Microwave detection module for realizing receiving and transmitting separation by using passive microstrip isolator

Abstract

The invention provides a microwave detection module for realizing receiving and transmitting separation by a passive microstrip isolator, and the passive microstrip isolator can realize receiving and transmitting separation of an antenna adopting a receiving and transmitting integrated structure design under a higher isolation degree, so that the antenna is matched with a microwave chip adopting a receiving and transmitting separation design. Therefore, the cost advantage of the corresponding microwave detection module and the miniaturization trend of a product can be guaranteed based on the matching between the antenna adopting a receiving and transmitting integrated structure design and the microwave chip adopting a receiving and transmitting separated design; and the stability and the detection precision of the microwave detection module are ensured based on receiving and transmitting separation of the antenna under relatively high isolation.

Description

Technical Field

[0001] The invention relates to the field of microwave Doppler detection, and more particularly to a microwave detection module which realizes transmission and reception separation by using a passive microstrip isolator. Background Art

[0002] With the development of Internet of Things technology, artificial intelligence, smart home, and smart security technology have more and more demands for environmental detection, especially for the detection of human presence, movement and micro-motion characteristics. Among them, microwave detection technology based on the principle of Doppler effect, as an important hub connecting people and objects, objects and objects, has unique advantages in behavior detection and existence detection technology. It can detect active objects, such as human motion characteristics, movement characteristics, and micro-motion characteristics, and even human heartbeat and breathing characteristics without infringing on human privacy, and thus has broad application prospects. Based on cost and volume considerations, the existing microwave detection module mainly adopts a transmitting and receiving antenna structure design, that is, the antenna uses the same feed port as the transmitting feed port for accessing the excitation signal and the receiving feed port for outputting the feedback signal, and at the same time serves as the transmitting antenna and receiving antenna of the microwave detection module, so as to reduce the cost and volume of the antenna and help to ensure the cost advantage of the microwave detection module and comply with the miniaturization trend of the product. Moreover, with the rapid development of the domestic chip industry and the continuous optimization of costs, the current microwave detection modules generally tend to replace the RF oscillation circuit and mixing processing circuit in the form of discrete components with microwave chips, so as to further reduce the volume of the microwave detection module while being conducive to simplifying the circuit design of the microwave detection module and enriching the functional design of the microwave detection module based on the high integration advantage of microwave chips over discrete components. However, among the current microwave chips, the microwave chips that can maintain advantages in cost, stability and isolation at the same time mainly adopt the design of separate transmission and reception, and the corresponding microwave chips use different ports as the transmission port for outputting the excitation signal and the receiving port for accessing the feedback signal.

[0003] In order to achieve the separation of transmission and reception of the antenna with a combined transmission and reception structure and match it with the microwave chip with a separate transmission and reception design, the current microwave detection module mainly corresponds to Figure 1A Use a 3dB bridge to separate the antenna's transmit and receive functions, or use the corresponding Figure 1B The ring bridge realizes the separation of antenna transmission and reception. Figure 1AAs shown, the microwave detection module includes an antenna 10P, a 3dB bridge 20P and a microwave chip 30P, wherein the antenna 10P adopts a transmitting-receiving integrated structure design and uses the same feeding port 101P as both a transmitting feeding port for receiving an excitation signal and a receiving feeding port for outputting a feedback signal, wherein the 3dB bridge 20P has an input end 201P, a first output end 202P, a second output end 203P and an isolation end 204P connected in sequence by a microstrip connecting line, and the input end 201P is connected to the isolation end 204P so that the 3dB bridge 20P is in a ring-shaped four-port form, wherein the input end 201P, the first output end 202P, the second output end 203P and the isolation end 204P are The equal impedance design corresponds to the impedance Z0, the microstrip connection line between the input end 201P and the isolation end 204P and the microstrip connection line between the first output end 202P and the second output end 203P are designed with an impedance of Z0 and have an equal length design of a quarter wavelength electrical length, the microstrip connection line between the input end 201P and the first output end 202P and the microstrip connection line between the second output end 202P and the isolation end 204P are designed with an impedance of Z0 / √2 and have an equal length design of a quarter wavelength electrical length, wherein the microwave chip 30P adopts a transmit-receive separation design and uses different ports as a transmitting port 301P for outputting an excitation signal and a receiving port 302P for receiving a feedback signal, so that in the corresponding Figure 1A In the state where the input end 201P is connected to the transmitting port 301P, the isolation end 204P is connected to the receiving port 302P, and the first output end 201P is connected to the feeding port 101P of the antenna 10P, the excitation signal output from the transmitting port 301P can be transmitted to the feeding port 101P of the antenna 10P and will not be transmitted to the receiving port 302P, while the feedback signal output from the feeding port 101P of the antenna 10P can be transmitted to the receiving port 302P, corresponding to the realization of the transmission and reception separation of the antenna 10P adopting the transmission and reception integrated structure design and matching with the microwave chip 30P adopting the transmission and reception separation design.

[0004] Based on the above description, it can be seen that the total length of the microstrip connection line of the 3dB bridge 20P, which is only connected between the four ports, is as long as one wavelength electrical length, which occupies a large area when the circuit is laid out, which is not conducive to the miniaturization of the microwave detection module. Figure 1BWhen the ring bridge shown realizes the separation of transmission and reception of the antenna 10P, since the ring bridge is structurally equivalent to extending the microstrip connection line between the first output end 202P and the second output end 203P of the 3dB bridge 20P from a quarter wavelength electrical length to a three-quarter wavelength electrical length, it will occupy a larger area when laying out the circuit board. In addition, the 3dB bridge 20P and the ring bridge are both in the form of a ring four-port, and the impedance matching between each port is complicated by the accuracy of the corresponding microstrip connection line, making it difficult to ensure the isolation between the corresponding input end and the isolation end. Therefore, in actual applications, local oscillator leakage and DC deviation are prone to occur, resulting in self-mixing, thereby deteriorating the signal-to-noise ratio. Summary of the invention

[0005] One object of the present invention is to provide a microwave detection module that realizes transmission and reception separation by a passive microstrip isolator, wherein the passive microstrip isolator can realize the transmission and reception separation of an antenna with a transmission and reception integrated structure design at a higher isolation level so as to match it with a microwave chip with a transmission and reception separation design. Therefore, based on the matching between the antenna with a transmission and reception integrated structure design and the microwave chip with a transmission and reception separation design, the cost advantage of the corresponding microwave detection module can be guaranteed and the miniaturization trend of the product can be followed. Based on the transmission and reception separation of the antenna at a higher isolation level, the stability and detection accuracy of the microwave detection module can be guaranteed.

[0006] Another object of the present invention is to provide a microwave detection module that uses a passive microstrip isolator to achieve transmission and reception separation, wherein the passive microstrip isolator adopts a three-port structure design and can simplify the impedance matching between the ports compared to the 3dB bridge and the ring bridge, and reduce the accuracy requirements of the impedance matching between the ports on the corresponding microstrip connecting lines, thereby helping to ensure the stability of the isolation between the corresponding ports, and correspondingly ensure the consistency and stability of the microwave detection module.

[0007] Another object of the present invention is to provide a microwave detection module that uses a passive microstrip isolator to achieve transmission and reception separation, wherein the passive microstrip isolator has a significantly shortened microstrip connection line length compared to a 3dB bridge and a ring bridge, thereby helping to reduce the area of ​​the circuit board layout, which is correspondingly beneficial to the further miniaturization design of the microwave detection module.

[0008] Another object of the present invention is to provide a microwave detection module that uses a passive microstrip isolator to achieve transmission and reception separation, wherein the passive microstrip isolator is configured as a Wilkinson power divider. While breaking away from the traditional application thinking of the Wilkinson power divider as a bidirectional power divider to divide one signal into two signals, or to synthesize two signals into one signal, the three-port structure design of the Wilkinson power divider and the structural characteristics of the significantly shortened microstrip connecting line length relative to the 3dB bridge and the ring bridge can be utilized to simplify the impedance matching of the passive microstrip isolator and reduce the area of ​​the circuit board layout.

[0009] Another object of the present invention is to provide a microwave detection module that realizes transmission and reception separation by a passive microstrip isolator, wherein the Wilkinson power divider is arranged between the antenna and the microwave chip in the form of a passive device, and the corresponding Wilkinson power divider, in addition to establishing an electrical connection relationship with the antenna and the microwave chip based on a corresponding circuit connection structure or circuit coupling structure, does not require an external power supply based on an additional electrical connection relationship, thereby helping to simplify the circuit layout of the passive microstrip isolator when the Wilkinson power divider is used as the passive microstrip isolator.

[0010] Another object of the present invention is to provide a microwave detection module that realizes transmission and reception separation by a passive microstrip isolator, wherein the Wilkinson power divider has a first port, a second port and a third port, and includes a first microstrip connection line connected between the first port and the second port, a second microstrip connection line connected between the first port and the third port, and a resistor connected between the second port and the third port, wherein the Wilkinson power divider is arranged between the antenna and the microwave chip in the form of a passive device, and is electrically connected to the transmission port of the microwave chip at the second port, and is electrically connected to the transmission port of the microwave chip at the first port. The first port is electrically connected to the feeding port of the antenna, and the third port is electrically connected to the receiving port of the microwave chip, so that the excitation signal output from the transmitting port of the microwave chip can be transmitted to the feeding port of the antenna and isolated from the receiving port at a higher isolation level, while the feedback signal output from the feeding port of the antenna can be transmitted to the receiving port of the microwave chip, so that the feedback signal received by the receiving port can be isolated from the excitation signal at a higher isolation level, thereby realizing the transmission and reception separation of the antenna adopting the transmission and reception integrated structure design and matching the microwave chip adopting the transmission and reception separation design.

[0011] Another object of the present invention is to provide a microwave detection module that uses a passive microstrip isolator to achieve transmission and reception separation, wherein the resistance value of the resistor of the Wilkinson power divider is set to the sum of the impedance of the second port and the impedance of the third port, thereby helping to improve the aforementioned isolation and ensure the stability and detection accuracy of the microwave detection module.

[0012] To achieve at least one of the above purposes, the present invention provides a microwave detection module that uses a passive microstrip isolator to separate transmission and reception, and the microwave detection module that uses a passive microstrip isolator to separate transmission and reception includes:

[0013] An antenna, wherein the antenna adopts a transmitting-receiving integrated structure design and uses the same feeding port as both a transmitting feeding port for receiving an excitation signal and a receiving feeding port for outputting a feedback signal;

[0014] A passive microstrip isolator, wherein the passive microstrip isolator has a first port, a second port and a third port, and includes a first microstrip connecting line connected between the first port and the second port, a second microstrip connecting line connected between the first port and the third port, and a resistor connected between the second port and the third port, wherein the sum of the line lengths of the first microstrip connecting line and the second microstrip connecting line approaches a half wavelength electrical length within a 20% error range; and

[0015] A microwave chip, wherein the microwave chip adopts a transmit-receive separation design and uses different ports as a transmitting port for outputting an excitation signal and a receiving port for receiving a feedback signal, wherein the passive microstrip isolator is arranged between the antenna and the microwave chip in the form of a passive device, and is electrically connected to the transmitting port of the microwave chip at the second port, and is electrically connected to the feeding port of the antenna at the first port, and is electrically connected to the receiving port of the microwave chip at the third port.

[0016] In one embodiment, the first microstrip connecting line and the second microstrip connecting line are designed with equal impedance.

[0017] In one embodiment, the resistance of the resistor is set to be the sum of the impedance of the second port and the impedance of the third port.

[0018] In one embodiment, the second port and the third port are designed to have equal impedance.

[0019] In one embodiment, the resistance of the resistor is set to 100Ω.

[0020] In one embodiment, the first microstrip connecting line and the second microstrip connecting line are designed with different impedances.

[0021] In one embodiment, the impedance of the first microstrip connecting line is greater than the impedance of the second microstrip connecting line.

[0022] In one embodiment, the first microstrip connection line and the second microstrip connection line are strip conductors carried on a circuit board, wherein the first microstrip connection line and the second microstrip connection line in the form of strip conductors extend from the first port respectively and define an isolation area on the circuit board with a gap between the second port and the third port as an opening, wherein the resistor is connected between the second port and the third port at the opening of the isolation area.

[0023] In one embodiment, the first microstrip connection line and the second microstrip connection line extend from the first port in opposite directions, in the same direction, and in opposite directions, respectively, and the shape of the corresponding isolation area is a rectangle.

[0024] In one embodiment, the antenna is designed as an array antenna composed of multiple antenna units, and each antenna unit adopts a transmit-receive integrated structural design, and the same feed port is used as both a transmitting feed port for receiving an excitation signal and a receiving feed port for outputting a feedback signal, wherein the feed port of each antenna unit is collectively electrically connected to the first port.

[0025] In one embodiment, the passive microstrip isolator has a feeding section extending from the first port to form an electrical connection relationship between the first port and the feeding port of the antenna based on the electrical connection relationship between the feeding section and the feeding port of the antenna, wherein the feeding section is within the isolation region.

[0026] In one embodiment, the passive microstrip isolator is provided with at least one metal sheet in the isolation region.

[0027] In one embodiment, the metal sheet is grounded.

[0028] In one embodiment, the first microstrip connecting line and the second microstrip connecting line are designed to be of equal length.

[0029] In one embodiment, the passive microstrip isolator is packaged and designed in the form of an independent component. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1A The schematic diagram is a structural diagram of an existing microwave detection module that uses a 3dB bridge to separate the antenna's transmit and receive functions.

[0031] Figure 1B It is a structural schematic diagram of an existing ring bridge.

[0032] Figure 2 The figure is a structural principle diagram of a microwave detection module according to an embodiment of the present invention.

[0033] Figure 3 is an S parameter curve between the second port and the third port of the microwave detection module according to the above embodiment of the present invention.

[0034] Figure 4 FIG. 4 is a structural principle diagram of a microwave detection module according to another embodiment of the present invention.

[0035] Figure 5 is an S parameter curve between the second port and the third port of the microwave detection module according to the above embodiment of the present invention.

[0036] Figure 6 FIG. 4 is a structural principle diagram of a microwave detection module according to another embodiment of the present invention.

[0037] Figure 7 It is a schematic diagram of a further deformed structure of a passive microstrip isolator of a microwave detection module according to another embodiment of the present invention.

[0038] Fig. 8A A schematic structural diagram of a passive microstrip isolator of a microwave detection module according to another embodiment of the present invention.

[0039] Figure 8B S parameter curve between the second port and the third port of the microwave detection module according to the above embodiment of the present invention. DETAILED DESCRIPTION

[0040] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0041] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0042] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0043] The present invention provides a microwave detection module which realizes the separation of transmission and reception by a passive microstrip isolator, wherein the passive microstrip isolator can realize the separation of transmission and reception of an antenna with a combined transmission and reception structure at a higher isolation degree so as to match it with a microwave chip with a separated transmission and reception design. Therefore, based on the matching between the antenna with a combined transmission and reception structure and the microwave chip with a separated transmission and reception design, the cost advantage of the corresponding microwave detection module and the miniaturization trend of the product can be ensured, and based on the separation of transmission and reception of the antenna at a higher isolation degree, the stability and detection accuracy of the microwave detection module can be ensured.

[0044] For example, referring to the accompanying drawings of the present invention, Figure 2As shown, the structural principle of a microwave detection module that uses a passive microstrip isolator to achieve transmission and reception separation according to an embodiment of the present invention is schematically illustrated, wherein the microwave detection module includes an antenna 10, a passive microstrip isolator 20 and a microwave chip 30, wherein the antenna 10 adopts a transmission-reception integrated structural design and uses the same feeding port 101 as a transmitting feeding port for accessing an excitation signal and a receiving feeding port for outputting a feedback signal, wherein the passive microstrip isolator 20 is configured as a Wilkinson power divider and has a first port 201, a second port 202 and a third port 203, and includes a first microstrip connecting line 21 connected between the first port 201 and the second port 202, a second microstrip connecting line 22 connected between the first port 201 and the third port 203, and a resistor 23 connected between the second port 202 and the third port 203, wherein the microwave chip 30 adopts a transmission-reception separation design and uses different ports as a transmitting port 301 for outputting an excitation signal and a receiving port 302 for accessing a feedback signal, respectively, wherein the passive microstrip isolator 20 is configured as a Wilkinson power divider and has a first port 201, a second port 202 and a third port 203. The Elkinson power divider is disposed between the antenna 10 and the microwave chip 30 in the form of a passive device, and is electrically connected to the transmitting port 301 of the microwave chip 30 at the second port 202, and is electrically connected to the feeding port 101 of the antenna 10 at the first port 201, and is electrically connected to the receiving port 302 of the microwave chip 30 at the third port 203, so that the excitation signal output from the transmitting port 301 of the microwave chip 30 can be transmitted to the feeding port 101 of the antenna 10. 1 and is isolated from the receiving port 302 of the microwave chip 30 at a higher isolation, while the feedback signal output from the feeding port 101 of the antenna 10 can be transmitted to the receiving port 302 of the microwave chip 30, so that the feedback signal received by the receiving port 302 of the microwave chip 30 can be isolated from the excitation signal at a higher isolation, so as to realize the transmission and reception separation of the antenna 10 with a transmission-reception integrated structure design at a higher isolation and match the microwave chip 30 with a transmission-reception separation design.

[0045] It is worth mentioning that, under the traditional application thinking of the Wilkinson power divider, the Wilkinson power divider is used as a bidirectional power divider to input a signal from the first port 201 and divide the signal into two signals to be outputted from the second port 202 and the third port 203, or to input a signal from the second port 202 and the third port 203 respectively and synthesize the two signals into one signal to be outputted from the first port 201. The special feature is the resistor 23 connected between the second port 202 and the third port 203, and the resistor 23 is used to suppress the imbalance between the output signals caused by the unbalanced state of the first microstrip connecting line 21 and the second microstrip connecting line 22.

[0046] That is to say, the application of the Wilkinson power divider in the microwave detection module of the present invention breaks away from the traditional application thinking of the Wilkinson power divider as a bidirectional power divider. Specifically in this embodiment of the present invention, the microwave detection module inputs an excitation signal to the second port 202 of the Wilkinson power divider so that the antenna 10 connected to the first port 201 can be transmitted and fed, and utilizes the structural feature that the sum of the line lengths of the first microstrip connection line 21 and the second microstrip connection line 22 of the Wilkinson power divider approaches the electrical length of half a wavelength, so that the excitation signal transmitted to the third port 203 sequentially through the first microstrip connection line 21 and the second microstrip connection line 22 can be anti-phase canceled with the excitation signal transmitted to the third port 203 through the resistor 23, correspondingly, the excitation signal output from the transmitting port 301 of the microwave chip 30 can be isolated from the receiving port 302 of the microwave chip 30 at a higher isolation. However, the feedback signal output from the feeding port 101 of the antenna 10 can be transmitted to the transmitting port 301 and the receiving port 302 of the microwave chip 30 via the first microstrip line 21 and the second microstrip line 22, respectively. Therefore, the feedback signal received by the receiving port 302 of the microwave chip 30 can be isolated from the excitation signal at a higher isolation, thereby achieving the transmission and reception separation of the antenna 10 with a transmission-reception integrated structure design at a higher isolation and matching the microwave chip 30 with a transmission-reception separation design.

[0047] It is worth mentioning that the sum of the line lengths of the first microstrip connecting line 21 and the second microstrip connecting line 22 of the Wilkinson power divider is close to the electrical length of half a wavelength, and the microstrip connecting line length is significantly shortened compared to the 3dB bridge and the ring bridge, which is beneficial to reducing the circuit board layout area of ​​the microwave detection module, and correspondingly is beneficial to the further miniaturization design of the microwave detection module.

[0048] In addition, the Wilkinson power divider has a three-port structure and can reduce the complexity of the impedance matching between each port being affected by the accuracy of the corresponding microstrip connecting lines compared to the 3dB bridge and the ring bridge, which correspondingly simplifies the impedance matching between each port and reduces the accuracy requirements of the impedance matching between each port on the corresponding microstrip connecting lines, thereby helping to ensure the stability of the aforementioned isolation and correspondingly ensure the consistency and stability of the microwave detection module.

[0049] Those skilled in the art should understand that the Wilkinson power divider is arranged between the antenna 10 and the microwave chip 30 in the form of a passive device. In addition to establishing an electrical connection relationship with the antenna 10 and the microwave chip 30 based on a corresponding circuit connection structure or circuit coupling structure, the Wilkinson power divider does not need an external power supply based on an additional electrical connection relationship. Therefore, it is beneficial to simplify the circuit layout of the passive microstrip isolator 20 when the Wilkinson power divider is used as the passive microstrip isolator 20.

[0050] That is to say, the Wilkinson power divider is electrically connected to the transmitting port 301 of the microwave chip 30 at the second port 202, and is electrically connected to the feeding port 101 of the antenna 10 at the first port 201, and is electrically connected to the receiving port 302 of the microwave chip 30 at the third port 203. Under the above electrical connection relationship, the description that the Wilkinson power divider is arranged between the antenna 10 and the microwave chip 30 in the form of a passive device is a restriction on the Wilkinson power divider not to be powered by an additional electrical connection relationship.

[0051] Therefore, the microwave detection module of the present invention breaks away from the traditional application thinking of the Wilkinson power divider as a bidirectional power divider, and uses the Wilkinson power divider to replace the 3dB bridge and the ring bridge as the application of the passive microstrip isolator 20. It does not require any changes to the original structural design of the Wilkinson power divider that deviate from the original structural scope of the Wilkinson power divider, nor does it require any active circuits to be added between the Wilkinson power divider and the antenna 10 and the microwave chip 30 based on additional electrical connections. This is beneficial to simplify the circuit layout of the passive microstrip isolator 20.

[0052] In this embodiment of the present invention, the first microstrip connection line 21 and the second microstrip connection line 22 are strip conductors carried on a circuit board, wherein the first microstrip connection line 21 and the second microstrip connection line 22 in the form of strip conductors extend from the first port 201 respectively and define an isolation area 200 on the circuit board with the gap between the second port 202 and the third port 203 as an opening, wherein the resistor 23 is connected between the second port 202 and the third port 203 at the opening of the isolation area 200, wherein the specific shapes of the first microstrip connection line 21 and the second microstrip connection line 22 in the form of strip conductors do not constitute a limitation to the present invention, and the corresponding shape of the isolation area 200 defined can be any shape such as a triangle, a rectangle, a rhombus, a trapezoid and a circle.

[0053] Specifically in this embodiment of the present invention, the first microstrip connection line 21 and the second microstrip connection line 22 extend from the first port 201 in opposite directions, in the same direction, and in opposite directions, respectively, and the shape of the isolation area 200 defined accordingly is a rectangle.

[0054] It is worth mentioning that since the sum of the line lengths of the first microstrip connecting line 21 and the second microstrip connecting line 22 of the Wilkinson power divider is close to the electrical length of half a wavelength and has a significantly shortened microstrip connecting line length compared to the 3dB bridge and the ring bridge, in some embodiments of the present invention, the passive microstrip isolator 20 configured as a Wilkinson power divider can also be packaged and designed in the form of an independent component, and is also beneficial to reducing the circuit board layout area of ​​the microwave detection module.

[0055] Furthermore, in this embodiment of the present invention, the first microstrip connection line 21 and the second microstrip connection line 22 are designed with equal impedance, and the first microstrip connection line 21 and the second microstrip connection line 22 corresponding to the strip conductors have the same line width, which is conducive to simplifying the impedance matching design between the Wilkinson power divider and the antenna 10 and the microwave chip 30.

[0056] In particular, within the original structure of the Wilkinson power divider, the resistance of the resistor 23 is set to the sum of the impedance of the second port 202 and the impedance of the third port 203. In order to further simplify the impedance matching design between the Wilkinson power divider and the microwave chip 30, in this embodiment of the present invention, the second port 202 and the third port 203 are designed to be equal in impedance.

[0057] In order to ensure the compatibility of the microwave detection module, in this embodiment of the present invention, the impedances of the first port 201, the second port 202 and the third port 203 are all designed to be 50Ω, and the resistance value of the corresponding resistor 23 is set to 100Ω.

[0058] Further reference is made to the accompanying drawings of the present invention. Figure 3 As shown, the S parameter curve between the second port 202 and the third port 203 of the Wilkinson power divider in this embodiment of the present invention is illustrated. Under the simulation condition that the second port 202 is connected to the excitation signal, the S parameter associated with the energy ratio of the excitation signal output by the third port 203 at the 5.8 GHz frequency point is as low as -30 dB or less, corresponding to the state in which the second port 202 of the Wilkinson power divider is electrically connected to the transmitting port 301 of the microwave chip 30, and the third port 203 is electrically connected to the receiving port 302 of the microwave chip 30. , the excitation signal output from the transmitting port 301 of the microwave chip 30 can be isolated from the receiving port 302 of the microwave chip 30 at a higher isolation degree, so that when the Wilkinson power divider is further electrically connected to the feeding port 101 of the antenna 10 at the first port 201, the feedback signal received by the receiving port 302 of the microwave chip 30 can be isolated from the excitation signal at a higher isolation degree, correspondingly realizing the transmission and reception separation of the antenna 10 with a transmission-reception integrated structure design at a higher isolation degree and matching the microwave chip 30 with a transmission-reception separation design.

[0059] It is worth mentioning that the structural feature that the first microstrip connecting line 21 and the second microstrip connecting line 22 are designed with equal impedance is neither a limitation on the original structural range of the Wilkinson power divider, nor does it constitute a structural limitation on the Wilkinson power divider serving as the passive microstrip isolator 20 in the microwave detection module of the present invention. In other embodiments of the present invention, the first microstrip connecting line 21 and the second microstrip connecting line 22 can also be designed with different impedances and have a more flexible impedance matching structure relative to the 3dB bridge and the ring bridge, which is conducive to ensuring the flexibility of the circuit layout of the passive microstrip isolator 20 and adapting to different structural and functional design requirements.

[0060] For example, referring to the accompanying drawings of the present invention, Figure 4 As shown, the structural principle of the microwave detection module according to another embodiment of the present invention is illustrated, wherein, different from the microwave detection module of the previous embodiment, in this embodiment of the present invention, the first microstrip connecting line 21 and the second microstrip connecting line 22 of the Wilkinson power divider serving as the passive microstrip isolator 20 are designed with different impedances.

[0061] Specifically in this embodiment of the present invention, the impedance of the first microstrip connecting line 21 is greater than the impedance of the second microstrip connecting line 22, and the line width of the first microstrip connecting line 21 corresponding to the strip conductor is narrower than that of the second microstrip connecting line 22. In this way, the Wilkinson power divider is electrically connected to the transmitting port 301 of the microwave chip 30 at the second port 202, and is electrically connected to the feeding port 101 of the antenna 10 at the first port 201, and is electrically connected to the receiving port 302 of the microwave chip 30 at the third port 203, so that the feedback signal output from the feeding port 101 of the antenna 10 can be transmitted to the receiving port 302 of the microwave chip 30 with a larger power division ratio, thereby improving the detection accuracy of the microwave detection module.

[0062] It is worth mentioning that, in the state where the impedance of the first microstrip connecting line 21 is greater than the impedance of the second microstrip connecting line 22, the S parameter curve between the second port 202 and the third port 203 of the Wilkinson power divider corresponds to: Figure 5 As shown, under the simulation condition that the second port 202 is connected to the excitation signal, the S parameter associated with the energy ratio of the excitation signal output by the third port 203 at the 5.8 GHz frequency point is still as low as -30 dB, and is further reduced to below -33 dB relative to the previous embodiment, corresponding to the state in which the Wilkinson power divider is electrically connected to the transmitting port 301 of the microwave chip 30 at the second port 202, and is electrically connected to the receiving port 302 of the microwave chip 30 at the third port 203, from the microwave chip 30 The excitation signal output by the transmitting port 301 can be isolated from the receiving port 302 of the microwave chip 30 at a higher isolation degree. In this way, when the Wilkinson power divider is further electrically connected to the feeding port 101 of the antenna 10 at the first port 201, the feedback signal received by the receiving port 302 of the microwave chip 30 can be isolated from the excitation signal at a higher isolation degree, thereby realizing the transmission and reception separation of the antenna 10 with a transmission-reception integrated structure design at a higher isolation degree and matching the microwave chip 30 with a transmission-reception separation design.

[0063] It can be understood that in the above-mentioned embodiments of the present invention, when the antenna 10 adopts a transmitting-receiving integrated structural design and the same feeding port 101 is used as both a transmitting feeding port for receiving an excitation signal and a receiving feeding port for outputting a feedback signal, the specific type and structure of the antenna 10 (including the number of feeding ports and the structure of the feeding ports corresponding to different feeding methods) do not constitute a limitation to the present invention.

[0064] For example, when the antenna 10 is configured as a microstrip antenna (also called a flat panel antenna), the antenna 10 has one or more feeding ports, and the same feeding port 101 serves as both a transmitting feeding port for receiving an excitation signal and a receiving feeding port for outputting a feedback signal.

[0065] That is to say, the specific type and structure of the antenna 10 do not constitute a limitation to the microwave detection module of the present invention. In the microwave detection module of the present invention, the antenna 10 can be one of many existing antennas such as a microstrip antenna, a cylindrical antenna, a dipole antenna, an inverted F antenna, an inverted L antenna, a spiral antenna, and a half-wave folded antenna. As long as the antenna 10 adopts a structure design that combines transmission and reception and uses the same feeding port 101 as both a transmitting feeding port for receiving the excitation signal and a receiving feeding port for outputting the feedback signal, it can be used.

[0066] In addition, when the antenna 10 adopts a transmitting-receiving integrated structure design and the same feeding port 101 is used as a transmitting feeding port for receiving an excitation signal and a receiving feeding port for outputting a feedback signal, the antenna 10 can also correspond to Figure 6 An array antenna is designed to be composed of multiple antenna units of the same or different types, and each of the antenna units adopts a transmit-receive integrated structural design, and the same feed port 101 is used as both a transmitting feed port for receiving an excitation signal and a receiving feed port for outputting a feedback signal, wherein the feed port 101 of each antenna unit is collectively electrically connected to the first port 201 of the Wilkinson power divider, and the corresponding antenna 10 still meets the description of "adopting a transmit-receive integrated structural design and using the same feed port 101 as both a transmitting feed port for receiving an excitation signal and a receiving feed port for outputting a feedback signal".

[0067] It is worth mentioning that in these embodiments of the present invention, the Wilkinson power divider serving as the passive microstrip isolator 20 has a feeding section 2011 extending from the first port 201, so as to form an electrical connection relationship between the first port 201 and the feeding port 101 of the antenna 10 based on the electrical connection relationship between the feeding section 2011 and the feeding port 101 of the antenna 10, and enable the impedance of the first port 201 to be differently designed based on the lead-out of the feeding section 2011 relative to the impedance of the first microstrip connection line 21 or the impedance of the second microstrip connection line 22, wherein the length of the feeding section 2011 is not included in the length of the first microstrip connection line 21 or the second microstrip connection line 22.

[0068] In particular, referring to the accompanying drawings of the present invention, Figure 7As shown, a further deformed structure of the Wilkinson power divider as the passive microstrip isolator 20 is illustrated, wherein the feeding section 2011 is within the isolation region 200, thereby facilitating further reduction of the circuit board layout area of ​​the microwave detection module, which is correspondingly facilitating further miniaturization design of the microwave detection module.

[0069] Furthermore, the Wilkinson power divider optionally corresponds to Figure 7 At least one metal sheet 24 is further disposed in the isolation region 200, so as to further improve the isolation degree based on the disposition of the metal sheet 24. The metal sheet 24 may be further grounded.

[0070] In particular, in the above-mentioned embodiments of the present invention, the first microstrip connection line 21 and the second microstrip connection line 22 are designed with equal lengths corresponding to the original structural range of the Wilkinson power divider, corresponding to the state where the sum of the line lengths of the first microstrip connection line 21 and the second microstrip connection line 22 approaches the electrical length of half a wavelength, and the line lengths of the first microstrip connection line 21 and the second microstrip connection line 22 both approach the electrical length of one-quarter a wavelength.

[0071] However, in these embodiments of the present invention, the Wilkinson power divider is used as the passive microstrip isolator 20. The Wilkinson power divider is electrically connected to the transmitting port 301 of the microwave chip 30 at the second port 202 and is electrically connected to the receiving port 302 of the microwave chip 30 at the third port 203, so that the excitation signal output from the transmitting port 301 of the microwave chip 30 can be isolated from the receiving port 302 of the microwave chip 30 at a higher isolation degree. The essential principle is to utilize The structural feature of the Wilkinson power divider in which the sum of the line lengths of the first microstrip connection line 21 and the second microstrip connection line 22 approaches the electrical length of half a wavelength enables the excitation signal transmitted to the third port 203 via the first microstrip connection line 21 and the second microstrip connection line 22 in sequence to be anti-cancelled by the excitation signal transmitted to the third port 203 via the resistor 23, thereby enabling the excitation signal output from the transmitting port 301 of the microwave chip 30 to be isolated from the receiving port 302 of the microwave chip 30 at a higher isolation level.

[0072] Therefore, in some embodiments of the present invention, the passive microstrip isolator 20 optionally breaks away from the limitation that the first microstrip connecting line 21 and the second microstrip connecting line 22 are designed to be of equal length in the original structure of the Wilkinson power divider.

[0073] That is to say, in the microwave detection module of the present invention, the understanding and definition of the structural scope of the Wilkinson power divider in the present invention allows to deviate from the limitation that the first microstrip connection line 21 and the second microstrip connection line 22 are designed to be equal in length in the original structural scope of the Wilkinson power divider. Corresponding to the structural scope in which the sum of the line lengths of the first microstrip connection line 21 and the second microstrip connection line 22 approaches the electrical length of half a wavelength, the first microstrip connection line 21 and the second microstrip connection line 22 of the microwave detection module of some embodiments of the present invention can optionally correspond to Fig. 8A The S parameter curve between the second port 202 and the third port 203 of the passive microstrip isolator 20 is designed with different lengths. Figure 8B As shown, under the simulation condition that the second port 202 is connected to the excitation signal, the S parameter associated with the energy ratio of the excitation signal output by the third port 203 at the 5.8 GHz frequency point is as low as -26 dB or less. The identification of the sum of the lengths of the first microstrip connecting line 21 and the second microstrip connecting line 22 is affected by the corresponding circuit board material and is allowed to have an error range of 20%, and the sum of the lengths of the first microstrip connecting line 21 and the second microstrip connecting line 22 is close to the electrical length of half a wavelength within the error range of 20%.

[0074] Specifically, the traditional wavelength λ and the frequency f satisfy c=λf, where c is the speed of light, and the electrical length of the wavelength is the ratio of the actual physical length of the microstrip connecting line to the wavelength of the signal transmitted on the microstrip line, wherein the wavelength of the signal transmitted on the microstrip line is affected by the electrical properties of the microstrip line itself and the environmental medium (such as the plate material of the circuit board carrying the microstrip line) and is different from the traditional wavelength λ. Correspondingly, in the microwave detection module of the present invention, when converting the actual physical length of the first microstrip connecting line 21 and the second microstrip connecting line 22 to the electrical length of the wavelength, the transmitted signal frequency f, the actual physical length L of the microstrip connecting line, and the dielectric constant ε of the plate material of the circuit board carrying the microstrip connecting line can be converted. r , the thickness of the circuit board h, the line width of the microstrip line w and the speed of light c are substituted into the formula Calculate the wavelength electrical length of the microstrip line.

[0075] Those skilled in the art will appreciate that the above embodiments are merely examples, wherein features of different embodiments may be combined with each other to obtain implementation methods that are easily conceivable based on the contents disclosed in the present invention but are not explicitly indicated in the drawings.

[0076] It should be understood by those skilled in the art that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

Claims

1. A microwave detection module that uses a passive microstrip isolator to separate transmission and reception, characterized in that: include: An antenna, wherein the antenna adopts a transmitting-receiving integrated structure design and uses the same feeding port as both a transmitting feeding port for receiving an excitation signal and a receiving feeding port for outputting a feedback signal; A passive microstrip isolator, wherein the passive microstrip isolator has a first port, a second port and a third port, and includes a first microstrip connecting line connected between the first port and the second port, a second microstrip connecting line connected between the first port and the third port, and a resistor connected between the second port and the third port, wherein the sum of the line lengths of the first microstrip connecting line and the second microstrip connecting line approaches a half wavelength electrical length within a 20% error range; as well as A microwave chip, wherein the microwave chip adopts a transmit-receive separation design and uses different ports as a transmitting port for outputting an excitation signal and a receiving port for receiving a feedback signal, wherein the passive microstrip isolator is arranged between the antenna and the microwave chip in the form of a passive device, and is electrically connected to the transmitting port of the microwave chip at the second port, and is electrically connected to the feeding port of the antenna at the first port, and is electrically connected to the receiving port of the microwave chip at the third port.

2. The microwave detection module for realizing transmission and reception separation by using a passive microstrip isolator according to claim 1, wherein the first microstrip connecting line and the second microstrip connecting line are designed with equal impedance.

3. The microwave detection module for realizing transmission and reception separation by using a passive microstrip isolator according to claim 2, wherein the resistance value of the resistor is set to the sum of the impedance of the second port and the impedance of the third port. 4 . The microwave detection module for realizing transmission and reception separation by using a passive microstrip isolator according to claim 3 , wherein the second port and the third port are designed with equal impedance. 5 . The microwave detection module for realizing transmission and reception separation by using a passive microstrip isolator according to claim 4 , wherein the resistance value of the resistor is set to 100Ω. 6 . The microwave detection module for realizing transmission and reception separation by using a passive microstrip isolator according to claim 1 , wherein the first microstrip connecting line and the second microstrip connecting line are designed with different impedances. 7 . The microwave detection module for realizing transmission and reception separation by using a passive microstrip isolator according to claim 6 , wherein the impedance of the first microstrip connecting line is greater than the impedance of the second microstrip connecting line.

8. A microwave detection module that uses a passive microstrip isolator to achieve transmission and reception separation according to any one of claims 1 to 7, wherein the first microstrip connecting line and the second microstrip connecting line are strip conductors carried on a circuit board, wherein the first microstrip connecting line and the second microstrip connecting line in the form of strip conductors respectively extend from the first port and define an isolation area on the circuit board with the gap between the second port and the third port as an opening, wherein the resistor is connected between the second port and the third port at the opening of the isolation area.

9. According to claim 8, the microwave detection module that realizes transmission and reception separation by using a passive microstrip isolator, wherein the first microstrip connecting line and the second microstrip connecting line extend from the first port in opposite directions, the same direction, and opposite directions respectively, and the shape of the correspondingly defined isolation area is a rectangle.

10. According to claim 8, a microwave detection module that uses a passive microstrip isolator to achieve transmission and reception separation, wherein the antenna is designed as an array antenna composed of multiple antenna units, and each of the antenna units adopts a transmission-reception integrated structural design and uses the same feeding port as both a transmitting feeding port for receiving an excitation signal and a receiving feeding port for outputting a feedback signal, wherein the feeding port of each antenna unit is collectively electrically connected to the first port.

11. A microwave detection module that uses a passive microstrip isolator to achieve transmission and reception separation according to claim 8, wherein the passive microstrip isolator has a feeding section extending from the first port to form an electrical connection relationship between the first port and the feeding port of the antenna based on the electrical connection relationship between the feeding section and the feeding port of the antenna, wherein the feeding section is within the isolation area. 12 . The microwave detection module for realizing transmission and reception separation by using a passive microstrip isolator according to claim 8 , wherein the passive microstrip isolator is provided with at least one metal sheet in the isolation region.

13. The microwave detection module for realizing transmission and reception separation by using a passive microstrip isolator according to claim 12, wherein the metal sheet is grounded.

14. The microwave detection module for realizing transmission and reception separation by using a passive microstrip isolator according to claim 8, wherein the first microstrip connecting line and the second microstrip connecting line are designed to be of equal length. 15 . The microwave detection module for realizing transmission and reception separation by using a passive microstrip isolator according to claim 1 , wherein the passive microstrip isolator is packaged and designed in the form of an independent component.

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