Programmable attenuator

Abstract

The utility model relates to the technical field of communication, in particular to a programmable attenuator. The programmable attenuator comprises a signal input end, a signal output end, an adjustable attenuation unit, a first impedance matching unit, a second impedance matching unit, a control unit and a communication unit, the first impedance matching unit is arranged between the signal input end and the adjustable attenuation unit, and the second impedance matching unit is arranged between the adjustable attenuation unit and the signal output end. The communication unit is used for receiving an external attenuation control instruction, the control unit is connected with the communication unit and the adjustable attenuation unit, and the control unit is used for adjusting the attenuation value of the adjustable attenuation unit according to the attenuation control instruction received by the communication unit and attenuating a signal input by the signal input end. The application can meet the use requirements of an application scene of dynamically adjusting the signal strength, reduce the total cost, and improve the reliability and stability of signal transmission.

Description

Technical Field

[0001] This utility model relates to the field of communication technology, and in particular to a programmable attenuator. Background Technology

[0002] With the development of the communications field, attenuators are crucial instruments in radio frequency and microwave systems. They are indispensable in many microwave systems, such as radar, multi-channel communication systems, and other measurements of power transmission loss and received signals. The sensitivity and measurement accuracy of attenuators are closely related to the smooth operation of production. The development of microwave equipment components, testing systems, and testing technologies is inseparable from attenuators. Attenuators are widely used in the measurement of electronic instruments, electromagnetic compatibility testing, and internal attenuation of measuring instruments, etc. Their performance directly affects the accuracy of testing and the precision of measuring instruments.

[0003] Wireless radio frequency (RF) signals attenuate significantly with increasing distance, exhibiting a non-linear attenuation that decreases exponentially. This can negatively impact signal stability and reliability. Therefore, attenuators can be used to effectively control the attenuation of RF signals. Currently, attenuators have fixed attenuation values ​​and cannot be adjusted for different signal strengths. This limits their use in applications requiring dynamic signal strength adjustment, often necessitating replacement of attenuators based on changing needs. This results in high overall costs and unsatisfactory signal transmission stability and reliability. Utility Model Content

[0004] The technical problem to be solved by this utility model embodiment is to provide a programmable attenuator to solve the problems that the existing attenuators cannot meet the application requirements of dynamically adjusting signal strength, have high overall cost, and have unsatisfactory stability and reliability of signal transmission.

[0005] This utility model discloses a programmable attenuator, including a signal input terminal, a signal output terminal, an adjustable attenuation unit, a first impedance matching unit, a second impedance matching unit, a control unit, and a communication unit. The first impedance matching unit is disposed between the signal input terminal and the adjustable attenuation unit, and the second impedance matching unit is disposed between the adjustable attenuation unit and the signal output terminal. The communication unit is used to receive external attenuation control commands. The control unit is connected to the communication unit and the adjustable attenuation unit. The control unit is used to adjust the attenuation value of the adjustable attenuation unit according to the attenuation control commands received by the communication unit, thereby attenuating the signal input to the signal input terminal.

[0006] Optionally, the adjustable attenuation unit includes a first adjustable attenuation circuit and a second adjustable attenuation circuit connected in series with the first adjustable attenuation circuit, and the control terminals of both the first adjustable attenuation circuit and the second adjustable attenuation circuit are connected to the control unit.

[0007] Optionally, the first adjustable attenuation circuit includes a first adjustable attenuation chip, the second adjustable attenuation circuit includes a second adjustable attenuation chip, the first adjustable attenuation chip and the second adjustable attenuation chip are connected in series, and the control pins of the first adjustable attenuation chip and the second adjustable attenuation chip are both connected to the control unit.

[0008] Optionally, the maximum attenuation value of the first adjustable attenuation chip and / or the second adjustable attenuation chip is 30dB.

[0009] Optionally, the communication unit includes a communication chip and a communication interface, the control unit includes a microcontroller, the communication chip is connected to the communication interface and the microcontroller, and the control pins of the first adjustable attenuation chip and the second adjustable attenuation chip are both connected to the microcontroller.

[0010] Optionally, the communication chip is a serial port chip, and the communication interface is a serial port.

[0011] Optionally, the serial port includes one of an RS-232 interface, an RS-485 interface, and an RS-422 interface.

[0012] Optionally, the first impedance matching unit includes a first resistor, a first capacitor, and a second capacitor. The first resistor is connected in series between the signal input terminal and the adjustable attenuation unit. One end of the first capacitor is connected to the first end of the first resistor, and the other end is grounded. One end of the second capacitor is connected to the second end of the first resistor, and the other end is grounded.

[0013] Optionally, the second impedance matching unit includes a second resistor, a third capacitor, and a fourth capacitor. The second resistor is connected in series between the signal output terminal and the adjustable attenuation unit. One end of the third capacitor is connected to the first end of the second resistor, and the other end is grounded. One end of the fourth capacitor is connected to the second end of the second resistor, and the other end is grounded.

[0014] Compared with the prior art, the beneficial effects of the programmable attenuator provided in this utility model embodiment are as follows: by setting a communication unit to obtain external attenuation control commands, the control unit adjusts the attenuation value of the adjustable attenuation unit based on the external attenuation control commands, thereby attenuating the signal input at the signal input terminal and outputting it from the signal output terminal for subsequent processing and transmission, meeting the application requirements of dynamically adjusting signal strength. There is no need to replace the attenuator according to the dynamic adjustment requirements, reducing the overall cost. Furthermore, a first impedance matching unit is set between the signal input terminal and the adjustable attenuation unit, and a second impedance matching unit is set between the signal output terminal and the adjustable attenuation unit, which can reduce energy loss, reduce signal reflection, improve signal quality and transmission efficiency, ensure signal stability during transmission, and improve the reliability and stability of the programmable attenuator for signal transmission. Attached Figure Description

[0015] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0016] Figure 1 This is a structural block diagram of the programmable attenuator provided in an embodiment of the present invention;

[0017] Figure 2 This is a circuit diagram of a programmable attenuator provided in an embodiment of the present invention.

[0018] The labels for the attached figures are as follows:

[0019] 110. Signal input terminal; 120. Signal output terminal; 130. Adjustable attenuation unit; 131. First adjustable attenuation circuit; 132. Second adjustable attenuation circuit; 140. First impedance matching unit; 150. Second impedance matching unit; 160. Control unit; 170. Communication unit; 171. Communication chip; 172. Communication interface;

[0020] U1, First adjustable attenuation chip; U2, Second adjustable attenuation chip; U3, Serial port chip; U4, Microcontroller; J1, Serial port; R1, First resistor; R2, Second resistor; C1, First capacitor; C2, Second capacitor; C3, Third capacitor; C4, Fourth capacitor. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The preferred embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0022] This utility model embodiment provides a programmable attenuator, such as Figure 1As shown, the programmable attenuator includes a signal input terminal 110, a signal output terminal 120, an adjustable attenuation unit 130, a first impedance matching unit 140, a second impedance matching unit 150, a control unit 160, and a communication unit 170. The first impedance matching unit 140 is disposed between the signal input terminal 110 and the adjustable attenuation unit 130, and the second impedance matching unit 150 is disposed between the adjustable attenuation unit 130 and the signal output terminal 120. The communication unit 170 is used to receive external attenuation control commands. The control unit 160 is connected to the communication unit 170 and the adjustable attenuation unit 130. The control unit 160 is used to adjust the attenuation value of the adjustable attenuation unit 130 according to the attenuation control commands received by the communication unit 170, thereby attenuating the signal input to the signal input terminal 110.

[0023] The programmable attenuator in this embodiment acquires external attenuation control commands through a communication unit 170. The control unit 160 adjusts the attenuation value of the adjustable attenuation unit 130 based on the external attenuation control commands, thereby attenuating the signal input at the signal input terminal 110 and outputting it from the signal output terminal 120 for subsequent processing and transmission. This meets the application requirements of dynamically adjusting signal strength, eliminating the need to replace the attenuator according to dynamic adjustment requirements, thus reducing overall costs. Furthermore, a first impedance matching unit 140 is provided between the signal input terminal 110 and the adjustable attenuation unit 130, and a second impedance matching unit 150 is provided between the signal output terminal 120 and the adjustable attenuation unit 130. This reduces energy loss, reduces signal reflection, improves signal quality and transmission efficiency, ensures signal stability during transmission, and enhances the reliability and stability of the programmable attenuator for signal transmission.

[0024] In an optional embodiment of this application, the adjustable attenuation unit 130 includes a first adjustable attenuation circuit 131 and a second adjustable attenuation circuit 132 connected in series with the first adjustable attenuation circuit 131. The control terminals of the first adjustable attenuation circuit 131 and the second adjustable attenuation circuit 132 are both connected to the control unit 160.

[0025] By setting up the first adjustable attenuation circuit 131 and the second adjustable attenuation circuit 132 and connecting them in series, the attenuation value range of the adjustable attenuation unit 130 can be expanded, and the maximum attenuation value of the adjustable attenuation unit 130 can be expanded to the sum of the attenuation values ​​of the two adjustable attenuation circuits, providing a wider attenuation range to meet different testing requirements; the attenuation value of the adjustable attenuation circuits can be adjusted separately to achieve finer attenuation control, which helps to improve the accuracy of signal conditioning.

[0026] refer to Figure 1 and Figure 2In an optional embodiment of this application, the first adjustable attenuation circuit 131 includes a first adjustable attenuation chip U1, and the second adjustable attenuation circuit 132 includes a second adjustable attenuation chip U2. The first adjustable attenuation chip U1 and the second adjustable attenuation chip U2 are connected in series, and the control pins of the first adjustable attenuation chip U1 and the second adjustable attenuation chip U2 are both connected to the control unit 160.

[0027] Both the first adjustable attenuation circuit 131 and the second adjustable attenuation circuit 132 employ adjustable attenuation chips. Through digital control, users can more precisely adjust the attenuation of the programmable attenuator to meet different input signal strengths and output requirements. Furthermore, the high internal circuit integration of the adjustable attenuation chip reduces the need for external components, saves circuit board space, and contributes to the miniaturization of the programmable attenuator. The series-connected first adjustable attenuation chip U1 and second adjustable attenuation chip U2 can be combined to achieve the required attenuation value, providing flexible attenuation control.

[0028] In an optional embodiment of this application, the maximum attenuation value of the first adjustable attenuation chip U1 and / or the second adjustable attenuation chip U2 is 30dB.

[0029] The first adjustable attenuator chip U1 and the second adjustable attenuator chip U2 employ a maximum attenuation value of 30dB, which can meet the signal attenuation requirements of many applications, such as communication systems, measuring instruments, and RF equipment where precise signal control and adjustment are required. When the first adjustable attenuator chip U1 and the second adjustable attenuator chip U2 are connected in series, they can provide attenuation from 0-60dB in 1dB steps, offering more precise control steps. This allows users to perform precise power adjustments, meeting the different signal strength requirements of various test environments and equipment, providing more experimental conditions and configurations, and facilitating broader testing and analysis. In communication systems, programmable attenuators can be used to optimize system performance by adjusting the attenuation value to match different channel conditions and equipment characteristics, thereby improving system reliability and efficiency.

[0030] The microcontroller U4 can adjust the attenuation values ​​of the first adjustable attenuation chip U1 and the second adjustable attenuation chip U2 by pre-setting an attenuation control command with a corresponding attenuation step size. When the microcontroller U4 receives the corresponding attenuation control command, it controls the first adjustable attenuation chip U1 and the second adjustable attenuation chip U2 to adjust the signal strength according to the pre-set attenuation step size, thereby attenuating the signal input to the signal input terminal 110 accordingly.

[0031] refer to Figure 1 and Figure 2In an optional embodiment of this application, the communication unit 170 includes a communication chip 171 and a communication interface 172, the control unit 160 includes a microcontroller U4, the communication chip 171 is connected to the communication interface 172 and the microcontroller U4, and the control pins of the first adjustable attenuation chip U1 and the second adjustable attenuation chip U2 are both connected to the microcontroller U4.

[0032] By setting up communication interface 172, an external host computer can be connected to obtain attenuation control commands. Communication chip 171 can convert these external attenuation control commands into a format readable by the microcontroller U4, such as converting the host computer's attenuation control commands to TTL level for communication with the microcontroller U4, enabling the microcontroller U4 to correctly read the external serial port J1 commands. The microcontroller U4 can communicate with the external host computer through communication chip 171 and communication interface 172, and also communicate with the control pins of the first adjustable attenuation chip U1 and the second adjustable attenuation chip U2 to adjust their attenuation values. The programmable attenuator allows users to adjust the attenuation value according to actual application needs, which is very useful in scenarios requiring dynamic signal strength adjustment. For example, in a GNSS signal acquisition and playback instrument, the programmable attenuator can adjust the output power to match the requirements under different test conditions.

[0033] Optionally, the communication chip 171 is a serial port chip U3, and the communication interface 172 is a serial port J1. The communication unit 170 adopts the serial port J1 communication method. Compared with other communication methods, the serial port J1 communication method has simple hardware, requiring only two signal lines (transmit line and receive line) and a ground line to realize data transmission, which is low cost. Moreover, the serial port J1 communication protocol is relatively simple and easy to program and debug. Serial port J1 communication (such as RS-485 interface) uses differential signal transmission, which can effectively resist external interference and help to attenuate the stability of control command transmission.

[0034] Optionally, serial port J1 includes one of RS-232, RS-485, and RS-422 interfaces. For example, serial port J1 uses an RS-232 interface. The serial port chip U3 converts the attenuation control command into a TTL level to communicate with the microcontroller U4, enabling the microcontroller U4 to correctly read the external serial port J1 commands.

[0035] In other embodiments, the communication unit 170 may also use a USB interface and a corresponding communication chip 171 to transmit external attenuation control commands to the microcontroller U4.

[0036] refer to Figure 1 and Figure 2In an optional embodiment of this application, the first impedance matching unit 140 includes a first resistor R1, a first capacitor C1, and a second capacitor C2. The first resistor R1 is connected in series between the signal input terminal 110 and the adjustable attenuation unit 130. One end of the first capacitor C1 is connected to the first end of the first resistor R1, and the other end is grounded. One end of the second capacitor C2 is connected to the second end of the first resistor R1, and the other end is grounded.

[0037] The first resistor R1, the first capacitor C1, and the second capacitor C2 are configured to form the first impedance matching unit 140. By reasonably selecting the parameters of the resistor and capacitor, the source impedance of the input signal can be matched with the input impedance of the adjustable attenuation unit 130, thereby maximizing power transmission and reducing reflection, and improving signal integrity. This is especially important for high-speed signals and long-distance transmission.

[0038] When the adjustable attenuation unit 130 uses a first adjustable attenuation chip U1 and a second adjustable attenuation chip U2 connected in series, the first resistor R1 is connected in series between the signal input terminal 110 and the first adjustable attenuation chip U1.

[0039] refer to Figure 1 and Figure 2 In an optional embodiment of this application, the second impedance matching unit 150 includes a second resistor R2, a third capacitor C3 and a fourth capacitor C4. The second resistor R2 is connected in series between the signal output terminal 120 and the adjustable attenuation unit 130. One end of the third capacitor C3 is connected to the first end of the second resistor R2 and the other end is grounded. One end of the fourth capacitor C4 is connected to the second end of the second resistor R2 and the other end is grounded.

[0040] The second resistor R2, the third capacitor C3, and the fourth capacitor C4 constitute the second impedance matching unit 150. By appropriately selecting the parameters of the resistors and capacitors, the output impedance of the adjustable attenuation unit 130 can be matched with the load impedance of the signal output terminal 120. This maximizes power transmission, reduces signal reflection, and thus improves the efficiency and quality of signal transmission, as well as the integrity of signal transmission. The parameters of the second resistor R2, the third capacitor C3, and the fourth capacitor C4 can be set and adjusted by the designer according to requirements to optimize impedance matching. For example, achieving an impedance matching of 50 ohms can achieve optimal performance.

[0041] When the adjustable attenuation unit 130 uses the first adjustable attenuation chip U1 and the second adjustable attenuation chip U2 connected in series, the second resistor R2 is connected in series between the signal output terminal 120 and the second adjustable attenuation chip U2.

[0042] like Figure 1 and Figure 2 As shown, the specific working principle of the programmable attenuator in this embodiment is as follows;

[0043] External attenuation control commands are received via serial port J1. Serial port chip U3 converts these commands into TTL level signals for communication with microcontroller U4. Microcontroller U4 controls the switches inside the first adjustable attenuation chip U1 and the second adjustable attenuation chip U2 to connect or disconnect appropriate internal resistors, forming the required attenuation network. Different switch combinations can achieve different levels of attenuation. The signal input at signal input terminal 110 passes sequentially through the first impedance matching unit 140, the first adjustable attenuation chip U1, the second adjustable attenuation chip U2, and the second impedance matching unit 150, adjusting the signal amplitude to the set level. The signal output at signal output terminal 120 has a lower amplitude than the input signal, and the required attenuation is the user-defined value. The processed signal is output through signal output terminal 120 and can be used for subsequent processing or transmission.

[0044] The programmable attenuator of this embodiment features high accuracy, programmability, low power consumption, and high stability. The attenuation setting can be flexibly modified via the communication unit 170 to adapt to different application requirements, and it can be widely used in wireless communication, signal processing, testing and measurement, and automatic gain control (AGC) and other fields.

[0045] The programmable attenuator in this application embodiment can be used in GNSS signal transponders to amplify outdoor GNSS satellite signals for indoor transmission. It has a wide adjustable attenuation range (e.g., 0–60 dB) and can flexibly cover signals at different distances (1 meter–20 meters). In the development and production of GNSS navigation products and the research and development of smart terminals, the programmable attenuator is used to simulate different signal conditions to test GNSS signals and ensure that the equipment can function normally in various environments. The programmable attenuator can adjust the strength of the GNSS signal to adapt to different test requirements and environmental conditions, which is crucial for improving the anti-interference capability and signal quality of GNSS signals. In GNSS receivers, the programmable attenuator can be used for anti-interference adaptive nulling technology to improve the receiver's performance in interference environments. By adjusting the attenuation amount, the influence of interference signals can be reduced, improving signal resolution and anti-interference capability. The programmable attenuator can also operate on different frequency bands and be applied in GNSS systems to improve positioning accuracy, especially in densely populated urban areas. In applications requiring high-precision positioning, such as precision agriculture and engineering surveying, the programmable attenuator can be used to adjust the signal to achieve centimeter-level positioning accuracy. Programmable attenuators can also be used in conjunction with other positioning technologies (such as inertial navigation, Wi-Fi positioning, etc.) to provide reliable location information when GNSS signals are limited or lost, especially in fields such as autonomous driving and indoor navigation.

[0046] It should be understood that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some of the technical features; and all such modifications and substitutions should fall within the protection scope of the appended claims of this utility model.

Claims

1. A programmable attenuator, characterized in that, The system includes a signal input terminal, a signal output terminal, an adjustable attenuation unit, a first impedance matching unit, a second impedance matching unit, a control unit, and a communication unit. The first impedance matching unit is disposed between the signal input terminal and the adjustable attenuation unit, and the second impedance matching unit is disposed between the adjustable attenuation unit and the signal output terminal. The communication unit is used to receive external attenuation control commands. The control unit is connected to the communication unit and the adjustable attenuation unit. The control unit is used to adjust the attenuation value of the adjustable attenuation unit according to the attenuation control commands received by the communication unit, thereby attenuating the signal input to the signal input terminal.

2. The programmable attenuator of claim 1, wherein, The adjustable attenuation unit includes a first adjustable attenuation circuit and a second adjustable attenuation circuit connected in series with the first adjustable attenuation circuit. The control terminals of both the first and second adjustable attenuation circuits are connected to the control unit.

3. The programmable attenuator of claim 2, wherein, The first adjustable attenuation circuit includes a first adjustable attenuation chip, and the second adjustable attenuation circuit includes a second adjustable attenuation chip. The first adjustable attenuation chip and the second adjustable attenuation chip are connected in series, and the control pins of the first adjustable attenuation chip and the second adjustable attenuation chip are both connected to the control unit.

4. The programmable attenuator according to claim 3, characterized in that, The maximum attenuation value of the first adjustable attenuation chip and / or the second adjustable attenuation chip is 30dB.

5. The programmable attenuator of claim 3, wherein, The communication unit includes a communication chip and a communication interface, the control unit includes a microcontroller, the communication chip is connected to the communication interface and the microcontroller, and the control pins of the first adjustable attenuation chip and the second adjustable attenuation chip are both connected to the microcontroller.

6. The programmable attenuator of claim 5, wherein, The communication chip is a serial port chip, and the communication interface is a serial port.

7. The programmable attenuator of claim 6, wherein, The serial port includes one of RS-232, RS-485, and RS-422 interfaces.

8. The programmable attenuator according to any one of claims 1-7, characterized in that, The first impedance matching unit includes a first resistor, a first capacitor, and a second capacitor. The first resistor is connected in series between the signal input terminal and the adjustable attenuation unit. One end of the first capacitor is connected to the first end of the first resistor, and the other end is grounded. One end of the second capacitor is connected to the second end of the first resistor, and the other end is grounded.

9. The programmable attenuator according to any one of claims 1-7, wherein, The second impedance matching unit includes a second resistor, a third capacitor, and a fourth capacitor. The second resistor is connected in series between the signal output terminal and the adjustable attenuation unit. One end of the third capacitor is connected to the first end of the second resistor, and the other end is grounded. One end of the fourth capacitor is connected to the second end of the second resistor, and the other end is grounded.

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