Antenna switching circuit, radio frequency module, communication module, harmonic radar and equipment

Abstract

The utility model provides an antenna switching circuit, a radio frequency module, a communication module, a harmonic radar and equipment, and relates to the technical field of wireless communication. In the antenna switching circuit, a first radio frequency end and a second radio frequency end of a first radio frequency switch unit are respectively used for connecting a transmitting antenna and a receiving antenna of a harmonic radar, and a first radio frequency end and a second radio frequency end of a second radio frequency switch unit are respectively used for connecting a transmitter circuit and a receiver circuit of the harmonic radar. The first radio frequency switch unit and the second radio frequency switch unit are used for conducting a radio frequency path between the transmitting antenna and the transmitter circuit under the action that the control end is at a low level; and when the control end is at a high level, a radio frequency path between the receiving antenna and the receiver circuit is conducted. According to the antenna switching circuit, the transmitting antenna and the receiving antenna can work asynchronously, the influence of transmitting antenna signals on receiving antenna signals is eliminated, and the false alarm rate of the harmonic radar is reduced.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and more specifically, to an antenna switching circuit, a radio frequency module, a communication module, a harmonic radar, and equipment. Background Art

[0002] Harmonic radar is a radar system that transmits fundamental signals through a transmitting antenna, receives secondary, tertiary or even higher harmonic signals re-radiated from the target through a receiving antenna, and judges, identifies and detects the target.

[0003] Due to its high sensitivity and low false alarm rate, harmonic radar is widely used in areas such as anti-cheating in education systems and the detection of contraband. However, the transmitting antenna and receiving antenna of harmonic radar operate simultaneously. The signal from the transmitting antenna will affect the signal from the receiving antenna, which can easily lead to a high false alarm rate. Utility Model Content

[0004] In response to the above-mentioned deficiencies in the prior art, the present application provides an antenna switching circuit, a radio frequency module, a communication module, a harmonic radar and a device to solve the problems existing in the prior art.

[0005] The technical solutions adopted in the embodiments of this application are as follows:

[0006] In a first aspect, an embodiment of the present application provides an antenna switching circuit, comprising: a first radio frequency switch unit and a second radio frequency switch unit;

[0007] The first RF end and the second RF end of the first RF switch unit are respectively used to connect the transmitting antenna and the receiving antenna of the harmonic radar, the third RF end of the first RF switch unit is connected to the third RF end of the second RF switch unit, and the first RF end and the second RF end of the second RF switch unit are respectively used to connect the transmitter circuit and the receiver circuit of the harmonic radar;

[0008] The control ends of the first RF switch unit and the second RF switch unit are both used to connect to the baseband processing unit of the harmonic radar; the power ends of the first RF switch unit and the second RF switch unit are both used to connect to a preset power supply module in the harmonic radar;

[0009] The first RF switch unit and the second RF switch unit are used to conduct the RF path between the transmitting antenna and the transmitter circuit when the control end is at a low level; and to conduct the RF path between the receiving antenna and the receiver circuit when the control end is at a high level.

[0010] In a second aspect, an embodiment of the present application provides a radio frequency module for a harmonic radar, comprising at least: the antenna switching circuit, transmitter circuit, receiver circuit, transmitting antenna, and receiving antenna described in any of the above embodiments;

[0011] The transmitting antenna and the receiving antenna are respectively connected to the first RF end and the second RF end of the first RF switch unit in the antenna switching circuit, and the transmitter circuit and the receiver circuit are respectively connected to the first RF end and the second RF end of the second RF switch unit in the antenna switching circuit.

[0012] In a third aspect, an embodiment of the present application provides a wireless communication module for a harmonic radar, comprising at least: a radio frequency module and a baseband processing unit; the radio frequency module comprises: the antenna switching circuit, transmitter circuit, receiver circuit, transmitting antenna, and receiving antenna described in any of the above embodiments;

[0013] The transmitting antenna and the receiving antenna are respectively connected to the first RF terminal and the second RF terminal of the first RF switch unit in the antenna switching circuit, and the transmitter circuit and the receiver circuit are respectively connected to the first RF terminal and the second RF terminal of the second RF switch unit in the antenna switching circuit;

[0014] The first end of the baseband processing unit is connected to the control ends of the first radio frequency switch unit and the second radio frequency switch unit, and the baseband processing unit is also connected to the transmitter circuit and the receiver circuit.

[0015] In a fourth aspect, an embodiment of the present application provides a harmonic radar, comprising at least: the wireless communication module and the signal processing module described in the above embodiment; the wireless communication module is connected to the signal processing module.

[0016] In a fifth aspect, an embodiment of the present application provides a radar detection device, comprising at least: the harmonic radar described in the above embodiment.

[0017] The beneficial effects of the present application are: the present application provides an antenna switching circuit, including a first RF switch unit and a second RF switch unit; the first RF end and the second RF end of the first RF switch unit are respectively used to connect the transmitting antenna and the receiving antenna of the harmonic radar, the third RF end of the first RF switch unit is connected to the third RF end of the second RF switch unit, and the first RF end and the second RF end of the second RF switch unit are respectively used to connect the transmitter circuit and the receiver circuit of the harmonic radar.

[0018] The control ends of the first RF switch unit and the second RF switch unit are both used to connect to the baseband processing unit of the harmonic radar; the power supply ends of the first RF switch unit and the second RF switch unit are both used to connect to the preset power supply module in the harmonic radar, and the first RF switch unit and the second RF switch unit are used to conduct the RF path between the transmitting antenna and the transmitter circuit when the control end is at a low level; and conduct the RF path between the receiving antenna and the receiver circuit when the control end is at a high level.

[0019] The antenna switching circuit of the present application can make the transmitting antenna and the receiving antenna work at different times, eliminate the influence of the transmitting antenna signal on the receiving antenna signal, and reduce the false alarm rate of the harmonic radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 Schematic diagram of the working principle of the harmonic radar provided for this application;

[0022] Figure 2 This is one of the structural diagrams of the antenna switching circuit provided in an embodiment of the present application;

[0023] Figure 3 This is a second structural diagram of the antenna switching circuit provided in an embodiment of the present application;

[0024] Figure 4 A schematic diagram of the structure of the radio frequency module of the harmonic radar provided in an embodiment of the present application;

[0025] Figure 5 A schematic diagram of the structure of the wireless communication module of the harmonic radar provided in an embodiment of the present application;

[0026] Figure 6 A schematic diagram of the structure of the harmonic radar provided in an embodiment of the present application.

[0027] Explanation of the accompanying drawings: 1. First RF switch unit; 2. Second RF switch unit; 11. First RF end of the first RF switch unit; 12. Second RF end of the first RF switch unit; 13. Third RF end of the first RF switch unit; 21. First RF end of the second RF switch unit; 22. Second RF end of the second RF switch unit; 23. Third RF end of the second RF switch unit. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0029] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0030] In the description of this application, it should be noted that if the terms "upper", "lower", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the application is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on this application.

[0031] In addition, the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed" and "connected" should be understood in a broad sense. For example, they may refer to a fixed connection, a detachable connection, or an integral connection. They may refer to a direct connection, an indirect connection via an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0033] It should be noted that, in the absence of conflict, the features in the embodiments of this application can be combined with each other.

[0034] Harmonic radar is a product developed based on the special properties of nonlinear devices. Most electronic products exhibit nonlinearity, that is, when a fundamental signal is transmitted to the target, the target will reflect back the second, third or higher harmonics. It is precisely this radiation characteristic of nonlinear devices that enables harmonic radar to be used to effectively identify and search for various man-made electronic products such as mobile phones, recorders, USB flash drives, eavesdropping devices, miniature cameras, remote controls, etc.

[0035] It should be noted that the following embodiments of the present application only take the harmonic radar transmitting a fundamental signal to the target and the target reflecting the second harmonic as an example, which does not limit the number of harmonics reflected by the target. In actual applications, the solution of the present application can also be used in scenarios where the target reflects the third harmonic or higher harmonics.

[0036] The working principle of harmonic radar is as follows Figure 1 As shown in the figure, when a harmonic radar is operating, the transmitter circuit first transmits a 2.4 GHz fundamental wave through the transmitting antenna. This fundamental wave signal is radiated by nonlinear targets and reflected back as a second harmonic. The second harmonic enters the receiver circuit through the receiving antenna and then enters the processing unit to issue an early warning. When a harmonic radar is operating, its transmitting and receiving antennas operate simultaneously. This inevitably causes the transmitting antenna signal to interfere with the receiving signal, resulting in a high false alarm rate.

[0037] Based on this, the present application provides an antenna switching circuit that can solve the above problems. The antenna switching circuit provided by the present application is specifically described below with reference to the accompanying drawings through multiple examples.

[0038] Figure 2 This is one of the structural diagrams of the antenna switching circuit provided in the embodiment of the present application, such as Figure 2 As shown, the antenna switching circuit includes a first radio frequency switch unit 1 and a second radio frequency switch unit 2.

[0039] Among them, the first RF end 11 and the second RF end 12 of the first RF switch unit are respectively used to connect the transmitting antenna and the receiving antenna of the harmonic radar, the third RF end 13 of the first RF switch unit is connected to the third RF end 23 of the second RF switch unit, and the first RF end 21 and the second RF end 22 of the second RF switch unit are respectively used to connect the transmitter circuit and the receiver circuit of the harmonic radar.

[0040] The power supply ends of the first RF switch unit and the second RF switch unit are both used to connect to a preset power supply module in the harmonic radar. Based on this connection, the first RF switch unit and the second RF switch unit can perform their corresponding work under the power supply state, wherein the preset power supply module is directly provided by the baseband processing unit chip.

[0041] The control ends of the first RF switch unit and the second RF switch unit are both used to connect to the baseband processing unit (Baseband Signal) of the harmonic radar. The first RF switch unit and the second RF switch unit are used to conduct the RF path between the transmitting antenna and the transmitter circuit when the control end is at a low level; and conduct the RF path between the receiving antenna and the receiver circuit when the control end is at a high level.

[0042] The specific working principle is: when the baseband processing unit inputs a low level to the control end of the first RF switch unit and the second RF switch unit, the first RF end of the first RF switch unit is turned on, the first RF switch unit is connected to the transmitting antenna, the first RF end of the second RF switch unit is also turned on, and the second RF switch unit is connected to the transmitter circuit. Then, since the third RF end of the first RF switch unit is connected to the third RF end of the second RF switch unit, the transmitting antenna and the transmitter circuit are connected, and the transmitter circuit of the harmonic radar can transmit the fundamental wave signal in its monitoring direction through the transmitting antenna. At this time, since the second RF ends of the first RF switch unit and the second RF switch unit are not turned on, the receiving antenna and the receiver circuit are not connected to the loop of the antenna switching circuit.

[0043] When the fundamental signal encounters a nonlinear target, the second harmonic will be reflected back. At this time, the baseband processing unit inputs a high level to the control ends of the first RF switch unit and the second RF switch unit. Similarly, the RF path between the receiving antenna and the receiver circuit is connected, and the RF path between the transmitting antenna and the transmitter circuit is disconnected. The receiver circuit of the harmonic radar receives the reflected second harmonic signal through the receiving antenna.

[0044] In the antenna switching circuit provided in this embodiment, the transmitting antenna is a 2.4 GHz antenna and the receiving antenna is a 4.8 GHz antenna, which is suitable for application scenarios of transmitting a 2.4 GHz fundamental signal and receiving a second harmonic (4.8 GHz). Optionally, according to actual usage requirements, the transmitting antenna and the receiving antenna can also be other frequencies, which are applied to scenarios of transmitting a fundamental signal and receiving a third or higher harmonic signal.

[0045] In summary, this embodiment provides an antenna switching circuit that can prevent a transmitting antenna and a receiving antenna from operating simultaneously, thereby eliminating the influence of the transmitting antenna signal on the receiving antenna signal and reducing the false alarm rate of the harmonic radar.

[0046] Specifically, if Figure 3As shown, the first RF switch unit can be a single-pole double-throw RF switch unit, recorded as a first single-pole double-throw RF switch unit, the first RF pin RF1 and the second RF pin RF2 of the first single-pole double-throw RF switch unit are respectively the first RF end and the second RF end of the first RF switch unit, which are respectively used to connect the transmitting antenna and the receiving antenna, and the RF common pin RFC1 of the first single-pole double-throw RF switch unit is the third RF end of the first RF switch unit, which is used to connect the third RF end of the second RF switch unit.

[0047] The control pin VC of the first single-pole double-throw RF switch unit is the control end of the first RF switch unit, which is used to connect the control pin (DC Control Pin) of the baseband processing unit; the power supply pin VDD of the first single-pole double-throw RF switch unit is the power supply end of the first RF switch unit, which is used to connect the preset power supply module, and the ground pin GND of the first single-pole double-throw RF switch unit is also grounded.

[0048] Continue to refer Figure 3 The second RF switch unit can also be a single-pole double-throw RF switch unit, recorded as a second single-pole double-throw RF switch unit; the first RF pin RF3 and the second RF pin RF4 of the second single-pole double-throw RF switch unit are respectively the first RF end and the second RF end of the second RF switch unit, which are respectively used to connect the transmitter circuit and the receiver circuit, and the RF common pin RFC2 of the second single-pole double-throw RF switch unit is the third RF end of the second RF switch unit, which is used to connect the third RF end of the first RF switch unit.

[0049] The control pin VC of the second single-pole double-throw RF switch unit is the control end of the second RF switch unit, which is used to connect the control pin of the baseband processing unit; the power supply pin VDD of the second single-pole double-throw RF switch unit is the power supply end of the second RF switch unit, which is used to connect the preset power supply module, and the ground pin GND of the second single-pole double-throw RF switch unit is also grounded.

[0050] A single-pole double-throw (SPDT) RF switch has a fixed terminal and two movable terminals. By switching between the fixed terminal and the two movable terminals, it achieves electrical connection between the devices connected to the fixed terminal and the movable terminals. For example, in a first SPDT RF switch unit, RFC1 is the fixed terminal, and RF1 and RF2 are the movable terminals. When RFC1 is connected to RF1, the first RF switch unit is connected to the transmitting antenna, and when RFC1 is connected to RF2, the first RF switch unit is connected to the receiving antenna. In a second SPDT RF switch unit, RFC2 is the fixed terminal, and RF3 and RF4 are the movable terminals. When RFC2 is connected to RF3, the second RF switch unit is connected to the transmitter circuit, and when RFC2 is connected to RF4, the second RF switch unit is connected to the receiver circuit.

[0051] Based on the antenna switching circuit provided in the above embodiment, an embodiment of the present application further provides a radio frequency module of a harmonic radar, such as Figure 4 As shown, the radio frequency module of the harmonic radar includes at least the antenna switching circuit, transmitter circuit, receiver circuit, transmitting antenna and receiving antenna provided in any one of the above embodiments.

[0052] Among them, the transmitting antenna and the receiving antenna are respectively connected to the first RF end and the second RF end of the first RF switch unit in the antenna switching circuit, and the transmitter circuit and the receiver circuit are respectively connected to the first RF end and the second RF end of the second RF switch unit in the antenna switching circuit.

[0053] Based on the antenna switching circuit provided in the above embodiment, Figure 5 As shown, an embodiment of the present application further provides a wireless communication module of a harmonic radar, and the wireless communication module of the harmonic radar includes at least a radio frequency module and a baseband processing unit.

[0054] The radio frequency module includes the antenna switching circuit, transmitter circuit, receiver circuit, transmitting antenna and receiving antenna provided in any of the above embodiments.

[0055] The transmitting antenna and the receiving antenna are respectively connected to the first RF terminal and the second RF terminal of the first RF switch unit in the antenna switching circuit, and the transmitter circuit and the receiver circuit are respectively connected to the first RF terminal and the second RF terminal of the second RF switch unit in the antenna switching circuit;

[0056] A first end of the baseband processing unit is connected to the control ends of the first radio frequency switch unit and the second radio frequency switch unit, and the baseband processing unit is also connected to the transmitter circuit and the receiver circuit.

[0057] The present application also provides a harmonic radar comprising at least the wireless communication module and signal processing module provided in the above-mentioned embodiments. The wireless communication module is connected to the signal processing module. Based on this connection, the signal processing module can process the second harmonic signal after the wireless communication module receives it and issue a warning. For example, when the second harmonic enters the receiver circuit through the receiving antenna, the signal processing module can confirm the presence of a nonlinear target in the harmonic radar's monitoring direction based on the second harmonic signal, thereby issuing a warning signal.

[0058] The present application also provides a radar detection device comprising at least the harmonic radar provided in the above-described embodiment. The radar detection device can use the harmonic radar provided in the above-described embodiment to monitor nonlinear targets in a monitoring direction. Furthermore, because the transmitting antenna and receiving antenna in the harmonic radar do not operate simultaneously, the signal from the transmitting antenna does not interfere with the signal from the receiving antenna during operation of the radar detection device, thereby reducing the false alarm rate of the radar detection device.

[0059] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An antenna switching circuit, characterized in that: include: a first radio frequency switch unit and a second radio frequency switch unit; The first RF end and the second RF end of the first RF switch unit are respectively used to connect the transmitting antenna and the receiving antenna of the harmonic radar, the third RF end of the first RF switch unit is connected to the third RF end of the second RF switch unit, and the first RF end and the second RF end of the second RF switch unit are respectively used to connect the transmitter circuit and the receiver circuit of the harmonic radar; The control ends of the first RF switch unit and the second RF switch unit are both used to connect to the baseband processing unit of the harmonic radar; the power ends of the first RF switch unit and the second RF switch unit are both used to connect to a preset power supply module in the harmonic radar; The first RF switch unit and the second RF switch unit are used to conduct the RF path between the transmitting antenna and the transmitter circuit when the control end is at a low level; and to conduct the RF path between the receiving antenna and the receiver circuit when the control end is at a high level.

2. The antenna switching circuit according to claim 1, wherein: The first radio frequency switch unit is a first single-pole double-throw radio frequency switch unit; The first RF pin and the second RF pin of the first single-pole double-throw RF switch unit are respectively the first RF end and the second RF end of the first RF switch unit, respectively used to connect the transmitting antenna and the receiving antenna, and the RF common pin of the first single-pole double-throw RF switch unit is the third RF end of the first RF switch unit, used to connect the third RF end of the second RF switch unit; The control pin of the first single-pole double-throw radio frequency switch unit is a control end of the first radio frequency switch unit, and is used to connect to the control pin of the baseband processing unit; The power supply pin of the first single-pole double-throw radio frequency switch unit is a power supply end of the first radio frequency switch unit, and is used to connect to the preset power supply module.

3. The antenna switching circuit according to claim 1, wherein: The second radio frequency switch unit is a second single-pole double-throw radio frequency switch unit; The first RF pin and the second RF pin of the second single-pole double-throw RF switch unit are respectively the first RF end and the second RF end of the second RF switch unit, respectively used to connect the transmitter circuit and the receiver circuit, and the RF common pin of the second single-pole double-throw RF switch unit is the third RF end of the second RF switch unit, used to connect the third RF end of the first RF switch unit; The control pin of the second single-pole double-throw radio frequency switch unit is a control end of the second radio frequency switch unit, and is used to connect to the control pin of the baseband processing unit; The power supply pin of the second single-pole double-throw radio frequency switch unit is the power supply end of the second radio frequency switch unit, which is used to connect to the preset power supply module.

4. The antenna switching circuit according to claim 2, wherein: The ground pin of the first single-pole double-throw radio frequency switch unit is also grounded.

5. The antenna switching circuit according to claim 3, wherein: The ground pin of the second single-pole double-throw radio frequency switch unit is also grounded.

6. The antenna switching circuit according to claim 1, wherein: The transmitting antenna is a 2.4 GHz antenna, and the receiving antenna is a 4.8 GHz antenna.

7. A radio frequency module for a harmonic radar, characterized in that: At least comprising: the antenna switching circuit, transmitter circuit, receiver circuit, transmitting antenna, and receiving antenna according to any one of claims 1 to 6; The transmitting antenna and the receiving antenna are respectively connected to the first RF end and the second RF end of the first RF switch unit in the antenna switching circuit, and the transmitter circuit and the receiver circuit are respectively connected to the first RF end and the second RF end of the second RF switch unit in the antenna switching circuit.

8. A wireless communication module for a harmonic radar, characterized in that: At least: RF module and baseband processing unit; The radio frequency module comprises: the antenna switching circuit, transmitter circuit, receiver circuit, transmitting antenna, and receiving antenna according to any one of claims 1 to 6; The transmitting antenna and the receiving antenna are respectively connected to the first RF terminal and the second RF terminal of the first RF switch unit in the antenna switching circuit, and the transmitter circuit and the receiver circuit are respectively connected to the first RF terminal and the second RF terminal of the second RF switch unit in the antenna switching circuit; The first end of the baseband processing unit is connected to the control ends of the first radio frequency switch unit and the second radio frequency switch unit, and the baseband processing unit is also connected to the transmitter circuit and the receiver circuit.

9. A harmonic radar, characterized in that: At least: The wireless communication module and signal processing module described in claim 8 above; the wireless communication module is connected to the signal processing module.

10. A radar detection device, characterized in that: At least: The harmonic radar according to claim 9.

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