Radio frequency circuit and electric appliance
By replacing the RF switch with a circulator and isolator, the peripheral circuit structure of the RF circuit is simplified, the cost is reduced, and the signal receiving unit is protected by a limiter, which solves the problem of high cost in the prior art and achieves fault detection and improved robustness.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DALIAN GONGJIN TECH CO LTD
- Filing Date
- 2025-07-22
- Publication Date
- 2026-06-05
AI Technical Summary
Existing time-division duplex RF circuits use active RF switches, resulting in complex peripheral circuits and high costs.
By replacing the RF switch with passive components such as circulators and isolators, the switching between the first path between the signal transmitting unit and the antenna and the second path between the antenna and the signal receiving unit is realized, simplifying the peripheral circuit structure.
It reduces the cost of time-division duplex RF circuits and protects the signal receiving unit with a limiter, improving robustness and enabling fault detection and prevention.
Smart Images
Figure CN224329464U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of radio frequency technology, and in particular relates to a radio frequency circuit and electrical device. Background Technology
[0002] In existing time-division duplex radio frequency circuits, there are usually radio frequency switches, signal transmitting units, signal receiving units and antennas. The switching between the first path between the signal transmitting unit and the antenna and the second path between the antenna and the signal receiving unit is achieved by the radio frequency switch.
[0003] Because RF switches are active devices, and they require time-division duplex switching logic to switch between the first and second paths, their peripheral circuitry is complex and requires extensive debugging to function properly. It is evident that existing time-division duplex RF circuits are relatively expensive. Summary of the Invention
[0004] In view of this, embodiments of this application provide a radio frequency circuit and electrical device to solve the technical problem of high cost of existing time-division duplex radio frequency circuits.
[0005] In a first aspect, embodiments of this application provide a radio frequency circuit, the radio frequency circuit including a signal transmitting unit, a signal receiving unit, a circulator, an isolator, and an antenna; the output terminal of the signal transmitting unit is connected to a first terminal of the circulator, the second terminal of the circulator is connected to the antenna, the third terminal of the circulator is connected to the input terminal of the isolator, and the output terminal of the isolator is connected to the input terminal of the signal receiving unit.
[0006] Optionally, the radio frequency circuit further includes a limiter connected between the isolator and the signal receiving unit.
[0007] Optionally, the radio frequency circuit further includes a first coupler and a first detector; the first coupler is connected between the signal transmitting unit and the circulator, and the input terminal of the first detector is connected to the coupling terminal of the first coupler.
[0008] Optionally, the radio frequency circuit further includes a second coupler and a second detector; the second coupler is connected between the circulator and the isolator, and the input terminal of the second detector is connected to the coupling terminal of the second coupler.
[0009] Optionally, the radio frequency circuit further includes a controller, which includes a first input terminal and a second input terminal; the first input terminal of the controller is connected to the output terminal of the first detector, and the second input terminal of the controller is connected to the output terminal of the second detector.
[0010] Optionally, the controller further includes a control terminal, which is connected to the controlled terminal of the signal transmitting unit.
[0011] Optionally, the controller further includes an alarm signal output terminal, which is connected to the target device.
[0012] Optionally, the radio frequency circuit further includes a radio frequency switch and a resistor; the input terminal of the radio frequency switch is connected to the limiter, the first output terminal of the radio frequency switch is connected to the input terminal of the signal receiving unit, the second output terminal of the radio frequency switch is connected to the first terminal of the resistor, and the second terminal of the resistor is grounded.
[0013] Optionally, the resistance value of the resistor is determined according to the function of the radio frequency circuit.
[0014] Secondly, embodiments of this application provide an electrical device, the electrical device including the radio frequency circuit as described in any of the first aspects.
[0015] The radio frequency circuit and electrical device provided in this application have the following beneficial effects:
[0016] The radio frequency (RF) circuit provided in this application includes a signal transmitting unit, a signal receiving unit, a circulator, an isolator, and an antenna. The output terminal of the signal transmitting unit is connected to the first terminal of the circulator, the second terminal of the circulator is connected to the antenna, the third terminal of the circulator is connected to the input terminal of the isolator, and the output terminal of the isolator is connected to the input terminal of the signal receiving unit. The circulator can transmit a first RF signal sent by the signal transmitting unit to the antenna, and can also transmit a second RF signal received by the antenna to the signal receiving unit. The isolator can prevent the first RF signal sent by the signal transmitting unit from being transmitted to the signal receiving unit. In the RF circuit of this application, switching between the first path between the signal transmitting unit and the antenna and the second path between the antenna and the signal receiving unit can be achieved by replacing the RF switch with a circulator and an isolator. Since the circulator and isolator are both passive devices, and their peripheral circuits are simple and require no debugging, the RF circuit provided in this application can reduce the cost of time-division duplex RF circuits. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1A schematic diagram of a conventional time-division duplex radio frequency circuit provided in this application embodiment;
[0019] Figure 2 This is a schematic diagram of the structure of a radio frequency circuit provided in an embodiment of this application;
[0020] Figure 3 This is a schematic diagram of a radio frequency circuit provided in another embodiment of this application;
[0021] Figure 4 A schematic diagram of a radio frequency circuit provided in another embodiment of this application;
[0022] Figure 5 A schematic diagram of a radio frequency circuit provided in another embodiment of this application;
[0023] Figure 6 This application also provides a schematic diagram of the structure of a radio frequency circuit according to another embodiment. Detailed Implementation
[0024] It should be noted that the terminology used in the embodiments of this application is only for explaining specific embodiments of this application and is not intended to limit this application. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, "at least one" or "one or more" means one, two or more. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.
[0025] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.
[0026] This application first provides a schematic diagram of a conventional time-division duplex radio frequency circuit. Please refer to... Figure 1 , Figure 1 This is a schematic diagram of a conventional time-division duplex radio frequency circuit provided in an embodiment of this application.
[0027] like Figure 1As shown, existing time-division duplex radio frequency circuits include radio frequency switches, signal transmitting units, signal receiving units, and antennas.
[0028] The radio frequency switch is used to switch between the first path between the signal transmitting unit and the antenna and the second path between the antenna and the signal receiving unit.
[0029] Since RF switches are active devices and require time-division duplex switching logic control to switch between the first and second paths, their peripheral circuitry is complex and requires complex debugging to function properly, which increases the cost of existing time-division duplex RF circuits.
[0030] Based on this, embodiments of this application provide a radio frequency circuit to solve the technical problem of high cost of existing time-division duplex radio frequency circuits.
[0031] Please see Figure 2 , Figure 2 This is a schematic diagram of a radio frequency circuit provided in an embodiment of this application.
[0032] like Figure 2 As shown, the radio frequency circuit may include a signal transmitting unit 11, a signal receiving unit 12, a circulator 13, an isolator 14, and an antenna 15.
[0033] The output of the signal transmitting unit 11 is connected to the first end of the circulator 13, the second end of the circulator 13 is connected to the antenna 15, the third end of the circulator 13 is connected to the input of the isolator 14, and the output of the isolator 14 is connected to the input of the signal receiving unit 12.
[0034] The circulator 13 can be used to transmit the first radio frequency signal sent by the signal transmitting unit 11 to the antenna 15, and can also be used to transmit the second radio frequency signal received by the antenna 15 to the signal receiving unit 12. It should be noted that the second radio frequency signal received by the antenna 15 is a signal sent by a device other than the radio frequency circuit, and not the first radio frequency signal sent by the signal transmitting unit 11.
[0035] Isolator 14 can be used to prevent the first radio frequency signal sent by signal transmitting unit 11 from being sent to signal receiving unit 12.
[0036] The signal transmitting unit 11 can be used to transmit the first radio frequency signal in the signal transmitting unit 11 to the circulator 13 to instruct the circulator 13 to transmit the first radio frequency signal to the antenna 15.
[0037] The signal receiving unit 12 can be used to receive the second radio frequency signal sent by the circulator 13.
[0038] Antenna 15 can be used to transmit a first radio frequency signal after receiving a first radio frequency signal transmitted by circulator 13. It can also be used to transmit a second radio frequency signal to circulator 13 after receiving a second radio frequency signal transmitted by a device other than the radio frequency circuit, so as to instruct circulator 13 to transmit the second radio frequency signal to signal receiving unit 12.
[0039] In the embodiments of this application, both the circulator 13 and the isolator 14 are passive devices. The peripheral circuits of the circulator 13 and the isolator 14 are relatively simple, and the circulator 13 and the isolator 14 do not require debugging in actual applications.
[0040] As can be seen from the above, the radio frequency circuit provided in this application includes a signal transmitting unit, a signal receiving unit, a circulator, an isolator, and an antenna. The output terminal of the signal transmitting unit is connected to the first terminal of the circulator, the second terminal of the circulator is connected to the antenna, the third terminal of the circulator is connected to the input terminal of the isolator, and the output terminal of the isolator is connected to the input terminal of the signal receiving unit. The circulator can be used to transmit a first radio frequency signal sent by the signal transmitting unit to the antenna, and can also be used to transmit a second radio frequency signal received by the antenna to the signal receiving unit. The isolator can be used to prevent the first radio frequency signal sent by the signal transmitting unit from being transmitted to the signal receiving unit. In the radio frequency circuit of this application, switching between the first path between the signal transmitting unit and the antenna and the second path between the antenna and the signal receiving unit can be achieved by replacing the radio frequency switch with a circulator and an isolator. Since both the circulator and the isolator are passive devices, and their peripheral circuits are simple and require no debugging, the radio frequency circuit provided in this application can reduce the cost of time-division duplex radio frequency circuits.
[0041] Please see Figure 3 , Figure 3 This is a schematic diagram of a radio frequency circuit provided in another embodiment of this application.
[0042] like Figure 3 As shown, this embodiment is similar to Figure 2 One of the differences in the corresponding embodiments is that the radio frequency circuit provided in this embodiment also includes a limiter 16.
[0043] The limiter 16 can be connected between the isolator 14 and the signal receiving unit 12.
[0044] The limiter 16 can be used to limit the radio frequency signal sent by the circulator 13 to the signal receiving unit 12. Specifically, the limiter 16 can be used to reduce the amplitude of radio frequency signals with an amplitude greater than a preset amplitude threshold, so that the amplitude of the radio frequency signal received by the signal receiving unit 12 is less than or equal to the preset amplitude threshold.
[0045] The reason for setting the limiter 16 in the radio frequency circuit is that in practical applications, there may be a situation where the impedance matching of the antenna 15 is mismatched, such as poor antenna contact. When the impedance matching of the antenna 15 is mismatched, the high-power first radio frequency signal emitted by the signal transmitting unit 11 is transmitted to the antenna 15 through the circulator 13. Due to the impedance matching mismatch of the antenna 15, the high-power first radio frequency signal will be transmitted to the signal receiving unit 12 through the antenna 15, the circulator 13 and the isolator 14. The high-power first radio frequency signal will cause damage to the signal receiving unit 12. Specifically, the high-power first radio frequency signal will cause damage to the low-noise amplifier in the signal receiving unit 12.
[0046] As can be seen from the above, by setting a limiter 16 in the radio frequency circuit, the signal receiving unit 12 can be prevented from being damaged due to impedance mismatch of the antenna 15, thus protecting the signal receiving unit 12 and improving the robustness of the radio frequency circuit.
[0047] Please see Figure 4 , Figure 4 This is a schematic diagram of a radio frequency circuit provided in another embodiment of this application.
[0048] like Figure 4 As shown, this embodiment is similar to Figure 3 One of the differences between the corresponding embodiments is that the radio frequency circuit provided in this embodiment further includes a first coupler 17 and a first detector 18.
[0049] The first coupler 17 is connected between the signal transmitting unit 11 and the circulator 13, and the input terminal of the first detector 18 is connected to the coupling terminal of the first coupler 17.
[0050] like Figure 4 As shown, this embodiment is similar to Figure 3 One of the differences between the corresponding embodiments is that the radio frequency circuit provided in this embodiment also includes a second coupler 19 and a second detector 20.
[0051] The second coupler 19 is connected between the circulator 13 and the isolator 14, and the input terminal of the second detector 20 is connected to the coupling terminal of the second coupler 19.
[0052] The first coupler 17 can be used to detect the radio frequency power of the first radio frequency signal transmitted by the signal transmitting unit 11.
[0053] The first detector 18 can be used to convert the radio frequency power of the first radio frequency signal detected by the first coupler 17 into a voltage signal, so that the user can determine the radio frequency power of the first radio frequency signal based on the voltage signal output by the first detector 18, thereby determining whether the first radio frequency signal sent by the signal transmitting unit 11 is within the preset first radio frequency power range. If it is determined that the first radio frequency signal sent by the signal transmitting unit 11 is not within the preset first radio frequency power range, the user can determine that the signal transmitting unit 11 has malfunctioned.
[0054] The second coupler 19 can be used to detect the radio frequency power of the second radio frequency signal sent by the circulator 13 to the signal receiving unit 12.
[0055] The second detector 20 can be used to convert the radio frequency power of the second radio frequency signal detected by the second coupler 19 into a voltage signal, so that the user can determine the radio frequency power of the second radio frequency signal based on the voltage signal output by the second detector 20. This allows the user to determine whether the second radio frequency signal sent by the circulator 13 to the signal receiving unit 12 is within the preset second radio frequency power range. If it is determined that the second radio frequency signal sent by the circulator 13 to the signal receiving unit 12 is not within the preset second radio frequency power range, the user can determine that the radio frequency circuit has an impedance mismatch of the antenna 15.
[0056] In addition, the voltage signal output by the first detector 18 and the voltage signal output by the second detector 20 can also be used to allow the user to determine the ratio of the RF power of the first RF signal to the RF power of the second RF signal, thereby determining whether the ratio of the RF power of the first RF signal to the RF power of the second RF signal is within a preset RF power ratio range. If it is determined that the ratio of the RF power of the first RF signal to the RF power of the second RF signal is not within the preset RF power ratio range, the user can determine that the RF circuit has malfunctioned.
[0057] Please see Figure 5 , Figure 5 This is a schematic diagram of a radio frequency circuit provided in another embodiment of this application.
[0058] like Figure 5 As shown, this embodiment is similar to Figure 4 One of the differences in the corresponding embodiments is that the radio frequency circuit provided in this embodiment also includes a controller 21.
[0059] The controller 21 may include a first input terminal and a second input terminal; the first input terminal of the controller 21 is connected to the output terminal of the first detector 18, and the second input terminal of the controller 21 is connected to the output terminal of the second detector 20. The controller 21 may also include a control terminal, which is connected to the controlled terminal of the signal transmitting unit 11. The controller 21 also includes an alarm signal output terminal, which is connected to the target device.
[0060] The controller 21 can be used to acquire the voltage signal output by the output terminal of the first detector 18 through the first input terminal, and can determine the radio frequency power of the first radio frequency signal based on the voltage signal output by the first detector 18, thereby determining whether the first radio frequency signal sent by the signal transmitting unit 11 is within the preset first radio frequency power range. If it is determined that the first radio frequency signal sent by the signal transmitting unit 11 is not within the preset first radio frequency power range, the controller 21 can determine that the signal transmitting unit 11 has malfunctioned.
[0061] The controller 21 can also be used to acquire the voltage signal output from the output terminal of the second detector 20 through the second input terminal, and determine the RF power of the second RF signal based on the voltage signal output by the second detector 20. This allows the controller to determine whether the second RF signal sent by the circulator 13 to the signal receiving unit 12 is within the preset second RF power range. If it is determined that the second RF signal sent by the circulator 13 to the signal receiving unit 12 is not within the preset second RF power range, the controller 21 can determine that the RF circuit has an impedance mismatch of the antenna 15.
[0062] The controller 21 can also be used to determine the ratio of the RF power of the first RF signal to the RF power of the second RF signal after determining the RF power of the first RF signal and the RF power of the second RF signal, thereby determining whether the ratio of the RF power of the first RF signal to the RF power of the second RF signal is within a preset RF power ratio range. If it is determined that the ratio of the RF power of the first RF signal to the RF power of the second RF signal is not within the preset RF power ratio range, the controller 21 can determine that the RF circuit has malfunctioned.
[0063] The controller 21 can also be used to send a shutdown signal to the signal transmitting unit 11 via the control terminal after determining that the antenna 15 impedance mismatch has occurred in the radio frequency circuit, so as to control the signal transmitting unit 11 to stop transmitting the first radio frequency signal.
[0064] The controller 21 can also be used to output an alarm signal to the target device through the alarm signal output terminal to alert the user that the radio frequency circuit has malfunctioned after determining that the signal transmitting unit 11 has failed, or that the radio frequency circuit has an impedance mismatch of the antenna 15. In practical applications, the target device may include, but is not limited to, the controller of the radio frequency base station.
[0065] Please see Figure 6 , Figure 6 This application also provides a schematic diagram of the structure of a radio frequency circuit according to another embodiment.
[0066] like Figure 6 As shown, this embodiment is similar to Figure 5 One of the differences in the corresponding embodiments is that the radio frequency circuit provided in this embodiment also includes a radio frequency switch 22 and a resistor 23.
[0067] The input terminal of the RF switch 22 is connected to the limiter 16, the first output terminal of the RF switch 22 is connected to the input terminal of the signal receiving unit 12, the second output terminal of the RF switch 22 is connected to the first terminal of the resistor 23, and the second terminal of the resistor 23 is grounded.
[0068] The radio frequency switch 22 can be used to control the switching of the signal receiving unit 12. Specifically, the radio frequency switch 22 can be used to control the switching of the low noise amplifier in the signal receiving unit 12.
[0069] In practical applications, since the RF circuit is equipped with a limiter 16 for protection, the power carrying capacity of the RF switch 22 can be very small. Therefore, an RF switch with a power lower than the preset power threshold can be used as the RF switch 22 to further reduce the cost of the time-division duplex RF circuit.
[0070] Resistor 23 can be used to provide impedance matching for circulator 13 when signal receiving unit 12 is off, thereby avoiding the lack of corresponding impedance matching for circulator 13 when signal receiving unit 12 is off.
[0071] In practical applications, the resistance value of resistor 23 can be determined according to the function of the RF circuit. For example, the resistance value of resistor 23 can be 50 ohms.
[0072] This application provides an electrical device that includes the radio frequency circuit provided in any embodiment of this application.
[0073] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, refer to the relevant descriptions of other embodiments.
[0074] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0075] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.
Claims
1. A radio frequency circuit, characterized in that, The radio frequency circuit includes a signal transmitting unit, a signal receiving unit, a circulator, an isolator, and an antenna; the output terminal of the signal transmitting unit is connected to the first terminal of the circulator, the second terminal of the circulator is connected to the antenna, the third terminal of the circulator is connected to the input terminal of the isolator, and the output terminal of the isolator is connected to the input terminal of the signal receiving unit.
2. The radio frequency circuit according to claim 1, characterized in that, The radio frequency circuit also includes a limiter connected between the isolator and the signal receiving unit.
3. The radio frequency circuit according to claim 2, characterized in that, The radio frequency circuit further includes a first coupler and a first detector; the first coupler is connected between the signal transmitting unit and the circulator, and the input terminal of the first detector is connected to the coupling terminal of the first coupler.
4. The radio frequency circuit according to claim 3, characterized in that, The radio frequency circuit also includes a second coupler and a second detector; the second coupler is connected between the circulator and the isolator, and the input terminal of the second detector is connected to the coupling terminal of the second coupler.
5. The radio frequency circuit according to claim 4, characterized in that, The radio frequency circuit also includes a controller, which has a first input terminal and a second input terminal; the first input terminal of the controller is connected to the output terminal of the first detector, and the second input terminal of the controller is connected to the output terminal of the second detector.
6. The radio frequency circuit according to claim 5, characterized in that, The controller also includes a control terminal, which is connected to the controlled terminal of the signal transmitting unit.
7. The radio frequency circuit according to claim 5, characterized in that, The controller also includes an alarm signal output terminal, which is connected to the target device.
8. The radio frequency circuit according to claim 5, characterized in that, The radio frequency circuit also includes a radio frequency switch and a resistor; the input terminal of the radio frequency switch is connected to the limiter, the first output terminal of the radio frequency switch is connected to the input terminal of the signal receiving unit, the second output terminal of the radio frequency switch is connected to the first terminal of the resistor, and the second terminal of the resistor is grounded.
9. The radio frequency circuit according to claim 8, characterized in that, The resistance value of the resistor is determined according to the function of the radio frequency circuit.
10. An electrical appliance, characterized in that, The electrical device includes the radio frequency circuit as described in any one of claims 1 to 9.