltage of the working power supply connected to the voltage conversion circuit 20 is not limited, thereby expanding the voltage range of the working voltage of the control coil.

[0063] In an alternative approach, refer to Figure 2 as well as Figure 3As shown, the attenuation circuit 402 includes a first magnetic switch QS1, a second magnetic switch QS2, a second resistor R2, a third resistor R3 and a fourth resistor R4, the first magnetic switch QS1 includes a controlled end, a first connection end, a second connection end and a third connection end, the second magnetic switch QS2 includes a controlled end, a first connection end, a second connection end and a third connection end, the controlled end of the first magnetic switch QS1 and the controlled end of the second magnetic switch QS2 can be magnetically arranged with the second coil a2, and the first connection end of the first magnetic switch QS1 is connected to the second coil a2. The first connection end of the first magnetic switch QS2 is connected, the second connection end of the first magnetic switch QS1 is connected to the first end of the second resistor R2, and the third connection end of the first magnetic switch QS1 is connected to the RF signal to be attenuated; the second end of the second resistor R2, the first end of the third resistor R3 and the first end of the fourth resistor R4 are interconnected; the first end of the third resistor R3 is connected to the second end of the second magnetic switch QS2; the second end of the fourth resistor R4 is grounded; the third connection end of the second magnetic switch QS2 outputs the processed RF signal to be attenuated.

[0064] Figure 4 The schematic diagram of the attenuator internal control driving circuit is shown in FIG. 1 , where V2 is the power supply voltage of the relay circuit control coil. The present invention connects a voltage conversion circuit 20 (such as Figure 5 ), keep V2 at 3.7V±0.1V, and Figure 3 The control coils a1 and a2 are replaced with 5V (3V-7V) magnetic latching relay coils. The voltage conversion circuit 20 can withstand voltages of 3V-50V. When the external power supply voltage fluctuates from 3V to 50V, the V2 voltage remains within the range of 3.7V±0.1V; the overall mass of the attenuator only increases by 3g, which is within the mass error requirement of the programmable attenuator (±3%).

[0065] This method solves the technical problem that different external power supply voltages require the attenuator model to be replaced to adapt to different external power supply voltages. It reduces the test workflow during testing and greatly reduces the risk of burning the attenuator due to adding the wrong voltage. In addition, after reducing the V2 voltage, the power consumption of the attenuator is reduced by about 30%. At the same time, for attenuator manufacturers, the product models are reduced, which helps to reduce the management cost of the product. The above improvements have greatly improved the performance and practicality of existing programmable attenuators.

[0066] In an optional manner, the programmable attenuator further includes a level indicating circuit 50, referring to Figure 2 As shown, the input end of the level indicating circuit 50 is connected to the processed driving signal, and the output end of the level indicating circuit 50 outputs the level indicating signal.

[0067] The level indication circuit 50 detects the processed driving signal and outputs it to indicate the level of the driving signal. In the above manner, the collected driving signal can be output to a display instrument or a processor for processing, or can be output for storage, thereby recording the change of the driving signal.

[0068] In an optional manner, the level indication circuit 50 includes a second inverter U4, a fifth resistor R5 and a sixth resistor R6, the first end of the fifth resistor R5 is the input end of the level indication circuit 50, the second end of the fifth resistor R5 is respectively connected to the first end of the sixth resistor R6 and the input end of the second inverter U4, and the second end of the sixth resistor R6 is grounded; the output end of the second inverter U4 is the output end of the level indication circuit 50.

[0069] Among them, by setting the second inverter U4, the positive and negative of the output drive signal can be adjusted to make it consistent with the drive input end. In addition, setting the fifth resistor R5 and the sixth resistor R6 can reduce the voltage and shunt the drive signal to avoid the collected signal being too large.

[0070] In an alternative approach, refer to Figure 2 As shown, the programmable attenuator also includes a light-emitting indication circuit 60, the input end of the light-emitting indication circuit 60 is connected to the processed driving signal, and the power supply end of the light-emitting indication circuit 60 is connected to the light-emitting working power supply.

[0071] Among them, the light indicating circuit 60 indicates the working status of the relay circuit 401 and the attenuation circuit 402. Since there is a linkage relationship between the driving signal, the relay circuit 401 and the attenuation circuit 402, the working status of the relay circuit 401 and the attenuation circuit 402 can be indicated by collecting the driving signal without directly acquiring the working status of the relay circuit 401 and the attenuation circuit 402.

[0072] In an optional manner, the light-emitting indication circuit 60 includes a light-emitting diode UD1, a third inverter U5, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9, wherein the first end of the seventh resistor R7 is the input end of the light-emitting indication circuit 60, the second end of the seventh resistor R7 is respectively connected to the first end of the eighth resistor R8 and the input end of the third inverter U5, and the second end of the eighth resistor R8 is grounded; the output end of the third inverter U5 is connected to the first end of the ninth resistor R9, and the second end of the ninth resistor R9 is connected to the cathode of the light-emitting diode UD1; the anode of the light-emitting diode UD1 is the power supply end of the light-emitting indication circuit 60.

[0073] The light emitting diode UD1 is lit when the driving signal is at a high level, indicating that the second attenuation path is turned on.

[0074] The following combination Figure 1-Figure 5 The working process of the present invention is described:

[0075] Figure 4 The schematic diagram of the attenuator internal control driving circuit is shown in FIG. 1 , where V2 is the power supply voltage of the relay circuit control coil. The present invention connects a voltage conversion circuit 20 (such as Figure 5 ), keep V2 at 3.7V±0.1V, and Figure 3 The control coils a1 and a2 are replaced with 5V (3V~7V) magnetic latching relay coils. The voltage conversion circuit 20 can withstand voltages of 3V~50V. When the external power supply voltage fluctuates from 3V~50V, the V2 voltage remains within the range of 3.7V±0.1V; the overall mass of the attenuator only increases by 3g, which is within the mass error requirement of the programmable attenuator (±3%).

[0076] The specific working principle of the voltage conversion circuit 20 is as follows:

[0077] When the power control signal SW is high, the first switch Q1 is turned on. At this time, the current loop flows from the power supply through the energy storage inductor L1 and the switch device Q1 to form the first loop. The current in the inductor in the first loop rises linearly to store energy. The current in the second loop C2 is previously charged to the power input power supply. At this time, through the L2 energy conversion, it also provides a place for C2 to release energy, so as to keep the average voltage stable within a certain range. At this time, the diode D1 is cut off, so it can only continue to provide current to the load through the capacitor C3 at the load end.

[0078] When the power control signal SW is low, the first switch Q1 is turned off. Since the current direction in the two inductors does not change suddenly due to the inductance characteristics, the voltage polarity at both ends of the inductors will change so that the current continues to flow. At this time, two current loops will be formed. The first loop is from the power supply through the first inductor L1 with energy storage, then through the second capacitor C2, then through the first diode D1, and finally through the load R1. This load is formed by R1 and C3 in parallel to form a loop. The second loop is discharged by the second inductor L2 with energy storage, passes through the first diode D1, and then passes through the load to form a loop. At this stage, the power supply voltage and not only supply power to the load first resistor R1, but also charge the second capacitor C2.

[0079] In this way, the power control signal SW controls the first switch Q1 to work in a switching manner, and the load always has a stable voltage output. The third decoupling capacitor C3 is added in the later stage. The high-frequency impedance characteristics of the decoupling capacitor can effectively bypass the interference signal, thereby reducing the interference signal caused by the switching frequency switching. The stable power output of the later stage ensures the normal operation of the programmable attenuator.

[0080] This method solves the problem that different external power supply voltages require the replacement of attenuator models, reduces the test workflow during testing, and greatly reduces the risk of burning the attenuator due to adding the wrong voltage; in addition, after reducing the V2 voltage, the power consumption of the attenuator is reduced by about 30%. At the same time, for attenuator manufacturers, the number of product models is reduced, which helps to reduce product management costs. The above improvements have greatly improved the performance and practicality of existing programmable attenuators.

[0081] A voltage conversion circuit 20 is added to the front end of the internal power supply of the programmable attenuator. The voltage conversion circuit 20 has a step-up and step-down power supply conversion capability and can convert a wide voltage input into a stable voltage output.

[0082] The above invention adds a voltage conversion circuit 20 before the attenuation selection circuit 40, so that the voltage range of the working power input can be processed as long as it is within the range processed by the voltage conversion circuit 20, so that the attenuation working voltage provided to the attenuation selection circuit 40 can be maintained within the preset range, thereby solving the technical problem that the attenuator is easily burned out due to the wrong working voltage.

[0083] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. Similarly, in order to simplify the present invention and help understand one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, the various features of the embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. Wherein, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself is a separate embodiment of the present invention.

[0084] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and further may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive.

[0085] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

Claims

1. A programmable attenuator, characterized in that: The programmable attenuator comprises: Power input terminal, used to connect to the working power supply; A voltage conversion circuit, connected to the power input terminal and used for converting the voltage of the working power supply to an attenuated working voltage within a preset range; a switch driving circuit, connected to the voltage conversion circuit, for receiving a driving signal; and an attenuation gating circuit, connected to the switch driving circuit and the voltage conversion circuit respectively, the attenuation gating circuit having a first attenuation path and a second attenuation path, and when the attenuation working voltage is connected, the first attenuation path or the second attenuation path is turned on according to the driving signal; The switch driving circuit includes a first inverter, a first operation gate, a second operation gate, a first triode, a second triode, a second diode and a third diode. The input end of the first inverter is connected to the first input end of the first operation gate for receiving the driving signal. The output end of the first inverter is connected to the first input end of the second operation gate; the second input end of the first operation gate is connected to the second input end of the second operation gate for receiving a logic level in a preset range; the output end of the first operation gate is connected to the first end of the first triode, the second end of the first triode is connected to the cathode of the second diode, and the connection node thereof outputs the processed driving signal. The third end of the first triode, the third end of the second triode, the anode of the second diode and the anode of the third diode are all grounded; the output end of the second operation gate is connected to the first end of the second triode; the second end of the second triode is connected to the cathode of the third diode, and the connection node thereof outputs the processed driving signal.

2. The programmable attenuator according to claim 1, characterized in that: The power input end includes a positive power input end and a negative power input end. The voltage conversion circuit includes a first inductor, a first capacitor, a first switch, a second inductor, a first diode, a second capacitor, a third capacitor and a first resistor. The first end of the first inductor is connected to the positive power input end and the first end of the first capacitor respectively, and a connection node thereof is connected to a positive power supply. The second end of the first inductor, the first end of the first switch and the first end of the second capacitor are interconnected. The controlled end of the first switch is connected to a power control signal, and the second end of the second capacitor, the first end of the second inductor and the anode of the first diode are interconnected. The cathode of the first diode, the first end of the third capacitor and the first end of the first resistor are interconnected. When the controlled end of the first switch is connected to the power control signal, the connection node thereof outputs the attenuated working voltage within a preset range. The second end of the third capacitor, the second end of the first resistor, the second end of the second inductor, the second end of the first switch, the second end of the first capacitor and the negative power input end are grounded.

3. The programmable attenuator according to claim 1, characterized in that: The attenuation gating circuit includes a relay circuit and an attenuation circuit, the relay circuit includes a first controlled end, a second controlled end, a power input end, a power output end and a magnetic end, the attenuation circuit includes a first controlled end, a second controlled end, a radio frequency input end and a radio frequency output end, the first controlled end of the relay circuit is connected to the driving signal, the second controlled end of the relay circuit is connected to the processed driving signal, the power input end of the relay circuit is connected to the attenuation working voltage, the power output end of the relay circuit is grounded, the magnetic end of the relay circuit and the first controlled end and the second controlled end of the attenuation circuit can be magnetically arranged, the radio frequency input end of the attenuation circuit obtains the radio frequency signal to be attenuated, and the radio frequency output end of the attenuation circuit outputs the processed radio frequency signal to be attenuated; The relay circuit is provided with a first relay path and a second relay path, which are used to control the first relay path or the second relay path to be turned on according to the driving signal; The attenuation circuit is provided with the first attenuation path and the second attenuation path, and controls the corresponding attenuation path to be turned on according to the conduction states of the first relay path and the second relay path.

4. The programmable attenuator according to claim 3, characterized in that: The relay circuit includes a fourth diode, a fifth diode, a magnetic holding switch, a first coil and a second coil, the magnetic holding switch includes a controlled end, a first contact, a second contact, a third contact and a fourth contact, the anode of the fourth diode and the anode of the fifth diode are connected, and the connection node is the power input end of the relay circuit, the controlled end of the magnetic holding switch is respectively connected to the cathode of the fourth diode and the cathode of the fifth diode, and connected to the drive signal; the first coil has a first end point, a second end point and a middle end point, the first end point of the first coil is connected to the first end point of the second coil, and the middle end point of the first coil is connected to the attenuation working voltage; When the driving signal is at a high level, the first contact of the magnetic holding switch is suspended, the second contact of the magnetic holding switch is grounded, the third contact of the magnetic holding switch is connected to the second end of the first coil, and the fourth contact of the magnetic holding switch is suspended; When the driving signal is at a low level, the first contact of the magnetic holding switch is grounded, the second contact of the magnetic holding switch is suspended, the fourth contact of the magnetic holding switch is connected to the second end of the first coil, and the third contact of the magnetic holding switch is suspended.

5. The programmable attenuator according to claim 4, characterized in that: The attenuation circuit includes a first magnetic switch, a second magnetic switch, a second resistor, a third resistor and a fourth resistor. The first magnetic switch includes a controlled end, a first connection end, a second connection end and a third connection end. The second magnetic switch includes a controlled end, a first connection end, a second connection end and a third connection end. The controlled end of the first magnetic switch and the controlled end of the second magnetic switch can be magnetically arranged with the second coil. The first connection end of the first magnetic switch is connected to the first connection end of the second magnetic switch, the second connection end of the first magnetic switch is connected to the first end of the second resistor, and the third connection end of the first magnetic switch is connected to the RF signal to be attenuated; the second end of the second resistor, the first end of the third resistor and the first end of the fourth resistor are interconnected; the first end of the third resistor is connected to the second end of the second magnetic switch; the second end of the fourth resistor is grounded; and the third connection end of the second magnetic switch outputs the processed RF signal to be attenuated.

6. The programmable attenuator according to claim 1, characterized in that: The programmable attenuator further comprises a level indication circuit, an input end of the level indication circuit is connected to the processed driving signal, and an output end of the level indication circuit outputs a level indication signal; The level indication circuit is used to detect the processed driving signal and output the processed signal to indicate the level of the driving signal.

7. The programmable attenuator according to claim 6, characterized in that: The level indication circuit includes a second inverter, a fifth resistor and a sixth resistor, the first end of the fifth resistor is the input end of the level indication circuit, the second end of the fifth resistor is respectively connected to the first end of the sixth resistor and the input end of the second inverter, and the second end of the sixth resistor is grounded; the output end of the second inverter is the output end of the level indication circuit.

8. The programmable attenuator according to claim 3, characterized in that: The programmable attenuator further comprises a light-emitting indication circuit, the input end of the light-emitting indication circuit is connected to the processed driving signal, and the power supply end of the light-emitting indication circuit is connected to the light-emitting working power supply; The light-emitting indicating circuit is used to indicate the working status of the relay circuit and the attenuation circuit.

9. The programmable attenuator according to claim 8, characterized in that: The light-emitting indication circuit includes a light-emitting diode, a third inverter, a seventh resistor, an eighth resistor and a ninth resistor, wherein the first end of the seventh resistor is the input end of the light-emitting indication circuit, the second end of the seventh resistor is respectively connected to the first end of the eighth resistor and the input end of the third inverter, and the second end of the eighth resistor is grounded; the output end of the third inverter is connected to the first end of the ninth resistor, and the second end of the ninth resistor is connected to the cathode of the light-emitting diode; the anode of the light-emitting diode is the power supply end of the light-emitting indication circuit.

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