Microwave detection antenna based on single-end feed equivalent realization of differential feed

Abstract

The application provides a microwave detection antenna based on single-end feed equivalent realization of differential feed, which comprises an antenna and a coupling line coupler, wherein the coupling line coupler comprises a first coupling line and a second coupling line, the first coupling line has a first transmission section, and the second coupling line has a second transmission section; the first transmission section and the second transmission section are coupled with each other and respectively have a 1 / 4 wavelength electrical length; two ends of the first transmission section are respectively an input end and a straight-through end; two ends of the second transmission section are respectively a coupling end and an isolation end; the straight-through end and the isolation end are connected to the antenna by feed; the coupling end is grounded; in this way, a corresponding microwave excitation signal is input at the input end of the coupling line coupler based on single-end feed; the outputs of the straight-through end and the isolation end are different by 180°, so that differential feed of the antenna is realized.

Description

Technical Field

[0001] This invention relates to the field of microwave detection, and more particularly to a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent. Background Technology

[0002] With the development of IoT technology, artificial intelligence, smart homes, and smart security technologies have increasingly higher demands for the accuracy of environmental detection, especially the detection of human presence, movement, and micro-movement characteristics. Only by obtaining sufficiently stable detection results can accurate judgments be provided for smart terminal devices. Among these technologies, microwave detection technology based on the Doppler effect principle, as a crucial link between people and objects, and between objects themselves, has unique advantages in behavior and presence detection. It can detect moving objects, such as human motion characteristics, movement characteristics, and micro-movement characteristics, and even human heartbeat and breathing characteristics, without infringing on human privacy, thus having broad application prospects.

[0003] Specifically, refer to the accompanying drawings of the specification of this invention. Figures 1A to 1C A prior art microwave sounding antenna 100P employing single-end feeding is illustrated. The single-end fed microwave sounding antenna 100P includes a planar radiating source 110P and a reference ground 120P. The planar radiating source 100P has one and only one feed point 111P, wherein a corresponding radio frequency circuit is fed and connected to the feed point 111P of the planar radiating source 110P, so that the planar radiating source 110P is fed from the feed point 111P. In the state where the planar radiating source 110P is fed, corresponding to… Figure 1B and Figure 1C The single-ended fed microwave probe antenna 100P has a radiation gain of 5dB in the directional radiation direction, and the bandwidth of the S11 curve of the single-ended fed microwave probe antenna 100P is about 140MHz. It has good performance and is widely used.

[0004] However, with the rapid development of IoT technology and the rapid increase in the coverage of radio usage in adjacent or identical frequency bands, such as the increasingly widespread use of 5G wireless routers or the addition of 5G frequency bands based on duplex mode on the basis of the original 2.4G wireless routers, the problem of mutual interference between adjacent or identical frequency bands is becoming increasingly serious. This has exacerbated the signal interference, electromagnetic interference, and power loss problems generated by the single-ended fed microwave probe antenna 100P. Upgrading and improving the single-ended fed microwave probe antenna 100P to address the increasingly serious interference problem is urgent. Since external noise is usually a common-mode interference signal, the symmetry of the circuit form and the inverse phase characteristics of the signal, based on the unique circuit form of differential circuits, can effectively suppress common-mode interference signals. Specifically, differential circuits only allow differential signals to pass through, thus effectively suppressing environmental noise and electromagnetic crosstalk. (See relevant references.) Figures 2A to 2C A microwave sounding antenna 200P, improved upon the single-ended fed microwave sounding antenna 100P, is illustrated, wherein the differentially fed microwave sounding antenna 200P includes a planar radiating source 210P. A reference ground 220P is provided, wherein the planar radiation source 210P has two symmetrically designed feed points 2011P, wherein the two feed points 2011P are fed and connected to corresponding differential feed circuits, thereby enabling differential feeding of the microwave sounding antenna 200P using differential feeding. Compared with the microwave sounding antenna 100P using single-ended feeding, the microwave sounding antenna 200P using differential feeding has stronger anti-interference capability, providing an effective solution to the increasingly serious interference problem. At the same time, the corresponding bandwidth of the microwave sounding antenna 200P using differential feeding is approximately 460MHz, which reduces the precision requirements of the structure and size of the microwave sounding antenna 200P using differential feeding, making it easier to control the corresponding structural manufacturing cost, and possessing broad research and application prospects.

[0005] However, to achieve differential feeding of the antenna, a dedicated differential feeding circuit is required. Differential feeding circuits have complex circuit networks, high design difficulty and cost, and high power consumption. Furthermore, to generate differential signals, existing differential feeding circuits typically incorporate phase shifters to output differential signals by shifting the signal phase. However, because phase shifters are prone to nonlinearity with changes in the operating environment, the output signal of the differential feeding circuit is unstable. In other words, although differential feeding has significant advantages over single-ended feeding in suppressing common-mode interference, the development of differential feeding circuits limits the widespread adoption of the 200P microwave probe antenna using differential feeding. Summary of the Invention

[0006] One object of the present invention is to provide a microwave detection antenna based on single-ended feeding equivalent to differential feeding, wherein the microwave detection antenna based on single-ended feeding equivalent to differential feeding includes a coupled-line coupler and an antenna, wherein the coupled-line coupler includes a first coupled line and a second coupled line, wherein the first coupled line has a first transmission segment, and the second coupled line has a second transmission segment, wherein the first transmission segment and the second transmission segment are coupled to each other and each has a 1 / 4 wavelength electrical length, then the two ends corresponding to the first transmission segment are respectively the input end and the through end of the coupled-line coupler, and the end of the second coupled line that is the same as the input end is the antenna. The coupling end of the coupled-line coupler and the isolation end of the second transmission segment are respectively the coupling end and the isolation end of the coupled-line coupler. The coupling end and the input end are at the same end of the coupled-line coupler. The through end and the isolation end of the coupled-line coupler are fed to the antenna. The coupling end of the coupled-line coupler is grounded. In this way, the corresponding microwave excitation signal is connected to the input end of the coupled-line coupler in a single-end feeding manner. The outputs of the through end and the isolation end are about 180° out of phase, thereby realizing differential feeding of the antenna.

[0007] One object of the present invention is to provide a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent, wherein the coupling end of the coupled line coupler is grounded, and the state of the microwave excitation signal is input to the input end of the coupled line coupler in a single-ended feeding manner. The outputs of the through end and the isolation end of the coupled line coupler are approximately 180° out of phase, thereby achieving differential feeding of the antenna. This eliminates the need to design and match a dedicated differential feeding circuit specifically for differential feeding, thus overcoming the development constraints of differential feeding circuits. Without increasing the additional cost of RF circuit design, the anti-interference capability of the microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent is easily improved by differential feeding.

[0008] One object of the present invention is to provide a microwave detection antenna that achieves differential feeding based on single-ended feeding. The coupling end of the coupled line coupler is grounded, and the state of the microwave excitation signal is input to the input end of the coupled line coupler in a single-ended feeding manner. The outputs of the through end and the isolation end of the coupled line coupler are approximately 180° out of phase. In this way, differential feeding is achieved in a single-ended feeding manner, so that the existing radio frequency circuits used for single-ended feeding can be used for differential feeding. Therefore, there is no need to apply a dedicated differential feeding circuit to avoid increasing the additional circuit power consumption, which is beneficial to ensuring the low power consumption of the corresponding microwave detection module.

[0009] One object of the present invention is to provide a microwave detection antenna that achieves differential feeding based on single-ended feeding. By grounding the coupling end of the coupled line coupler, the outputs of the through end and the isolation end of the coupled line coupler are approximately 180° out of phase, thus achieving differential feeding based on single-ended feeding. This simplifies the feeding network compared to existing differential feeding solutions, avoids additional circuit power consumption, and provides a simple and easy way to achieve differential feeding.

[0010] One object of the present invention is to provide a microwave detection antenna that achieves differential feeding based on single-ended feeding. By grounding the coupling end of the coupled line coupler, differential feeding of the antenna can be achieved by outputting signals with a phase difference of approximately 180° between the through end and the isolation end of the coupled line coupler when the microwave excitation signal is input to the input end of the coupled line coupler in a single-ended feeding manner. This 180° phase difference in the antenna effectively suppresses electromagnetic interference in the environment, which exists in the form of common-mode interference in the signal. Therefore, the microwave detection antenna that achieves differential feeding based on single-ended feeding can effectively detect human movement, micro-movements, and activity characteristics corresponding to breathing and heartbeat.

[0011] One object of the present invention is to provide a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent, wherein, based on the first transmission segment and the second transmission segment having a 1 / 4 wavelength electrical length, the coupling line coupler achieves phase-differential feeding of the antenna to approximately 180°, and the isolation and impedance matching characteristics of the first and second transmission segments with a 1 / 4 wavelength electrical length simplify the impedance matching design between the radiation source and the corresponding circuit, thereby further simplifying the circuit design of the microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent.

[0012] One object of the present invention is to provide a microwave detection antenna based on single-ended feeding equivalent to differential feeding, wherein, based on the grounding of the coupling end of the coupling line coupler, electromagnetic radiation interference different from the frequency band of the microwave excitation signal can be discharged to ground through the grounding of the coupling end, thereby filtering out electromagnetic radiation interference and improving the anti-interference performance of the microwave detection antenna based on single-ended feeding equivalent to differential feeding.

[0013] One object of the present invention is to provide a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent, wherein a capacitor is electrically connected between the coupling end and the input end of the coupled line coupler, and / or a capacitor is electrically connected between the isolation end and the through end of the coupled line coupler, thereby enhancing the coupling between the first transmission segment and the second transmission segment.

[0014] According to one aspect of the present invention, a microwave detection antenna based on single-ended feeding equivalent to differential feeding is provided, wherein the microwave detection antenna based on single-ended feeding equivalent to differential feeding comprises:

[0015] One line; and

[0016] A coupled-line coupler includes a first coupled line and a second coupled line. The first coupled line has a first transmission segment, and the second coupled line has a second transmission segment. The first and second transmission segments are coupled to each other and each has a 1 / 4 wavelength electrical length. The two ends of the first transmission segment are the input and through ends of the coupled-line coupler, respectively. One end of the second transmission segment, which is the same as the input end, is the coupling end of the coupled-line coupler, and the other end is the isolation end of the coupled-line coupler. The through end and the isolation end of the coupled-line coupler are fed to the antenna. The coupling end of the coupled-line coupler is grounded. Thus, a corresponding microwave excitation signal is connected to the input end of the coupled-line coupler in a single-ended feeding manner. The outputs of the through end and the isolation end are approximately 180° out of phase, thereby achieving differential feeding of the antenna.

[0017] In one embodiment, the first coupling line and the second coupling line are carried on an antenna substrate in the form of a microstrip line structure.

[0018] In one embodiment, the first coupling line and the second coupling line are carried on the same side of the antenna substrate.

[0019] In one embodiment, the first coupling line and the second coupling line are supported oppositely on both sides of the antenna substrate in a wide-side coupling configuration.

[0020] In one embodiment, the first coupling line and the second coupling line are biasedly supported on both sides of the antenna substrate in a bias-coupled configuration.

[0021] In one embodiment, the first transmission segment and the second transmission segment are wound and carried on both sides of the antenna substrate in a combination of microstrip lines and metallized holes.

[0022] In one embodiment, the second transmission segment includes two second coupling segments, wherein the two second coupling segments are carried on the same side of the antenna substrate and electrically connected, wherein the first coupling line includes two first enhanced coupling segments extending from the input end and the through end respectively, wherein the first transmission segment is carried between the two second coupling segments, the two first enhanced coupling segments are parallel to the first transmission segment and electrically connected to the first transmission segment, wherein the two second coupling segments are located between the two first enhanced coupling segments, thereby enhancing the coupling between the first transmission segment and the second transmission segment.

[0023] In one embodiment, the first transmission segment includes two first coupling segments, wherein the two first coupling segments are carried on the same side of the antenna substrate and electrically connected, wherein the second coupling line includes two second enhanced coupling segments extending from the coupling end and the isolation end respectively, wherein the second transmission segment is carried between the two first coupling segments, and the two second enhanced coupling segments are parallel to the second transmission segment and electrically connected to the second transmission segment, wherein the two first coupling segments are located between the two second enhanced coupling segments, thereby enhancing the coupling between the first transmission segment and the second transmission segment.

[0024] In one embodiment, the antenna is configured as a planar patch antenna having a reference ground and a radiating source. The radiating source is disposed on one side of the reference ground at a distance from it. The radiating source has two feed points arranged in opposite phases, with the direction of the line connecting one feed point to the physical center point of the radiating source coinciding with the direction of the line connecting the other feed point to the physical center point of the radiating source. The through end and the isolation end of the coupling line coupler are respectively fed to the two feed points of the radiating source via a metallized via structure using a probe feeding method.

[0025] In one embodiment, the antenna is configured as a planar patch antenna having a reference ground and a radiating source, wherein the radiating source is disposed on one side of the reference ground at a distance from the reference ground, wherein the radiating source is configured in a rectangular shape, and wherein the through end and the isolation end of the coupled line coupler are fed to two adjacent corners of the radiating source in a microstrip feed manner.

[0026] In one embodiment, the microwave detection antenna based on single-ended feeding equivalent to differential feeding includes a circuit board. The antenna board has a mounting portion extending from one edge and protruding from that edge. The circuit board has a fixed through-hole penetrating both sides. The fixed through-hole has a structural configuration suitable for insertion by the mounting portion, so that the antenna board can be inserted and fixed to the circuit board with its mounting portion inserted into the fixed through-hole. In the state where the antenna board is inserted and fixed to the circuit board, the input terminal can be electrically coupled to a corresponding circuit to receive the microwave excitation signal, and the coupled terminal is grounded.

[0027] In one embodiment, the antenna includes two strip elements and a reference ground. The two strip elements are supported on the antenna substrate in a microstrip line structure. The reference ground is supported on the circuit board. The through end and the isolation end are respectively fed to one end of the two strip elements. The two ends of the coupler connected to the feed of the two strip elements are the feed terminals of the two strip elements. The two strip elements extend backward from the two feed terminals and satisfy that any point on the strip element and its corresponding feed terminal have a distance of less than or equal to 1 / 4 wavelength electrical length within a 20% error range.

[0028] In one embodiment, the antenna comprises two strip elements and a reference ground. The two strip elements are supported on the antenna substrate in a microstrip line structure and spaced apart from the reference ground. The through end and the isolation end of the coupling line coupler are respectively fed to one end of the two strip elements. The two ends of the feed connection of the two strip elements to the coupling line coupler are the feed ends of the two strip elements. The two strip elements extend from the two feed ends and have an electrical length greater than 3 / 16 and less than or equal to 5 / 16 of the wavelength. Each of the two strip elements has a coupling segment. The end of the coupling segment closest to the feed end of the strip element to which it belongs is the proximal end of the coupling segment. The two coupling segments extend from the proximal ends in opposite directions. Based on the structural characteristic that the two coupling segments of the two strip elements can couple with each other to form a common resonant frequency when they extend from the proximal ends in opposite directions, the two strip elements are arranged in opposite phases in a polarization direction that tends towards linear polarization.

[0029] In one embodiment, a coupling gap is maintained between the through end and the isolation end of the coupled line coupler and the feed end of the bar oscillator that is electrically connected to it.

[0030] In one embodiment, a capacitor is electrically connected between the through end of the coupled line coupler and the feed end of the bar oscillator connected to its feed, and / or between the isolation end of the coupled line coupler and the feed end of the bar oscillator connected to its feed.

[0031] In one embodiment, the microwave probe antenna based on single-ended feeding equivalent to differential feeding further includes a second reference ground, wherein the second reference ground is carried on the antenna substrate in the form of a metallic conductive layer and surrounds the first transmission segment and the second transmission segment.

[0032] In one embodiment, the microwave detection antenna based on single-ended feeding equivalent to differential feeding includes a circuit board, wherein a reference ground is supported on the circuit board, wherein the antenna board has an insertion portion extending from one edge and protruding from that edge, wherein the circuit board has a fixed through hole penetrating both sides therethrough, wherein the fixed through hole has a structural configuration suitable for insertion by the insertion portion, so that the antenna board can be inserted and fixed to the circuit board with its insertion portion inserted into the fixed through hole, wherein in the state where the antenna board is inserted and fixed to the circuit board, the input terminal can be electrically coupled to a corresponding circuit to receive the microwave excitation signal, and the coupled terminal is grounded.

[0033] In one embodiment, the first transmission segment and the second transmission segment are mounted on a circuit board in the form of metal pillars.

[0034] In one embodiment, the first transmission segment and the second transmission segment have rectangular cross-sections.

[0035] In one embodiment, the antenna includes two strip elements and a reference ground, wherein the reference ground is carried on the circuit board, wherein the through end and the isolation end are respectively fed to one end of the two strip elements, wherein the two ends of the feed connection of the two strip elements to the coupling line coupler are the feed ends of the two strip elements, wherein the two strip elements extend backward from the two feed ends and satisfy that any point on the strip element and its corresponding feed end have a distance of less than or equal to 1 / 4 wavelength electrical length within a 20% error range.

[0036] In one embodiment, the antenna includes two strip elements and a reference ground plane, wherein the reference ground plane is supported on the circuit board, and the through end and the isolation end of the coupling line coupler are respectively fed to one end of the two strip elements, wherein the two ends of the feed connection of the two strip elements to the coupling line coupler are the feed ends of the two strip elements, the two strip elements extend from the two feed ends and each has an electrical length greater than 3 / 16 and less than or equal to 5 / 16 of the wavelength, wherein each of the two strip elements has a coupling segment, wherein the end of the coupling segment closest to the feed end of the strip element to which it belongs is the proximal end of the coupling segment, the two coupling segments extend from the proximal ends in opposite directions, and based on the structural characteristic that the two coupling segments of the two strip elements can couple with each other to form a common resonant frequency point, the two strip elements are arranged in opposite phases in a polarization direction tending towards linear polarization.

[0037] In one embodiment, the two coupling segments of the strip oscillator extend from the proximal end in a misaligned, opposite direction.

[0038] In one embodiment, a capacitor is electrically connected between the coupling end and the input end of the coupled line coupler, and / or a capacitor is electrically connected between the isolation end and the through end of the coupled line coupler.

[0039] In one embodiment, the first transmission segment and the second transmission segment are bent.

[0040] The further objects and advantages of the invention will become fully apparent from the following description and accompanying drawings. Attached Figure Description

[0041] Figure 1A This is a schematic diagram of a microwave detection antenna using single-ended feeding, which is a prior art technology.

[0042] Figure 1B The radiation pattern of the microwave detection antenna using single-ended feeding is shown.

[0043] Figure 1C The S11 curve is for the microwave detection antenna with single-ended feeding.

[0044] Figure 2A This is a schematic diagram of a microwave detection antenna with differential feeding, which is an improvement on the single-ended feeding microwave detection antenna described above.

[0045] Figure 2B The radiation pattern of the microwave detection antenna using differential feeding is shown.

[0046] Figure 2CThe S11 curve is for the microwave detection antenna using differential feeding.

[0047] Figure 3A This is a schematic diagram of the principle of a microwave detection antenna based on single-ended feeding equivalent to differential feeding according to an embodiment of the present invention.

[0048] Figure 3B The above-described embodiment of the present invention presents a simulation curve of the principle structure of a microwave detection antenna based on single-ended feeding equivalent to differential feeding.

[0049] Figure 4A This is a schematic diagram of a modified structure of the microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0050] Figure 4B This is a schematic diagram of a modified structure of the microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0051] Figure 4C This is a schematic diagram of a modified structure of the microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0052] Figure 5A This is a schematic diagram of a coupling line coupler for a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent, according to the above embodiments of the present invention.

[0053] Figure 5B This is a schematic diagram of a coupling line coupler for a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent, according to the above embodiments of the present invention.

[0054] Figure 5C This is a schematic diagram of a coupling line coupler for a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent, according to the above embodiments of the present invention.

[0055] Figure 6A This is a schematic diagram of a coupling line coupler for a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent, according to the above embodiments of the present invention.

[0056] Figure 6B This is a schematic diagram of a coupling line coupler for a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent, according to the above embodiments of the present invention.

[0057] Figure 7A This is a schematic diagram of a coupling line coupler for a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent, according to the above embodiments of the present invention.

[0058] Figure 7B This is a schematic diagram of a coupling line coupler for a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent, according to the above embodiments of the present invention.

[0059] Figure 7C This is a schematic diagram of a coupling line coupler for a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent, according to the above embodiments of the present invention.

[0060] Figure 8A This is a schematic diagram of a modified structure of the coupling line coupler of the microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0061] Figure 8B This is a schematic diagram of a modified structure of the coupling line coupler of the microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0062] Figure 9 This is a schematic diagram of a coupling line coupler for a microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent, according to the above embodiments of the present invention.

[0063] Figure 10A A schematic diagram of a microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0064] Figure 10B A schematic diagram of a microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0065] Figure 11A A schematic diagram of a microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0066] Figure 11B A schematic diagram of a microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0067] Figure 11C A schematic diagram of a microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0068] Figure 11D A schematic diagram of a microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0069] Figure 12AA schematic diagram of a microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0070] Figure 12B A schematic diagram of a microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention.

[0071] Figure 12C A schematic diagram of a microwave detection antenna based on single-ended feeding equivalent to differential feeding according to the above embodiments of the present invention. Detailed Implementation

[0072] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0073] Those skilled in the art should understand that, in the disclosure of this invention, the terms "vertical," "horizontal," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0074] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0075] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0076] This invention provides a microwave detection antenna that achieves differential feeding based on single-ended feeding. This antenna overcomes the technical limitations of differential feeding for those skilled in the art, enabling the equivalent differential feeding effect with single-ended feeding. It suppresses environmental noise and electromagnetic interference based on the differential feeding effect, eliminating the need for specially designed and matched differential feeding circuits. This overcomes the current limitations in the development of differential feeding circuits in the industry, and improves the anti-interference capability of the microwave detection antenna based on single-ended feeding without increasing additional RF circuit design costs.

[0077] Specifically, refer to the accompanying drawings of the specification of this invention. Figure 3A The microwave detection antenna based on single-ended feeding equivalent to differential feeding includes a coupled-line coupler 10, wherein the coupled-line coupler 10 In the industry, this is generally referred to as a parallel coupled-line coupler or coupled-line coupler. The coupled-line coupler 10 includes a first coupled-line 11 and a second coupled-line 12. The first coupled-line 11 has a first transmission segment 111, and the second coupled-line 12 has a second transmission segment 121. The first transmission segment 111 and the second transmission segment 121 are coupled to each other and each has a 1 / 4 wavelength electrical length. The two ends of the first coupled-line 11 are the input terminal 101 and the through terminal 102 of the coupled-line coupler 10, respectively. The end of the second coupled-line 12 that is the same as the input terminal 101 is the coupling terminal 103 of the coupled-line coupler 10, and the other end of the second coupled-line 12 is the isolation terminal 104 of the coupled-line coupler 10. That is, the two ends of the second coupled-line 12 are the coupling terminal 103 and the isolation terminal 104 of the coupled-line coupler 10, respectively. The coupling terminal 103 and the input terminal 101 are at the same end of the coupled-line coupler 10.

[0078] Normally, when the coupled-line coupler 10 receives a corresponding signal at the input terminal 101, a portion of the current is transmitted along the first coupling section 111, and another portion of the current is coupled to the second coupling line 12 through the mutual coupling of the first transmission section 111 and the second transmission section 121. The current coupled to the second coupling line 12 by the electric field flows to the coupling terminal 103 and the isolation terminal 104 respectively, while the current coupled to the second coupling line 12 by the magnetic field flows only to the coupling terminal 103. Thus, the two currents are added in the same direction at the coupling terminal 103 and subtracted in opposite directions at the isolation terminal 104. As a result, the coupled-line coupler 10 outputs signals with a 90° phase difference at the through terminal 102 and the coupling terminal 103, and the isolation terminal 104 of the coupled-line coupler 10 is in a balanced state with no signal output.

[0079] This invention breaks through the inherent application thinking of the coupled-line coupler 10. By grounding the coupling terminal 103 of the coupled-line coupler 10, the signal originally distributed at the output of the coupling terminal 103 due to coupling is transferred to the output of the isolation terminal 104 due to the grounding of the coupling terminal 103. This breaks the balanced state of the isolation terminal 104 when the corresponding signal is connected to the input terminal 101, so that the signal voltage difference of the coupled-line coupler 10 is transferred between the through terminal 102 and the isolation terminal 104. As a result, the signal phase difference that was originally close to 90° between the through terminal 102 and the coupling terminal 103 becomes a signal phase difference that is close to 180° between the through terminal 102 and the isolation terminal 104. Thus, a signal with a phase difference of close to 180° is output between the through terminal 102 and the isolation terminal 104.

[0080] For details, please refer to the following: Figure 3B , among which based Figure 3A The schematic structure shows that a microwave excitation signal is connected to the input terminal 101 of the coupled line coupler 10 in a single-ended feeding manner. Here, m1 and m2 correspond to the signal phases of the through terminal 102 and the isolation terminal 104 at the same time, respectively. At the same time, the output phase difference between the through terminal 102 and the isolation terminal 104 tends to be 180°. In this way, based on the grounding of the coupling terminal 103 of the coupled line coupler 10, the effect of differential feeding is achieved by single-ended feeding.

[0081] Furthermore, the microwave detection antenna based on single-ended feeding equivalent to differential feeding includes an antenna, wherein the antenna is fed to the through end 102 and the isolation end 104 of the coupled-line coupler 10, and the coupling end 103 of the coupled-line coupler 10 is grounded. Thus, when the microwave excitation signal is input to the input end 101 of the coupled-line coupler 10 in a single-ended feeding manner, the outputs of the through end 102 and the isolation end 104 of the coupled-line coupler 10 are approximately 180° out of phase, thereby achieving equivalent phase difference feeding of the antenna to approximately 180° in the single-ended feeding state.

[0082] Specifically, when the coupling terminal 103 of the coupled line coupler 10 is grounded, the microwave excitation signal is input to the input terminal 101 of the coupled line coupler 10 in a single-ended feeding manner. The outputs of the through terminal 102 and the isolation terminal 104 of the coupled line coupler 10 are approximately 180° out of phase, thus achieving differential feeding of the antenna. This eliminates the need for a dedicated differential feeding circuit to be designed and matched specifically for differential feeding, thereby overcoming the development constraints of differential feeding circuits. Without increasing the additional cost of RF circuit design, the anti-interference capability of the microwave detection antenna based on single-ended feeding equivalent to differential feeding can be easily improved with differential feeding.

[0083] It is worth mentioning that by grounding the coupling terminal 103 of the coupling line coupler 10, the present invention can achieve differential feeding of the antenna in a single-ended feeding manner when the microwave excitation signal is input to the input terminal 101 of the coupling line coupler 10. This is achieved by outputting signals with a phase difference of approximately 180° between the through terminal 102 and the isolation terminal 104 of the coupling line coupler 10. This allows the use of existing radio frequency circuits applied to single-ended feeding for differential feeding, thus eliminating the need for a dedicated differential feeding circuit to avoid increasing additional circuit power consumption and ensuring low power consumption of the corresponding microwave detection module.

[0084] Specifically, the microwave excitation signal is connected to the input terminal 101 of the coupled-line coupler 10 in a single-ended feeding manner, and the coupled terminal 103 of the coupled-line coupler 10 is grounded, forming an equivalent differential-fed antenna loop. Thus, in the single-ended feeding state, the outputs of the through terminal 102 and the isolation terminal 104 of the coupled-line coupler 10 are approximately 180° out of phase, thereby achieving a phase difference feeding of the antenna of approximately 180°. This allows for differential feeding using existing single-ended feeding RF circuits, breaking through the current notion that differential feeding requires matching with a corresponding differential circuit. Compared to existing differential feeding methods, this simplifies the corresponding feeding network, thereby avoiding additional circuit power consumption and easily achieving differential feeding results. This solves the technical problem of the current industry's inability to effectively implement differential feeding.

[0085] It is worth mentioning that by grounding the coupling end 103 of the coupling line coupler 10, the antenna can be effectively differentially fed in a single-ended manner when the microwave excitation signal is input to the input end 101 of the coupling line coupler 10. This is achieved by outputting signals with a phase difference of approximately 180° between the through end 102 and the isolation end 104 of the coupling line coupler 10. This 180° phase difference in the antenna effectively suppresses electromagnetic interference in the signal as common-mode interference, thereby improving the effectiveness of the microwave detection antenna based on single-ended differential feeding in detecting human movement, micro-movements, and activity characteristics corresponding to breathing and heartbeat.

[0086] Furthermore, it is worth mentioning that, based on the fact that the first transmission segment 111 and the second transmission segment 121 have a 1 / 4 wavelength electrical length, the coupling line coupler 10, while achieving a phase difference feed of the antenna approaching 180°, also simplifies the impedance matching design between the antenna and the corresponding circuit due to the isolation and impedance matching characteristics of the first transmission segment 111 and the second transmission segment 121 with a 1 / 4 wavelength electrical length. This further simplifies the circuit design of the microwave detection antenna that achieves differential feeding based on single-ended feeding equivalent to differential feeding.

[0087] Furthermore, corresponding to Figures 4A to 4C As shown, to improve the coupling between the first transmission segment 11 and the second transmission segment 12, a capacitor C is electrically connected between the first transmission segment 111 and the second transmission segment 121 to enhance the coupling between them.

[0088] Corresponding to Figure 4A The coupling terminal 103 and the input terminal 101 of the coupled line coupler 10 are electrically connected to the capacitor C to enhance the coupling between the first transmission segment 111 and the second transmission segment 121 in a capacitor-compensated manner.

[0089] Corresponding to Figure 4B The capacitor C is electrically connected between the isolation end 104 and the through end 102 of the coupled line coupler 10, thereby enhancing the coupling between the first transmission segment 111 and the second transmission segment 121 through capacitor compensation.

[0090] Corresponding to Figure 4CThe coupling terminal 103 and the input terminal 101 of the coupled line coupler 10 are electrically connected to the capacitor C, and the isolation terminal 104 and the through terminal 102 are connected to the capacitor C, thereby enhancing the coupling between the first transmission segment 111 and the second transmission segment 121.

[0091] It is understood that the specific form of the capacitor C does not constitute a limitation of the present invention. The capacitor C can be implemented as a capacitor or as a microstrip line, and the present invention does not limit it in this regard.

[0092] Furthermore, corresponding to Figures 5A to 5C As shown, the coupled-line coupler 10 is carried on an antenna substrate 40 in a microstrip line structure. Based on the support of the antenna substrate 40 for the coupled-line coupler 10, the shape and structure of the coupled-line coupler 10 can be fixed. Furthermore, based on the increase of the dielectric constant of the dielectric environment in which the coupled-line coupler 10 is located by the antenna substrate 40, the corresponding physical size can be reduced under the limitation of the corresponding wavelength electrical length, which is beneficial to reducing the volume of the coupled-line coupler 10.

[0093] Corresponding to Figure 5A The first coupling line 11 and the second coupling line 12 are carried on the same side of the antenna substrate 40, and the first coupling line 11 and the second coupling line 12 are close to each other to ensure the coupling degree between the first coupling line 11 and the second coupling line 12.

[0094] Corresponding to Figure 5B The first coupling line 11 and the second coupling line 12 are biasedly supported on both sides of the antenna substrate 40. The first coupling line 11 and the second coupling line 12 are spaced apart by the antenna substrate 40 and have at least a portion corresponding to each other, so as to ensure the coupling degree between the first coupling line 11 and the second coupling line 12.

[0095] Corresponding to Figure 5C Preferably, the first coupling line 11 and the second coupling line 12 are supported on opposite sides of the antenna substrate 40, and the first coupling line 11 and the second coupling line 12 correspond to each other on opposite sides of the antenna substrate 40, thereby enhancing the coupling between the first coupling line 11 and the second coupling line 12, while reducing the area occupied by the first transmission segment 111 and the second transmission segment 121 in their length direction.

[0096] Furthermore, specifically corresponding to Figure 6A and Figure 6BAs shown, the coupling between the first transmission segment 111 and the second transmission segment 121 is further enhanced by bending the first transmission segment 111 and the second transmission segment 121.

[0097] Corresponding to Figure 6A The first coupling line 11 and the second coupling line 12 are carried on the same side of the antenna substrate 40. The first transmission segment 111 and the second transmission segment 121 are bent in a mirror state and have the same bending structure to enhance the coupling between the first transmission segment 111 and the second transmission segment 121. At the same time, under the length limitation of the first transmission segment 111 and the second transmission segment 121, the area occupied by the first transmission segment 111 and the second transmission segment 121 in its length direction is reduced, which is beneficial to improving the miniaturization advantage of the microwave detection antenna based on single-end feeding equivalent to differential feeding.

[0098] Corresponding to Figure 6B The first coupling line 11 and the second coupling line 12 are supported on both sides of the antenna substrate 40, and the first transmission segment 111 and the second transmission segment 121 have the same bending structure on both sides of the antenna substrate 40, so as to enhance the coupling between the first transmission segment 111 and the second transmission segment 121, while reducing the area occupied by the first transmission segment 111 and the second transmission segment 121 in the length direction based on the bending structure design.

[0099] Further, refer to Figures 7A to 7C The first coupling line 11 and the second coupling line 12 are carried on both sides of the antenna substrate 40 in a combination of microstrip lines and metallized holes, thereby improving the coupling degree between the first coupling line 11 and the second coupling line 12 based on the morphological structure design of the first coupling line 11 and the second coupling line 12.

[0100] Specifically corresponds to Figure 7A The first transmission segment 111 and the second transmission segment 121 are twisted together on both sides of the antenna substrate 40 in a combination of microstrip lines and metallized holes. The first transmission segment 111 and the second transmission segment 121 extend toward each other in staggered directions on both sides of the antenna substrate 40 to form the twisted shape of the first transmission segment 111 and the second transmission segment 121. This enhances the coupling between the first transmission segment 111 and the second transmission segment 121 and reduces the area occupied by the first transmission segment 111 and the second transmission segment 121 based on the shape design of the first transmission segment 111 and the second transmission segment 121.

[0101] Corresponding to Figure 7Band Figure 7C This involves increasing the coupling between the first coupling line 11 and the second coupling line 12 through interdigital coupling. Specifically, this corresponds to... Figure 7B The second transmission segment 121 includes two second coupling segments 1211, which are carried on the same surface of the antenna substrate 40 and electrically connected through a metallized hole structure or a jumper structure. The first coupling line 111 includes two first enhanced coupling segments 112 extending from the input end 101 and the through end 102, respectively. The first transmission segment 111 is carried between the two second coupling segments 1211. The two first enhanced coupling segments 112 are parallel to the first transmission segment 111 and electrically connected to the first transmission segment 111 through a metallized hole structure or a jumper structure. The two second coupling segments 1211 are located between the two first enhanced coupling segments 112, thus forming an interdigital coupling structure between the first coupling line 11 and the second coupling line 12. Corresponding to... Figure 7C The first transmission segment 111 includes two first coupling segments 1111, wherein the two first coupling segments 1111 are carried on the same side of the antenna substrate 40 and electrically connected through a metallized hole structure or a jumper structure. The second coupling line 121 includes two second enhanced coupling segments 122 extending from the coupling end 103 and the isolation end 104 respectively. The second transmission segment 121 is carried between the two first coupling segments 1111. The two second enhanced coupling segments 122 are parallel to the second transmission segment 121 and electrically connected to the second transmission segment 121 through a metallized hole structure or a jumper structure. The two first coupling segments 1111 are located between the two second enhanced coupling segments 122, thus forming an interdigital coupling structure between the first coupling line 11 and the second coupling line 12.

[0102] Referring to the accompanying drawings of this invention Figure 8A and Figure 8B The coupling is enhanced by cascading multiple coupling line couplers 10, based on the grounding of the coupling terminal 103 of one of the coupling line couplers 10.

[0103] Corresponding to Figure 8AThe first coupling line 11 and the second coupling line 12 of the coupled line coupler 10 are supported on both sides of the antenna substrate 40, wherein the coupling end 103 of the first-stage coupled line coupler 10 is grounded, the input end 101 of the next-stage coupled line coupler 10 is connected to the through end 102 of the previous-stage coupled line coupler 10, and the coupling end 103 of the next-stage coupled line coupler 10 is connected to the isolation end 104 of the previous-stage coupled line coupler 10, thereby forming a cascaded structure of multiple coupled line couplers 10 to enhance coupling based on the structure where the coupling end 103 of one coupled line coupler 10 is grounded.

[0104] Corresponding to Figure 8B The first coupling line 11 and the second coupling line 12 of the coupled line coupler 10 are carried on the same side of the antenna substrate 40. The coupling end 103 of the first-stage coupled line coupler 10 is grounded. The input end 101 of the next-stage coupled line coupler 10 is connected to the through end 102 of the previous-stage coupled line coupler 10. The coupling end 103 of the next-stage coupled line coupler 10 is connected to the isolation end 104 of the previous-stage coupled line coupler 10. In this way, a cascaded structure of multiple coupled line couplers 10 is realized on the same side of the antenna substrate 40.

[0105] Referring to the accompanying drawings of this invention Figure 9 As shown, the first transmission segment 111 and the second transmission segment 121 are mounted on a circuit board 50 in the form of metal pillars. The first transmission segment 111 and the second transmission segment 121 are close to each other to ensure the coupling degree of the first transmission segment 111 and the second transmission segment 121. The input terminal 101 of the coupling line coupler 10 is fixed to the circuit board 50 and electrically connected to the corresponding radio frequency circuit. The coupling terminal 103 is fixed to the circuit board 50 and grounded.

[0106] Preferably, corresponding to Figure 9The first transmission segment 111 and the second transmission segment 121 have rectangular cross-sections, such that the side of the first transmission segment 111 opposite to the second transmission segment 121 is a rectangular plane, and the side of the second transmission segment 121 opposite to the first transmission segment 111 is a rectangular plane, thereby increasing the coupling area of ​​the first transmission segment 111 and the second transmission segment 121 and enhancing the coupling degree between them. It is understood that, for the purpose of increasing the coupling area of ​​the first transmission segment 111 and the second transmission segment 121, the first transmission segment 111 and the second transmission segment 121 may also be configured with other shapes and structures, and the present invention does not limit this.

[0107] In other words, by grounding the coupling terminal 103 of the coupling line coupler 10, the present invention can achieve differential feeding of the antenna in a single-ended feeding manner when the microwave excitation signal is input to the input terminal 101 of the coupling line coupler 10. This is achieved by outputting signals with a phase difference of approximately 180° between the through terminal 102 and the isolation terminal 104 of the coupling line coupler 10. Thus, based on the phase difference feeding of the antenna with a phase difference of approximately 180°, the coupling line coupler 10 provided by the present invention is adaptable to differential feeding of antennas of various shapes to meet the requirements of differential feeding.

[0108] For example, please refer specifically to the accompanying drawings of the specification of this invention. Figure 10A The antenna is configured as a planar patch antenna and has a reference ground and a radiation source 20. The radiation source 20 is disposed on one side of the reference ground at a distance from it. The first coupling line 11 and the second coupling line 12 are carried on the same side of the antenna substrate 40. The radiation source 20 is carried on the other side of the antenna substrate 40 and has two feed points 201. The feed lines are arranged in reverse phase, with the line connecting one feed point 201 to the physical center point of the radiation source 20 coinciding with the line connecting the other feed point 201 to the physical center point of the radiation source 20. The through end 102 and the isolation end 104 of the line coupler 10 are respectively fed to the two feed points 201 of the radiation source 20 via a metallized via structure by means of probe feeding. Thus, when the line coupler 10 receives the microwave excitation signal at the input end 101 and the coupling end 103 is grounded, the through end 102 and the isolation end 104 provide a phase difference feeding of approximately 180° to the two feed points 201 of the radiation source 20.

[0109] Preferably, in this embodiment of the invention, the two feed points 201 of the radiation source 20 are arranged symmetrically about the physical center point of the radiation source 20. This allows differential feeding of the radiation source 20 in the linear polarization direction to be achieved when the two feed points 201 of the radiation source 20 are connected to signals with a phase difference of approximately 180°. This helps to balance and ensure the potential distribution intensity of the radiation source 20 in the fed state.

[0110] Further reference Figure 10B The antenna is configured as a planar patch antenna and has a reference ground and a radiation source 20. The radiation source 20 is disposed on one side of the reference ground at a distance from it. The radiation source 20, the first coupling line 11, and the second coupling line 12 are carried on the same surface of the antenna substrate 40. The through end 102 and the isolation end 104 of the coupling line coupler 10 are fed to the radiation source 20 in a microstrip feeding manner. Specifically, the radiation source 20 is configured in a rectangular shape, and the through end 102 and the isolation end 104 are respectively fed to two adjacent corners of the radiation source 20. In this way, with the microwave excitation signal input at the input end 101 of the coupling line coupler 10 and the coupling end 103 grounded, the through end 102 and the isolation end 104 of the coupling line coupler 10 output signals with a phase difference of approximately 180°, thus effectively achieving single-end feeding of the radiation source 20. Differential power supply.

[0111] Further reference is made to the accompanying drawings of this invention. Figures 11A to 11DThe radiation source 20 includes two strip-shaped dipoles 21A and a reference ground 30. The through end 102 and the isolation end 104 of the coupling line coupler 10 are respectively fed to one end of the two strip-shaped dipoles 21A. The two ends of the coupling line coupler 10 connected to the two strip-shaped dipoles 21A are the feed ends 211A of the two strip-shaped dipoles 21A. The two strip-shaped dipoles 21A extend backward from the two feed ends 211A and satisfy that any point on the strip-shaped dipole 21A has a distance of less than or equal to 1 / 4 wavelength electrical length within a 20% error range from its corresponding feed end 211A. Specifically, in these embodiments of the present invention, the feed ends 211A of the two strip-shaped dipoles 21A are directly connected to the through end 102 and the isolation end 104. The state of the isolation terminal 104 is fed to the coupling line coupler 10, with the feed terminal 211A of one of the strip oscillators 21A located at the through terminal 102, and the feed terminal 211A of the other strip oscillator 21A located at the isolation terminal 104. When the coupling line coupler 10 receives the microwave excitation signal at the input terminal 101 and is grounded at the coupling terminal 103, differential feeding is achieved for the two strip oscillators 21 at the through terminal 102 and the isolation terminal 104. One strip oscillator 21A is coupled from its feed terminal 211A along the corresponding position of the other strip oscillator 21A along the corresponding position of the other strip oscillator 21A, to form a dual coupling between the two strip oscillators 21.

[0112] It is understood that the present invention allows for a 20% error in defining the actual size of the bar oscillator 21A, that is, within a 20% error range, the distance between any point on the bar oscillator 21A and the feed terminal 211A of the bar oscillator 21A to which it belongs is less than or equal to 1 / 4 of the electrical wavelength.

[0113] Corresponding to Figure 11AThe first coupling line 11 and the second coupling line 12 are mounted on the circuit board 50 in the form of metal pillars, and the reference ground 30 is supported on the circuit board 50 in the form of a metal conductive layer. The two strip oscillators 21A extend backward from the through end 102 and the isolation end 104 of the coupling line coupler 10, respectively, and are positioned at the through end 102 and the isolation end 104. The midpoint of the connecting line is centrally symmetrically arranged, wherein the first coupling line 11 and the second coupling line 12 support the two strip dipoles 21A respectively, forming a structure in which the two strip dipoles 21A are spaced apart from the reference ground 30. The directional radiation of the microwave detection antenna based on the electromagnetic wave reflection characteristics of the reference ground 30 is formed, and the radiation gain of the microwave detection antenna based on the single-end feed equivalent differential feed in the directional radiation direction is formed. The two strip dipoles 21A are bent once, and the two bent strip dipoles 21A extend sequentially from the straight end 102 and the isolation end 104 in mutually parallel directions and in a direction perpendicular to and close to the reference ground 30, respectively.

[0114] Corresponding to Figure 11B The first coupling line 11 and the second coupling line 12 are mounted on the circuit board 50 in the form of metal pillars, and the reference ground 30 is supported on the circuit board 50 in the form of a metal conductive layer. The two strip oscillators 21A extend sequentially from the through end 102 and the isolation end 104 of the coupling line coupler 10 in opposite directions in mutually parallel misaligned directions, and in a direction perpendicular to and close to the reference ground 30.

[0115] Corresponding to Figure 11CThe first coupling line 11 and the second coupling line 12 are supported oppositely on both sides of the antenna substrate 40, the reference ground plane 30 is supported on the circuit board 50 in the form of a metal conductive layer, the antenna substrate 40 has an insertion portion 41 extending from one of its edges and protruding from that edge, and the input terminal 101 and the coupling terminal 103 of the coupling line coupler 10 are... Located in the insertion part 41, the circuit board 50 has a fixing through hole 51 extending through both sides. The fixing through hole 51 has a structure suitable for insertion by the insertion part 41, so that the antenna board 40 can be inserted and fixed to the circuit board 50 with the insertion part 41 inserted into the fixing through hole 51. In the state where the antenna board 40 is inserted and fixed to the circuit board 50, the input terminal 101 of the coupling line coupler 10 is electrically coupled to a corresponding circuit and can access the microwave excitation signal. The coupling terminal 103 of the coupling line coupler 10 is electrically connected to the reference ground 30 and is electrically connected to the reference ground. The state of surface 30 is grounded, wherein the two strip elements 21A are carried on both sides of the antenna substrate 40 in a microstrip line structure and extend sequentially from the through end 102 and the isolation end 104 of the coupling line coupler 10 in mutually parallel misaligned directions and in a direction perpendicular to the reference ground 30. Thus, based on the fact that the dielectric constant of the antenna substrate 40 is higher than that of the air environment, the actual physical size of the two strip elements 21A carried on the antenna substrate 40 is reduced under the limitation of the corresponding wavelength electrical length, thereby helping to reduce the volume of the microwave detection antenna that is equivalent to differential feeding based on single-ended feeding.

[0116] Corresponding to Figure 11D , among which based Figure 7A The first transmission segment 111 and the second transmission segment 121 of the coupled line coupler 10 shown are wound on both sides of the antenna substrate 40 in a combination of microstrip lines and metallized holes. The two strip oscillators 21A are also supported on both sides of the antenna substrate 40 in a combination of microstrip lines and metallized holes.

[0117] It is worth mentioning that, since the coupling end 103 of the coupling line coupler 10 is grounded, electromagnetic radiation interference that is different from the frequency band of the microwave excitation signal can be discharged to the ground through the grounding of the coupling end 103, thereby filtering out electromagnetic radiation interference and improving the anti-interference performance of the microwave detection antenna based on single-ended feeding equivalent to differential feeding.

[0118] Further reference is made to the accompanying drawings of this invention. Figures 12A to 12CThe antenna includes two strip elements 21B and a reference ground 30. The through end 102 and the isolation end 104 of the coupling line coupler 10 are respectively fed to one end of the two strip elements 21B. The two ends of the coupling line coupler 10 connected to the two strip elements 21B are the feed ends 211B of the two strip elements 21B. The two strip elements 21B extend from the two feed ends 211B and each has an electrical length greater than 3 / 16 and less than or equal to 5 / 16 of the wavelength. Each oscillator 21B has a coupling segment 212B, wherein the end of the coupling segment 212B closest to the feed terminal 211B of the bar oscillator 21B to which it belongs is the proximal end of the coupling segment 212B. The two coupling segments 212B extend from the proximal ends in opposite directions. Based on the structural characteristic that the two coupling segments 212B of the two bar oscillators 21B can couple with each other to form a common resonant frequency, the two bar oscillators 21B are arranged in opposite phases in a polarization direction that tends to linear polarization.

[0119] Corresponding to Figure 12A The first coupling line 11 and the second coupling line 12 are mounted on the circuit board 50 in the form of metal pillars. The reference ground 30 is supported on the circuit board 50 in the form of a metal conductive layer. The two strip oscillators 21B are mounted on the circuit board 50 via the first coupling line 11 and the second coupling line 12, respectively, to form a structure in which the two strip oscillators 21B are spaced apart from the circuit board 50. The two strip oscillators 21B extend sequentially from the two feed ends 121B at positions equidistant from the reference ground 30 in mutually parallel staggered directions, extend in a direction perpendicular to and away from the reference ground 30, extend towards each other at positions equidistant from the reference ground 30 in mutually parallel staggered directions to form the coupling segment 212B, and extend in a direction perpendicular to and close to the reference ground 30.

[0120] Corresponding to Figure 12BThe first coupling line 11 and the second coupling line 12 are mounted on the circuit board 50 in the form of metal pillars, and the reference ground 30 is supported on the circuit board 50 in the form of a metal conductive layer. In particular, the first coupling line 11 and the second coupling line 12 are bent to reduce the area occupied by the first coupling line 11 and the second coupling line 12 in their length direction. The two strip oscillators 21B extend sequentially from the two feed ends 211B at positions equidistant from the reference ground 30 in mutually parallel staggered directions, extend in a direction perpendicular to the reference ground 30, extend towards each other at positions equidistant from the reference ground 30 in mutually parallel staggered directions to form the coupling segment 212B, extend in a direction perpendicular to the reference ground 30, and extend towards each other again at positions equidistant from the reference ground 30 in mutually parallel staggered directions.

[0121] Corresponding to Figure 12C The first coupling line 11 and the second coupling line 12 are supported oppositely on both sides of the antenna substrate 40, wherein the antenna substrate 40 is fixed to the circuit substrate 50, wherein the two strip elements 21B are supported on the antenna substrate 40 in a microstrip line structure, and the two strip elements 21B extend sequentially from the two feed ends 211B at positions equidistant from the reference ground 30 in mutually parallel offset directions, extend in a direction perpendicular to the reference ground 30, extend towards each other at positions equidistant from the reference ground 30 in mutually parallel offset directions to form the coupling segment 212B, extend in a direction perpendicular to the reference ground 30, and extend towards each other again at positions equidistant from the reference ground 30 in mutually parallel offset directions.

[0122] Specifically, a coupling gap 401 is maintained between the through end 102 and the isolation end 104 of the coupled-line coupler 10 and the feed end 211B of the strip dipole 21B that is connected to its feed, thereby forming a current node between the coupled-line coupler 10 and the strip dipole 21B. This prevents the coupled-line coupler 10 from becoming part of the strip dipole 21B under the action of high-frequency current, thereby preventing the coupled-line coupler 10 and the strip dipole 21B from interfering with each other. This ensures the operational stability of the microwave detection antenna that achieves differential feeding based on single-ended feeding.

[0123] It is worth mentioning that a capacitor is electrically connected between the through end 102 of the coupled line coupler 10 and the feed end 211B of the strip dipole 21B connected to it, and / or between the isolation end 104 of the coupled line coupler 10 and the feed end 211B of the strip dipole 21B connected to it. This ensures the working performance of the microwave detection antenna based on single-ended feeding equivalent to differential feeding while forming a current node between the coupled line coupler 10 and the strip dipole 21B. Similarly, the capacitor can be implemented as a capacitor or as a microstrip line, and the present invention does not limit this.

[0124] Specifically, corresponding to Figure 12C The microwave detection antenna based on single-ended feeding equivalent differential feeding further includes a second reference ground 31, wherein the second reference ground 31 is carried on the antenna substrate 40 in the form of a metal conductive layer and surrounds the first transmission segment 111 and the second transmission segment 121 to form a shielding effect on the signals transmitted on the first coupling line 11 and the second coupling line 12, thereby preventing external interference signals from entering and improving the anti-interference performance of the microwave detection antenna based on single-ended feeding equivalent differential feeding.

[0125] It is worth mentioning that, corresponding to Figure 12C Based on the support of the antenna substrate 40 for the two strip elements 21B, the first coupling line 11, and the second coupling line 12, the shapes of the two strip elements 21B, the first coupling line 11, and the second coupling line 12 are fixed, and the positional relationship between the two strip elements 21B, the first coupling line 11, and the second coupling line 12 is fixed. Therefore, under mass production and daily use, the structure of the microwave detection antenna based on single-end feeding equivalent to differential feeding is stable and has good consistency and stability.

[0126] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and any modifications or variations of the embodiments of the present invention may be made without departing from the stated principles.

Claims

1. A microwave probe antenna based on single-ended feed equivalent realization of differential feed, characterized in that, include: One line; and A coupled-line coupler includes a first coupled line and a second coupled line. The first coupled line has a first transmission segment, and the second coupled line has a second transmission segment. The first and second transmission segments are coupled to each other and each has a 1 / 4 wavelength electrical length. The two ends of the first transmission segment are the input and through ends of the coupled-line coupler, respectively. One end of the second transmission segment, which is the same as the input end, is the coupling end of the coupled-line coupler, and the other end is the isolation end of the coupled-line coupler. The through end and the isolation end of the coupled-line coupler are fed to the antenna. The coupling end of the coupled-line coupler is grounded. Thus, a corresponding microwave excitation signal is connected to the input end of the coupled-line coupler in a single-ended feeding manner. The outputs of the through end and the isolation end are approximately 180° out of phase, thereby achieving differential feeding of the antenna.

2. The microwave detection antenna based on single-ended feeding equivalent to differential feeding as described in claim 1, wherein the first coupling line and the second coupling line are carried on an antenna substrate in a microstrip line structure.

3. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 2, wherein the first coupling line and the second coupling line are carried on the same side of the antenna substrate.

4. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 2, wherein the first coupling line and the second coupling line are supported on both sides of the antenna substrate in a wide-side coupling configuration.

5. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 2, wherein the first coupling line and the second coupling line are biasedly supported on both sides of the antenna substrate in a biased coupling configuration.

6. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 2, wherein the first transmission segment and the second transmission segment are wound and supported on both sides of the antenna substrate in a combination of microstrip lines and metallized holes.

7. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 2, wherein the second transmission segment includes two second coupling segments, wherein the two second coupling segments are carried on the same side of the antenna substrate and electrically connected, wherein the first coupling line includes two first enhanced coupling segments extending from the input end and the through end respectively, wherein the first transmission segment is carried between the two second coupling segments, the two first enhanced coupling segments are parallel to the first transmission segment and electrically connected to the first transmission segment, wherein the two second coupling segments are located between the two first enhanced coupling segments, thereby enhancing the coupling between the first transmission segment and the second transmission segment.

8. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 2, wherein the first transmission segment includes two first coupling segments, wherein the two first coupling segments are carried on the same side of the antenna substrate and electrically connected, wherein the second coupling line includes two second enhanced coupling segments extending from the coupling end and the isolation end respectively, wherein the second transmission segment is carried between the two first coupling segments, the two second enhanced coupling segments are parallel to the second transmission segment and electrically connected to the second transmission segment, wherein the two first coupling segments are located between the two second enhanced coupling segments, thereby enhancing the coupling between the first transmission segment and the second transmission segment.

9. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 3, wherein the antenna is configured as a planar patch antenna and has a reference ground and a radiation source, wherein the radiation source is disposed on one side of the reference ground in a spaced-out state, wherein the radiation source has two feed points, wherein the two feed points are arranged in opposite phases, and the direction of the line connecting one feed point to the physical center point of the radiation source coincides with the direction of the line connecting the other feed point to the physical center point of the radiation source, wherein the through end and the isolation end of the coupling line coupler are respectively fed to the two feed points of the radiation source by means of probe feeding and metallized via structure.

10. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 3, wherein the antenna is configured as a planar patch antenna and has a reference ground and a radiation source, wherein the radiation source is configured on one side of the reference ground in a spaced-out state, wherein the radiation source is configured in a rectangular shape, and wherein the through end and the isolation end of the coupling line coupler are fed and connected to two adjacent corners of the radiation source in a microstrip feeding manner.

11. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to any one of claims 2 to 8, wherein the microwave detection antenna based on single-ended feeding equivalent to differential feeding includes a circuit board, wherein the antenna board has an insertion portion extending from one of its edges and protruding from the edge, wherein the circuit board has a fixing through hole penetrating both of its surfaces, wherein the fixing through hole has a structural configuration suitable for insertion by the insertion portion, so that the antenna board can be inserted and fixed to the circuit board with its insertion portion inserted into the fixing through hole, wherein in the state where the antenna board is inserted and fixed to the circuit board, the input terminal can be electrically coupled to a corresponding circuit to receive the microwave excitation signal, and the coupling terminal is grounded.

12. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 11, wherein the antenna includes two strip elements and a reference ground, wherein the two strip elements are supported on the antenna substrate in a microstrip line structure, wherein the reference ground is supported on the circuit board, wherein the through end and the isolation end are respectively fed to one end of the two strip elements, wherein the two ends of the feed connection of the two strip elements to the coupling line coupler are the feed ends of the two strip elements, wherein the two strip elements extend backward from the two feed ends and satisfy that any point on the strip element and the feed end of the strip element to which it belongs have a distance of less than or equal to 1 / 4 wavelength electrical length within a 20% error range.

13. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to any one of claims 4 to 6, wherein the antenna has two strip elements and a reference ground, wherein the two strip elements are carried on the antenna substrate in a microstrip line structure and spaced apart from the reference ground, wherein the through end and the isolation end of the coupling line coupler are respectively fed to one end of the two strip elements, wherein the two ends of the feed connection of the two strip elements to the coupling line coupler are the feed ends of the two strip elements, and the two strip elements are fed from the two feeds. The two strip oscillators extend to each other and have an electrical length greater than or equal to 3 / 16 and less than or equal to 5 / 16 of the wavelength, respectively. Each of the two strip oscillators has a coupling segment, wherein the end of the coupling segment closest to the feed end of the strip oscillator to which it belongs is the proximal end of the coupling segment. The two coupling segments extend from the proximal ends in opposite directions. Based on the structural characteristic that the two coupling segments of the two strip oscillators can couple with each other to form a common resonant frequency due to their extension from the proximal ends in opposite directions, the two strip oscillators are arranged in opposite phases in a polarization direction that tends to linear polarization.

14. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 13, wherein a coupling gap is maintained between the through end and the isolation end of the coupled line coupler and the feeding end of the strip vibrator connected to its feed.

15. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 14, wherein a capacitor is electrically connected between the through end of the coupled line coupler and the feed end of the strip vibrator connected to it, and / or between the isolation end of the coupled line coupler and the feed end of the strip vibrator connected to it.

16. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 13, wherein the microwave detection antenna based on single-ended feeding equivalent to differential feeding further includes a second reference ground, wherein the second reference ground is carried on the antenna substrate in the form of a metal conductive layer and surrounds the first transmission segment and the second transmission segment.

17. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 13, wherein the microwave detection antenna based on single-ended feeding equivalent to differential feeding includes a circuit board, wherein the reference ground is supported on the circuit board, wherein the antenna board has an insertion portion extending from one edge and protruding from the edge, wherein the circuit board has a fixed through hole penetrating both sides therethrough, wherein the fixed through hole has a structural configuration suitable for insertion by the insertion portion, so that the antenna board can be inserted and fixed to the circuit board with its insertion portion inserted into the fixed through hole, wherein in the state where the antenna board is inserted and fixed to the circuit board, the input terminal can be electrically coupled to a corresponding circuit to receive the microwave excitation signal, and the coupling terminal is grounded.

18. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 1, wherein the first transmission segment and the second transmission segment are mounted on a circuit board in the form of a metal columnar structure.

19. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 18, wherein the first transmission segment and the second transmission segment have rectangular cross-sections.

20. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 19, wherein the antenna includes two strip elements and a reference ground, wherein the reference ground is carried on the circuit board, wherein the through end and the isolation end are respectively fed to one end of the two strip elements, wherein the two ends of the feed connection of the two strip elements to the coupling line coupler are the feed ends of the two strip elements, wherein the two strip elements extend backward from the two feed ends and satisfy that any point on the strip element and the feed end of the strip element to which it belongs have a distance of less than or equal to 1 / 4 wavelength electrical length within a 20% error range.

21. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 19, wherein the antenna includes two strip elements and a reference ground, wherein the reference ground is supported on the circuit board, wherein the through end and the isolation end of the coupling line coupler are respectively fed to one end of the two strip elements, wherein the two ends of the feed connection of the two strip elements to the coupling line coupler are the feed ends of the two strip elements, and the two strip elements extend from the two feed ends and respectively have a greater than The electrical length is equal to 3 / 16 and less than or equal to 5 / 16 of the wavelength, wherein each of the two strip oscillators has a coupling segment, wherein the end of the coupling segment closest to the feed end of the strip oscillator to which it belongs is the proximal end of the coupling segment, and the two coupling segments extend from the proximal end in opposite directions, so as to form a common resonant frequency by mutual coupling based on the structural characteristic that the two coupling segments of the two strip oscillators can extend from the proximal end in opposite directions. This results in a structural state in which the two strip oscillators are arranged in opposite phases in a polarization direction that tends to linear polarization.

22. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 21, wherein the two coupling segments of the strip vibrator extend from the near end in a misaligned opposite direction.

23. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 1, wherein a capacitor is electrically connected between the coupling end and the input end of the coupled line coupler, and / or a capacitor is electrically connected between the isolation end and the through end of the coupled line coupler.

24. The microwave detection antenna based on single-ended feeding equivalent to differential feeding according to claim 1, wherein the first transmission segment and the second transmission segment are bent.

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