A radio frequency radar structure, circuit and its control method for enhancing induction sensitivity

Abstract

The present invention provides a radio frequency radar structure, circuit and control method for enhancing induction sensitivity. An induction radar module is arranged in a reflection resonant cavity space formed by a non-metallic material housing and a metal base. The induction radar module at least includes: a connector with adjustable height, a radar PCBA and a power control PCBA; a radar antenna module is arranged on the upper surface of the radar PCBA, and a variable pattern metasurface flexible conformal passive resonant antenna is arranged at a preset distance from the upper surface of the radar PCBA. By organically combining the variable pattern metasurface flexible conformal passive resonant antenna with the radio frequency induction radar, the induction radar device can obtain a larger induction radius with a smaller radio frequency transmission power, realizing high-sensitivity induction detection of the induction area; and the flexible conformal characteristic enables it to be bonded and combined with a housing of any shape, not only maintaining the beauty of the non-metallic material housing, but also directly facing the external induction detection area, facilitating sensitive induction and identification.

Description

Technical Field

[0001] The present invention relates to an inductive radar device, in particular to a radio frequency radar structure, circuit and its control method for enhancing inductive sensitivity. Background Art

[0002] In the field of automatic induction and control applications, inductive sensors are commonly used, such as inductive radars, infrared optical ranging, and pyroelectric infrared induction of the human body. Among them, inductive radars are increasingly used due to their small size, adjustable operating distance, and fast response speed. They are more and more applied in the field of intelligent control, such as intelligent toilet operation, lighting control, intelligent household appliances, etc. Especially in lighting control, it provides a good solution for the convenience of life. Generally, most inductive radars use rectangular microstrip antennas or array microstrip antennas, and basically no control measures are taken for the radiation of radio waves in the front lobe and back lobe. Only an expedient adjustment is made by adjusting the trigger threshold to meet the basic usage requirements. However, due to complex environmental space layouts and factors such as background noise interference, inductive radars, especially those integrated inside lamps, generally work by increasing the transmission power (3 - 16 dBm) and reducing the recognition threshold of received signals in order to penetrate the housing structure and receive reflected signals simultaneously, resulting in a series of induction problems such as false operations (false alarms) or missed detections. Summary of the Invention

[0003] In view of the above technical problems, the present invention proposes a radio frequency radar structure, circuit and its control method for enhancing inductive sensitivity. Based on the microstrip antenna radar, by supplementing with a variable pattern metasurface flexible passive resonant conformal antenna, the radar can achieve accurate induction and control of a controllable distance and range under the state of as small as possible transmission power and power consumption, avoiding a series of problems such as interference, false triggering, mutual interference, and high power consumption caused by simply increasing the transmission power, and truly achieving convenient life and energy conservation and consumption reduction.

[0004] Specifically, a radio frequency radar structure for enhancing inductive sensitivity includes:

[0005] A reflection resonant cavity space formed by a non-metallic material housing and a metal base supporting a power supply control PCBA;

[0006] An inductive radar module is arranged in the reflection resonant cavity space, and the inductive radar module at least includes:

[0007] A connector with adjustable height, and a radar PCBA and the power supply control PCBA respectively fixed on the upper and lower surfaces of the connector; the other side of the power supply control PCBA is fixed on the metal base;

[0008] The lower surface of the radar PCBA is adhesively fixed to the connector, and a radar antenna module is provided on the upper surface. A variable-pattern metasurface flexible passive resonant conformal antenna is provided at a preset distance from the upper surface of the radar PCBA.

[0009] Among them, the adjustable height of the adjustable connector is 1 / 4 to 1 / 2 of the radar operating wavelength, so that the distance between the radar PCBA and the variable-pattern metasurface flexible passive resonant conformal antenna can be adjusted within the reflection resonant cavity space. Especially after the power control PCBA is fixed on the metal base, the requirement of the preset distance is met.

[0010] The variable-pattern metasurface flexible passive resonant conformal antenna is arranged on the inner surface of the non-metallic material shell, or adhesively combined with the non-metallic material shell, or spaced from the non-metallic material shell by a preset distance.

[0011] The variable-pattern metasurface flexible passive resonant conformal antenna at least includes: a transparent adhesive, a flexible substrate layer, a variable metal pattern layer and a surface protection cover layer laminated in sequence.

[0012] The flexible substrate layer is for the variable-pattern metasurface flexible passive resonant conformal antenna to fit the non-metallic material shell to meet the conformal requirement; after conformal shaping, the variable-pattern metasurface flexible passive resonant conformal antenna is not only beautiful but also directly faces the external induction detection area, facilitating sensitive induction and recognition.

[0013] Furthermore, the variable-pattern metasurface flexible passive resonant conformal antenna further includes: microstrip patches arranged in a periodic pattern according to a specific rule inside the variable metal pattern layer, and the microstrip patches have specific text and pattern structures; the specific text and pattern are at least any one or several of characters, rectangles, circles and Vs.

[0014] Furthermore, the radar antenna module at least includes: a radar chip arranged on the radar PCBA, and Tx microstrip antennas and Rx microstrip antennas of equal size arranged symmetrically on both sides of the radar chip; the radar chip is connected to the Tx microstrip antenna and the Rx microstrip antenna through a Tx port and an Rx port respectively through coupling feed lines. The radar antenna module uses an X-band radar chip of 9.85 GHz or 10.525 GHz.

[0015] The long side and the wide side of the variable-pattern metasurface flexible passive resonant conformal antenna respectively have a corresponding ratio of 1:1.2 to 1.8 with the long side and the wide side of the Tx microstrip antenna and the Rx microstrip antenna. The preset distance between the Tx microstrip antenna and the Rx microstrip antenna and the variable-pattern metasurface flexible passive resonant conformal antenna is 1 / 32 to 1 / 4 of the radar operating wavelength. The variable-pattern metasurface flexible passive resonant conformal antenna is at least a planar or curved surface structure.

[0016] One end of the power control PCBA is connected to the load circuit, and the other end is connected to the DC power supply.

[0017] The overall power consumption of the radio frequency radar structure with enhanced induction sensitivity is <0.1W.

[0018] A radio frequency radar circuit with enhanced induction sensitivity at least includes: a radio frequency radar structure with enhanced induction sensitivity, a radio frequency radar structure with enhanced induction sensitivity, and a load circuit connected in series with the radio frequency radar structure; the load circuit is at least a one-way or multi-way parallel circuit; and a DC power supply connected to the radio frequency radar structure, and the radio frequency radar structure at least includes:

[0019] A connector with adjustable height, and a radar PCBA and a power control PCBA respectively fixed on the upper and lower surfaces of the connector; the other surface of the power control PCBA is fixed on the metal base;

[0020] The lower surface of the radar PCBA is adhesively fixed to the connector, and a radar antenna module is arranged on the upper surface. A variable-pattern metasurface flexible passive resonant conformal antenna is arranged at a preset distance from the upper surface of the radar PCBA;

[0021] The radar antenna module at least includes: a radar chip arranged on the radar PCBA, and a Tx microstrip antenna and an Rx microstrip antenna of equal size arranged on both symmetric sides of the radar chip; the radar chip is connected to the Tx microstrip antenna and the Rx microstrip antenna respectively through the Tx port and the Rx port through coupling feed lines.

[0022] Furthermore, the variable pattern metasurface flexible passive resonant conformal antenna at least includes: a transparent backing glue, a flexible substrate layer, a variable metal pattern layer and a surface protection covering layer laminated together in sequence; the variable pattern metasurface flexible passive resonant conformal antenna also includes: microstrip patches arranged periodically according to a specific rule and arranged inside the variable metal pattern layer, and the microstrip patches have a specific text and pattern structure; the specific text and pattern are at least any one or more of characters, rectangles, circles and V-shapes; the long side and wide side of the variable pattern metasurface flexible passive resonant conformal antenna correspond to the long side and wide side of the Tx microstrip antenna and the Rx microstrip antenna in a ratio of 1:1.2 to 1.8.

[0023] Metasurface materials are usually composed of periodic arrangements of subwavelength microstructure units, allowing the irradiation direction of electromagnetic waves to be perpendicular to the plane of the material. Electromagnetic metasurfaces have properties similar to ideal magnetic conductors that can reflect plane waves in phase within a specific frequency range. In addition, the amplitude, phase, polarization mode, and propagation mode of electromagnetic waves can be flexibly and effectively controlled. After the radar signal passes through the variable pattern metasurface flexible passive resonant conformal antenna, the shape characteristics of the signal such as amplitude and phase will be shaped, and the signal gain will be further improved; the reflected radar signal will also increase the gain when passing through the variable pattern metasurface flexible passive resonant conformal antenna.

[0024] Preferably, the present invention provides a radio frequency radar control method for enhancing sensing sensitivity, comprising at least:

[0025] S1: Through a retractable height-adjustable connector, the distance between the variable pattern metasurface flexible passive resonant conformal antenna and the Tx microstrip antenna of the radar antenna module is adjusted to form a resonant cavity;

[0026] S2: The Tx microstrip antenna of the radar antenna module transmits high-frequency electromagnetic waves at a preset frequency, which are repeatedly reflected and coupled by the variable pattern metasurface flexible passive resonant conformal antenna in the resonant cavity and then transmitted to the external sensing detection area;

[0027] S3: When an active or slightly moving target appears within the sensing detection area, the variable pattern metasurface flexible passive resonant conformal antenna receives the reflected wave of the active or slightly moving target, and then transmits it to the Rx microstrip antenna of the radar antenna module through the resonant cavity;

[0028] S4: The radar antenna module performs dual threshold control logic according to the reflected wave and outputs a preset control instruction.

[0029] The dual-threshold control logic can output different control instructions according to the activity or micro-motion of the target, thereby controlling the load circuit more precisely.

[0030] The beneficial effects of the present invention are as follows. By organically combining the variable-pattern metasurface flexible passive resonant conformal antenna with the inductive radar, the variable-pattern metasurface flexible passive resonant conformal antenna is utilized to enhance the gain during the transmission and reception of radar signals, enabling the inductive radar to achieve stronger gain and shaping with a relatively low RF transmission power, realizing high-sensitivity inductive control in the monitored area. At the same time, it reduces its own radiation interference and suppresses external radiation interference. The flexible conformal characteristic facilitates the installation of the variable-pattern metasurface flexible passive resonant conformal antenna on the non-metallic material housing. It can conform to the non-metallic material housing, not only maintaining the aesthetics of the non-metallic material housing but also directly facing the radar monitoring space, facilitating sensitive inductive identification. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a side view of a radio frequency radar structure for enhancing inductive sensitivity according to the present invention.

[0032] Figure 2 It is a schematic diagram of a radar antenna module of a radio frequency radar structure for enhancing inductive sensitivity according to the present invention.

[0033] Figure 3 It is a schematic diagram of a variable-pattern metasurface flexible passive resonant conformal antenna of a radio frequency radar structure for enhancing inductive sensitivity according to the present invention.

[0034] Figure 4 It is a schematic diagram of a microstrip patch of a radio frequency radar structure for enhancing inductive sensitivity according to the present invention.

[0035] Figure 5 It is a side view of a radio frequency radar circuit for enhancing inductive sensitivity according to the present invention.

[0036] Wherein: 101 - non-metallic material housing; 102 - metal base; 103 - reflection resonant cavity space; 104 - load circuit; 105 - DC power supply; 201 - connector; 202 - power control PCBA; 203 - radar PCBA; 210 - radar antenna module; 211 - radar chip; 212 - Tx microstrip antenna; 213 - Rx microstrip antenna; 300 - variable-pattern metasurface flexible passive resonant conformal antenna; 301 - transparent adhesive; 302 - flexible substrate layer; 303 - variable metal pattern layer; 304 - surface protection coating. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] To enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0038] Specifically, as Figure 1 shown, a radio frequency radar structure for enhancing induction sensitivity mainly includes:

[0039] A reflection resonant cavity space formed by a non-metallic material housing and a metal base supporting a power control PCBA;

[0040] And an induction radar module is arranged in the reflection resonant cavity space, and the induction radar module at least includes:

[0041] A connector with adjustable height, and a radar PCBA and the power control PCBA respectively fixed on the upper and lower surfaces of the connector; the other surface of the power control PCBA is fixed on the metal base; and the lower surface of the radar PCBA is adhesively fixed to the connector, and a radar antenna module is arranged on the upper surface, and a variable pattern metasurface flexible passive resonant conformal antenna is arranged at a preset distance from the upper surface of the radar PCBA. Among them, the adjustable height of the connector is 1 / 4 to 1 / 2 of the radar operating wavelength, so that the distance between the radar PCBA and the variable pattern metasurface flexible passive resonant conformal antenna can be adjusted in the reflection resonant cavity space, especially after the power control PCBA is fixed on the metal base, to meet the requirement of the preset distance.

[0042] In addition, the lower surface of the radar PCBA is adhesively fixed to the connector, and a radar antenna module is arranged on the upper surface; the radar antenna module, as Figure 2 shown, at least includes: a radar chip arranged on the radar PCBA, and Tx microstrip antennas and Rx microstrip antennas of equal size arranged on both sides of the radar chip symmetrically; the radar chip is connected to the Tx microstrip antenna and the Rx microstrip antenna respectively through a Tx port and an Rx port through coupling feeders. The radar antenna module uses an X-band radar chip of 9.85 GHz or 10.525 GHz.

[0043] A variable pattern metasurface flexible passive resonant conformal antenna is arranged at a preset distance from the upper surface of the radar PCBA. The variable pattern metasurface flexible passive resonant conformal antenna is arranged on the inner surface of the non-metallic material housing, or is attached to the non-metallic material housing, or is spaced from the non-metallic material housing by a preset distance.

[0044] Metasurfaces are usually composed of periodically arranged sub-wavelength microstructure units, allowing the incident direction of electromagnetic waves to be perpendicular to the material plane. Electromagnetic metasurfaces have the property of enabling in-phase reflection of plane waves by an ideal magnetic conductor within a specific frequency range. In addition, they can also flexibly and effectively control the characteristics of electromagnetic waves such as amplitude, phase, polarization mode, and propagation mode, and have a wide range of applications in the research of high-performance antennas, improvement of array antenna performance, reduction of radar cross-section, and microwave transmission, etc.

[0045] After the signal transmitted by the radar passes through the variable-pattern metasurface flexible passive resonant conformal antenna, the shape characteristics such as the amplitude and phase of the signal will be shaped, and the signal gain will be further enhanced; when the shaped radar signal is reflected by the human body and then passes through the variable-pattern metasurface flexible passive resonant conformal antenna, the gain will also be increased. In this way, the induction radar uses a relatively small radio frequency transmission power and a low-sensitivity power device to achieve high-sensitivity induction control of the monitoring area. At the same time, most of the external interfering electromagnetic signals will be reflected by the variable-pattern metasurface flexible passive resonant conformal antenna, which can reduce the interference caused by external electromagnetic signals.

[0046] As Figure 3 shown, the variable-pattern metasurface flexible passive resonant conformal antenna at least includes: a transparent adhesive, a flexible substrate layer, a variable metal pattern layer, and a surface protection cover layer laminated in sequence. The flexible substrate layer is for the variable-pattern metasurface flexible passive resonant conformal antenna to conform to the non-metallic material shell to meet the conformal requirements; after conformal shaping, the variable-pattern metasurface flexible passive resonant conformal antenna is not only beautiful but also directly faces the external induction detection area, facilitating sensitive induction and identification.

[0047] Furthermore, the variable-pattern metasurface flexible passive resonant conformal antenna further includes: microstrip patches arranged in a periodic pattern according to a specific rule inside the variable metal pattern layer. As Figure 4 shown, the microstrip patches have specific text and pattern structures; the specific text and pattern are at least any one or several of characters, rectangles, circles, and Vs.

[0048] The long sides and short sides of the variable-pattern metasurface flexible passive resonant conformal antenna correspond to the long sides and short sides of the Tx microstrip antenna and the Rx microstrip antenna in a ratio of 1:1.2 to 1.8 respectively. The preset distance between the Tx microstrip antenna and the Rx microstrip antenna and the variable-pattern metasurface flexible passive resonant conformal antenna is 1 / 32 to 1 / 4 of the radar operating wavelength, and the variable-pattern metasurface flexible passive resonant conformal antenna is at least a planar or curved surface structure.

[0049] One end of the power control PCBA is connected to the load circuit, and the other end is connected to the DC power supply.

[0050] The overall power consumption of the radio frequency radar structure with enhanced induction sensitivity is < 0.1W.

[0051] Preferably, the present invention also provides a radio frequency radar circuit with enhanced induction sensitivity, as Figure 5 shown, at least including: a radio frequency radar structure with enhanced induction sensitivity, and a load circuit connected in series with the radio frequency radar structure; wherein, the load circuit is at least one or multiple parallel circuits; and a DC power supply connected to the radio frequency radar structure, which can be widely applied to multiple fields, such as lighting induction field, automotive radar field, and smart home appliance field, etc.

[0052] Among them, in this embodiment, it is a lighting fixture, and the radio frequency radar structure with enhanced induction sensitivity at least includes:

[0053] The non-metallic material shell can be a light-transmitting lamp cover, such as a transparent acrylic lamp cover; the metal base can be an aluminum alloy base, which is lightweight and easy to install. The light-transmitting lamp cover and the aluminum alloy base form a reflection resonant cavity space; further, the aluminum alloy base can be designed in an "H" shape, and there are 2 inward buckles above the "H" shape of the aluminum alloy base; the light-transmitting lamp cover can be designed in an inverted "convex" shape, and the bottom of the inverted "convex" shape is the opening of the light-transmitting lamp cover, and there is an outward protrusion at the edge of the opening. The buckle and the protrusion are tightly combined to form a reflection resonant cavity space.

[0054] The load circuit can be 1 LED light source, or multiple LED light sources in parallel, and is connected to the radio frequency radar structure with enhanced induction sensitivity.

[0055] A retractable and adjustable-height connector, and a radar PCBA and a power control PCBA respectively fixed on the upper and lower surfaces of the connector; wherein, the other side of the power control PCBA is fixed on the metal base. The adjustable height of the connector is 1 / 4 to 1 / 2 of the radar working wavelength, so that the distance between the radar PCBA and the variable pattern metasurface flexible passive resonant conformal antenna can be adjusted in the reflection resonant cavity space, especially after the power control PCBA is fixed on the metal base, to meet the requirements of the preset distance.

[0056] The lower surface of the radar PCBA is adhesively fixed to the connector, and a radar antenna module is arranged on the upper surface. A variable pattern metasurface flexible passive resonant conformal antenna is arranged at a preset distance from the upper surface of the radar PCBA; the central axes of the adjustable connector, the power control PCBA, and the radar PCBA all coincide with the central axis of the reflection resonant cavity space.

[0057] The radar antenna module at least includes: a radar chip arranged on the radar PCBA, and a Tx microstrip antenna and an Rx microstrip antenna that are arranged on both sides of the radar chip symmetrically and are equal in size; the radar chip is connected to the Tx microstrip antenna and the Rx microstrip antenna respectively through a Tx port and an Rx port through a coupling feeder.

[0058] Furthermore, the variable pattern metasurface flexible passive resonant conformal antenna is laminated in sequence by transparent adhesive, flexible substrate layer, variable metal pattern layer and surface protection cover layer; it also includes microstrip patches arranged periodically according to a specific rule and arranged inside the variable metal pattern layer, and the microstrip patches have specific text and pattern structures; the specific text and pattern are at least any one or more of characters, rectangles, circles and V-shapes; the long side and wide side of the variable pattern metasurface flexible passive resonant conformal antenna correspond to the long side and wide side of the Tx microstrip antenna and the Rx microstrip antenna in a ratio of 1:1.2 to 1.8. The preset distance between the Tx microstrip antenna and the Rx microstrip antenna and the variable pattern metasurface flexible passive resonant conformal antenna is 1 / 32 to 1 / 4 of the radar operating wavelength. In this way, the area of the variable pattern metasurface flexible passive resonant conformal antenna is larger than the area of the Tx microstrip antenna or the Rx microstrip antenna, ensuring that the transmitted radar signal can fully pass through the variable pattern metasurface flexible passive resonant conformal antenna without being reflected by the transparent lampshade.

[0059] Preferably, the present invention provides a radio frequency radar control method for enhancing sensing sensitivity, comprising at least:

[0060] S1: adjusting the distance between the variable pattern metasurface flexible passive resonant conformal antenna and the Tx microstrip antenna of the radar antenna module through the connector to form a resonant cavity;

[0061] S2: The Tx microstrip antenna of the radar antenna module emits high-frequency electromagnetic waves at a preset period, passes through the resonant cavity, and is coupled and enhanced by the variable pattern metasurface flexible passive resonant conformal antenna and then emitted to the external sensing detection area;

[0062] S3: When an active or slightly moving target appears within the sensing detection area, the variable pattern metasurface flexible passive resonant conformal antenna receives the reflected wave of the active or slightly moving target, and then transmits it to the Rx microstrip antenna of the radar antenna module through the resonant cavity;

[0063] S4: The radar antenna module performs dual threshold control logic according to the reflected wave and outputs a preset control instruction.

[0064] The dual threshold control logic specifically refers to:

[0065] S41: The radar antenna module determines whether there is a moving target based on the reflection information within the range of the external induction detection area. If the moving target test value is greater than or equal to the first program threshold, it is determined that there is a moving target, and a high level is output at the port connecting the load circuit. At the same time, the moving target detection threshold is adjusted to the second program threshold, and S42 is entered; otherwise, if there is no moving target, it goes to S43;

[0066] S42: Start the micro-motion detection program to determine whether the micro-moving target persists. If the micro-moving target test value is greater than the second program threshold, it is determined that there is a persistent micro-moving target, and the port connecting the load circuit continuously outputs a high level; otherwise, if there is no micro-moving target, it goes to S43;

[0067] S43: The port connecting the load circuit outputs a low level, and at the same time, the second program threshold is restored to the first program threshold.

[0068] When the radio frequency radar structure of the lighting fixture in this embodiment senses that a human body approaches the external induction detection area, one or more groups of light sources are started to illuminate the preset area; if the human body has micro-motions, such as upper limb movements like makeup or lower limb movements like walking, the light source of the lighting fixture is kept continuously emitting light; it is not until the radio frequency radar structure senses that there is no micro-motion that the light source is turned off.

[0069] The beneficial effects of the present invention are as follows: By organically combining the variable-pattern metasurface flexible passive resonant conformal antenna with the induction radar, the effect of enhancing the gain of the radar signal during the transmission and reception processes by the variable-pattern metasurface flexible passive resonant conformal antenna is exerted, enabling the induction radar to obtain stronger gain and shaping with a smaller radio frequency transmission power, realizing high-sensitivity induction control of the monitoring area, while reducing its own radiation interference and suppressing external radiation interference; the flexible conformal characteristic can facilitate the setting of the variable-pattern metasurface flexible passive resonant conformal antenna on the non-metallic material shell, and it can be attached to the non-metallic material shell, not only maintaining the beauty of the non-metallic material shell, but also directly facing the radar monitoring space, facilitating sensitive induction and identification.

[0070] The above-described embodiments only represent one implementation manner of the present invention, and its description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A radio frequency radar structure for enhancing induction sensitivity, characterized in that, Comprising: A reflective resonant cavity space formed by a non-metallic material housing and a metal base supporting a power control PCBA; An inductive radar module is disposed in the reflective resonant cavity space, and the inductive radar module at least includes: A connector with adjustable height, and a radar PCBA and the power control PCBA respectively fixed on the upper and lower surfaces of the connector; the other side of the power control PCBA is fixed on the metal base; The lower surface of the radar PCBA is adhesively fixed to the connector, and a radar antenna module is disposed on the upper surface. A variable pattern metasurface flexible passive resonant conformal antenna is disposed at a preset distance from the upper surface of the radar PCBA; The adjustable height of the connector is 1 / 4 to 1 / 2 of the radar operating wavelength, so that the distance between the radar PCBA and the variable pattern metasurface flexible passive resonant conformal antenna can be adjusted in the reflective resonant cavity space. After the power control PCBA is fixed on the metal base, the requirement of the preset distance is satisfied.

2. The radio frequency radar structure for enhancing induction sensitivity according to claim 1, wherein The variable pattern metasurface flexible passive resonant conformal antenna is disposed on the inner surface of the non-metallic material housing, or adhesively combined with the non-metallic material housing, or spaced from the non-metallic material housing by a preset distance.

3. The radio frequency radar structure for enhancing induction sensitivity according to claim 2, wherein The variable pattern metasurface flexible passive resonant conformal antenna at least includes: a transparent adhesive, a flexible substrate layer, a variable metal pattern layer, and a surface protection cover layer laminated in sequence.

4. The radio frequency radar structure for enhancing induction sensitivity according to claim 3, characterized in that The variable pattern metasurface flexible passive resonant conformal antenna further includes: microstrip patches arranged in a periodic pattern inside the variable metal pattern layer, and the microstrip patches have specific text and pattern structures; the specific text and pattern are at least any one or several of characters, rectangles, circles, and Vs.

5. The radio frequency radar structure with enhanced induction sensitivity according to claim 4, characterized in that The radar antenna module at least includes: a radar chip disposed on the radar PCBA, and Tx microstrip antennas and Rx microstrip antennas of equal size disposed on both sides of the radar chip symmetrically; the radar chip is connected to the Tx microstrip antenna and the Rx microstrip antenna respectively through a Tx port and an Rx port through coupling feed lines.

6. The radio frequency radar structure for enhancing induction sensitivity according to claim 5, wherein The long sides and short sides of the variable pattern metasurface flexible passive resonant conformal antenna respectively correspond to the long sides and short sides of the Tx microstrip antenna and the Rx microstrip antenna in a ratio of 1:1.2 to 1.8, and the variable pattern metasurface flexible passive resonant conformal antenna is at least a planar or curved surface structure.

7. The radio frequency radar structure for enhancing induction sensitivity according to claim 6, wherein, One end of the power control PCBA is connected to a load circuit, and the other end is connected to a DC power supply.

8. A radio frequency radar circuit for enhancing induction sensitivity, characterized in that, At least including: a radio frequency radar structure for enhancing induction sensitivity, and a load circuit connected in series with the radio frequency radar structure; the load circuit is at least a one-way or multi-way parallel circuit; and a DC power supply connected to the radio frequency radar structure, and the radio frequency radar structure at least includes: A connector with adjustable height, and a radar PCBA and a power control PCBA respectively fixed on the upper and lower surfaces of the connector; the other side of the power control PCBA is fixed on a metal base; The lower surface of the radar PCBA is bonded and fixed to the connector, the upper surface is provided with a radar antenna module, and a variable pattern metasurface flexible passive resonant conformal antenna is provided at a preset distance from the upper surface of the radar PCBA; The radar antenna module at least includes: a radar chip arranged on the radar PCBA, and a Tx microstrip antenna and an Rx microstrip antenna arranged on both sides of the radar chip symmetrically and of equal size; the radar chip is connected to the Tx microstrip antenna and the Rx microstrip antenna through a Tx port and an Rx port, respectively, through a coupling feeder; The adjustable height of the connector is 1 / 4 to 1 / 2 of the radar operating wavelength, so that the distance between the radar PCBA and the variable pattern metasurface flexible passive resonant conformal antenna can be adjusted in the reflective resonant cavity space. After the power control PCBA is fixed on the metal base, the preset distance requirement is met.

9. The RF radar circuit for enhancing induction sensitivity according to claim 8, wherein The variable pattern metasurface flexible passive resonant conformal antenna at least includes: a transparent backing glue, a flexible substrate layer, a variable metal pattern layer and a surface protection covering layer laminated together in sequence; the variable pattern metasurface flexible passive resonant conformal antenna also includes: microstrip patches arranged in a regular periodic pattern inside the variable metal pattern layer, and the microstrip patches have specific text and pattern structures; the specific text and pattern are at least any one or more of characters, rectangles, circles and V shapes; the long side and wide side of the variable pattern metasurface flexible passive resonant conformal antenna correspond to the long side and wide side of the Tx microstrip antenna and the Rx microstrip antenna in a ratio of 1:1.2 to 1.

8.

10. A radio frequency radar control method for enhancing induction sensitivity, characterized in that, At least: S1: Through a retractable height-adjustable connector, the distance between the variable pattern metasurface flexible passive resonant conformal antenna and the Tx microstrip antenna of the radar antenna module is adjusted to form a resonant cavity; S2: The Tx microstrip antenna of the radar antenna module transmits high-frequency electromagnetic waves at a preset frequency, which are repeatedly reflected and coupled by the variable pattern metasurface flexible passive resonant conformal antenna in the resonant cavity and then transmitted to the external sensing detection area; S3: When an active or slightly moving target appears within the sensing detection area, the variable pattern metasurface flexible passive resonant conformal antenna receives the reflected wave of the active or slightly moving target, and then transmits it to the Rx microstrip antenna of the radar antenna module through the resonant cavity; S4: The radar antenna module performs dual threshold control logic according to the reflected wave and outputs a preset control instruction.

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