CN101191837B - A signal detection device used in automatic door control system - Google Patents

Abstract

The invention relates to a signal detection device for an automatic door control system, which comprises a waveguide body, an oscillator and a frequency mixer which are positioned in the waveguide body, a coupling element and a filter element which extend into the waveguide body, an antenna connected with the waveguide body, and a short circuit board, wherein a waveguide cavity is arranged in the waveguide body, the waveguide cavity is a cube, and the oscillator and the frequency mixer are movably positioned on the right side wall and the left side wall of the waveguide cavity respectively; the front ends of the filter element and the coupling element are positioned in the waveguide cavity and are oppositely positioned on the top wall and the bottom wall of the waveguide cavity respectively. The invention adopts millimeter wave devices, and the structure of the oscillator, the frequency mixer, the coupling element and the filter element in the waveguide cavity is more compact through the structural change of the waveguide cavity, and under the condition of further reducing the volume, the depth of the oscillator and the frequency mixer in the waveguide cavity is adjusted through the pipe seat in threaded connection, the frequency and the power of the oscillator are adjusted, and the efficiency and the receiving sensitivity of the frequency mixer are improved.

Description

A signal detection device used in automatic door control system

technical field

The invention relates to a signal detection device used in an automatic door control system.

Background technique

At present, most of the signal detection devices used in the automatic door control system adopt the following two technical solutions: the first one is an infrared detector, which uses infrared radiation characteristics to obtain target information. Regardless of whether the person moves or not, as long as it is within the scanning range of the infrared detector, it will sense the target (human body) information, thereby generating a trigger signal to open the automatic door. The disadvantage of this technical solution is that the response speed of infrared detection is relatively slow, and it is suitable for places where people with slow movements come in and out, and this kind of infrared detection is greatly affected by the environment, such as temperature, humidity, smoke, dust, etc., long-term use will cause Misoperation or inaction. In addition, if the automatic door receives the trigger signal for too long, the controller will think that there is an obstacle in the signal input system, and if the automatic door is kept open for too long, it will also cause damage to the electrical components. Due to the above-mentioned shortcomings, it is rarely used in the automatic door control system in the world at present.

The other is a microwave detector, which uses the microwave reflection characteristics to obtain target information, and at the same time uses the Doppler principle to obtain target motion information, that is, it is generated by mixing the transmitted microwave radio frequency signal with the received echo signal of the moving target. The difference frequency signal obtains the motion information of the target (human body). The technical solution has a fast response speed and is suitable for places where people with normal walking speed pass. The feature is that the work of the detector is hardly affected by the surrounding environment such as temperature, air flow, dust, humidity, smoke and noise. The microwave detector has strong anti-radio frequency interference ability, low output power, and no harm to the human body. And once the people near the door do not want to go out and stay still, the detector will no longer respond, and the automatic door will be closed, which has a certain protective effect on the door operator. Because this solution has the above-mentioned advantages, and compared with the infrared detector, it is smaller in size, lower in cost and more sensitive in response, so it has been widely used in the existing automatic door control system.

In the existing microwave detectors, since the oscillator and mixer are placed in the waveguide cavity, the microwave detector with the same cavity frequency is beneficial to reduce the volume, but the corresponding problem is that the frequency adjustment is inconvenient. The structure is complex and cannot meet the requirements of high overload. For example, the patent No. 86100585 published by the Chinese Patent Office on the date of the year, the patent name is: "Doppler radar microwave component" in the invention patent, which discloses a multi-frequency mixing tube and an oscillating tube located in the same waveguide cavity. Puller radar microwave components. The component adopts an adjustable probe mixer, and the depth inserted into the waveguide can be adjusted, so that the mixing efficiency can be changed. The disadvantage of this component is that the waveguide between the mixing tube and the oscillator in the component needs a certain length to meet the condition of no direct coupling, and the volume cannot be reduced; the oscillator is fixedly connected across the waveguide cavity, and its frequency needs another Adjustable screw tuning has a complex structure and is inconvenient to debug; and due to the complex structure and too many adjustable parts, it is difficult to meet the requirements of higher frequency bands; the working frequency bands of existing detectors using microwaves are 9.3GHz and 24.125GHz. If the band is further increased, the sensitivity and response speed can be improved.

Contents of the invention

In order to solve the above-mentioned problems and deficiencies in the prior art, the present invention provides a signal transceiving device used in an automatic door control system.

The main technical solution adopted in the present invention is: a signal detection device used in an automatic door control system, including a waveguide body, an oscillator and a mixer located in the waveguide body, and a Coupling element, filter element, antenna connected to the waveguide body, short circuit board, the waveguide body has a waveguide cavity inside, the waveguide cavity is a cube, and the oscillator and mixer are movable They are respectively located on the right side wall and the left side wall of the waveguide cavity; the front ends of the filter element and the coupling element are located in the waveguide cavity, and are oppositely located on the top wall and the bottom wall of the waveguide cavity .

The present invention also adopts the following subsidiary technical solution: the oscillator and the mixer located on the left side wall and the right side wall of the waveguide cavity are located in the same axial direction.

The waveguide body is provided with a first threaded hole and a second threaded hole connected to the position of the symmetry axis of the right side wall and the left side wall of the waveguide cavity, and the first threaded hole and the second threaded hole are respectively It is threadedly connected with the first tube base and the second tube base, the mixer is fixed at the front end of the first tube base, and the oscillator is fixed at the front end of the second tube base.

Both the coupling element and the filter element are standard feedthrough capacitors, and the waveguide body is provided with a first through hole and a second through hole connected to the top wall and the bottom wall of the waveguide chamber, so The coupling element is placed in the first through hole, and its front end extends into the waveguide cavity; the filter element is placed in the second through hole, and its front end extends into the waveguide cavity.

The waveguide body is a cube, the short circuit board is connected to the front end of the waveguide body, and the signal transmitting/receiving antenna is connected to the opposite rear end.

The waveguide cavity is filled with shock-absorbing materials with a dielectric constant _a1 between 1.0 and 1.2.

The shock-absorbing material is a granular elastic plastic foam.

The dimensions of the left side wall, the right side wall, the top wall and the bottom wall of the waveguide cavity are not larger than: 8.00mm×4.00mm.

The dimensions of the left side wall, the right side wall, the top wall and the bottom wall of the waveguide cavity are: 7.10mm×3.55mm.

The coupling element and filter element located on the top wall and the bottom wall of the waveguide cavity are located in the same radial direction.

The beneficial effects brought by the adoption of the present invention: (1) The present invention sets the waveguide cavity in the waveguide as a cube, and the oscillator and the mixer are respectively arranged on the left and right side walls of the waveguide cavity, and are in the In the same axial direction, the coupling element and the filter element are respectively arranged on the top wall and the bottom wall of the waveguide cavity, the internal structure is simplified and more compact, the volume is reduced, the weight is reduced, and it is easy to mass produce. (2) Through the threaded socket, the depth of the oscillator and mixer into the waveguide cavity can be adjusted, which is convenient for debugging. Not only can the frequency and power of the oscillator be changed, but also the offset and receiving sensitivity of the mixer can be changed. , in the case of reduced volume, convenient debugging, improved efficiency, and reduced power consumption. (3) The waveguide cavity is filled with special shock-absorbing material, which does not affect the electrical performance and can withstand the impact acceleration of more than 25000g. (4) The present invention adopts the millimeter wave band signal, the beam is narrower than the microwave, has a wider bandwidth, the frequency range can reach 30-300 GHz, the sensitivity is higher, the response speed is faster, and it has all-weather characteristics.

Instructions attached

Fig. 1 is a schematic diagram of the front structure of the waveguide in the signal detection device of the present invention;

Fig. 2 is the A-A direction sectional view of Fig. 1;

Fig. 3 is the B-B direction sectional view of Fig. 1;

Fig. 4 is the front sectional view of the signal detection device of the present invention;

5 is a schematic side view of the signal detection device of the present invention;

Fig. 6 schematic diagram of the equivalent circuit of the millimeter-wave fuze tuner of the present invention;

Detailed ways

Below in conjunction with accompanying drawing, the present invention is described in further detail:

As shown in Figures 1 to 5, a signal detection device used in an automatic door control system includes a waveguide body 1, an oscillator 12 located in the waveguide body, a mixer 13, and a coupling element extending into the waveguide body 14. The filter element 15, the antenna 2 connected to the waveguide body, the short circuit board 3, the waveguide body 1 has a waveguide cavity 11 inside, the waveguide cavity 11 is a cube, and the oscillator 12 and the mixer 13 are movable respectively. Located on the right side wall and left side wall of the waveguide cavity 11; the front ends of the filter element 15 and the coupling element 14 are located in the waveguide cavity 11, and oppositely located on the top wall and the bottom wall of the waveguide cavity 11 respectively.

The dimensions of the left side wall, the right side wall, the top wall and the bottom wall of the waveguide cavity 11 are not larger than: 8.00mm×4.00mm. In this embodiment, the dimensions of the left side wall, right side wall, top wall, and bottom wall of the waveguide cavity 11 are: 7.10mm×3.55mm. As shown in Fig. 2, Fig. 3 and Fig. 4, the waveguide body 1 is provided with a first threaded hole 16 and a second threaded hole 16' which communicate with the position of the symmetry axis of the right side wall and the left side wall of the waveguide cavity 11. , the first threaded hole 16 and the second threaded hole 16' are threadedly connected with the first tube base 17 and the second tube base 18 respectively, the mixer 13 is fixed on the front end of the first tube base 17, and the oscillator 12 is fixed on the first tube base 17 The front end of the second pipe seat 18. In this way, the oscillator 12 and the mixer 13 located on the left side wall and the right side wall of the waveguide cavity 11 are located in the same axial direction, and the oscillator 12 and the frequency mixer can be adjusted by rotating the tube base during use. The depth of the device 13 protruding into the waveguide cavity realizes the adjustable frequency and power. Both the coupling element 14 and the filter element 15 adopt standard through-hole capacitors in this embodiment, and the first through hole 19 and the second through hole connected to the top wall and bottom wall of the waveguide chamber 11 are opened on the waveguide body 1. 19 ′, the coupling element 14 is placed in the first through hole 19 , and its front end extends into the waveguide cavity 11 , the filter element 15 is placed in the second through hole 19 ′, and its front end extends into the waveguide cavity 11 . In order to realize this technical solution, it is required that the front ends of the coupling element 14 and the filter element 15 extend into the waveguide cavity. As for the other parts of the coupling element 14 and the filter element 15, there are no strict requirements, they can be completely inserted into the waveguide body 1 as a whole, or there are A part is exposed outside the waveguide body 1 . In this embodiment, the front ends of the coupling element 14 and the filter element 15 protrude into the waveguide cavity 11 , and the other ends are exposed outside the waveguide body 1 .

As shown in Fig. 4 and Fig. 5, in this embodiment, the shape of the waveguide cavity 11 is a cube, and there is no special requirement for the shape of the waveguide body 1. For the convenience of processing and manufacturing, the shape of the waveguide body 1 of this embodiment is Cubes are also used. A short circuit board 3 is connected to the front end of the waveguide body 1 , and an antenna 2 is connected to the opposite rear end.

As shown in Figure 6, the oscillating tube 12 and the mixing tube 13 are located on the right side wall and the left side wall of the waveguide cavity 11, and are in the same axial direction, with a longitudinal distance of about λ/2 (λ is the working wavelength). 14 is welded to the mixer 13, the filter element 15 is welded to the oscillator 12, one end of the waveguide body 1 is short-circuited, the other end is the power output, the feed of the oscillation tube 12 and the Doppler on the mixer 13 Signal extraction is performed through the filter element 15 and the coupling element 14 located on the waveguide cavity 11 respectively. In Fig. 6, the equivalent circuit of the body effect tube is connected to the AB end, and the equivalent circuit of the mixer tube 13 is connected to the two ends of CD. The oscillating tube 12, the waveguide cavity 11, and the short-circuit surface constitute a resonant circuit. When the starting conditions are met, oscillation is generated, and the power generated by the oscillation is radiated outward, and a small part of it is added to the mixing tube 13 at the CD end, which is equivalent to providing A local oscillator voltage for the mixer tube 13. The invention adopts the millimeter wave band signal, the beam is narrower than the microwave, has a wider bandwidth, the frequency range can reach 30-300GHz, the sensitivity is greatly improved, the response speed is accelerated, and it has all-weather characteristics. In this embodiment, the working frequency is between 32 GHz and 39 GHz. The echo signal generated when the transmitted signal encounters the target is added to the mixer tube 13, and the two are mixed to generate a Doppler signal. Since the oscillating tube 12 and the mixing tube 13 exist in the waveguide cavity 11, the oscillating frequency, oscillating power and mixing sensitivity all affect each other. In the debugging process of this embodiment, adjust the oscillating tube 12 and the mixing tube 13 The protruding position in the waveguide cavity 11 enables its transmission power and frequency mixing sensitivity to reach the best state. In order to enhance the anti-seismic performance, in this embodiment, the waveguide cavity 11 is filled with a shock-absorbing material 111 with a dielectric constant _a1 between 1.0-1.2, and the shock-absorbing material 111 is a granular elastic plastic foam.

Claims (10)

1. A signal detection device used in an automatic door control system, comprising a waveguide body (1), an oscillator (12) and a mixer (13) positioned in the waveguide body, extending into the waveguide body A coupling element (14), a filter element (15), and an antenna (2) connected to the waveguide body, a short circuit board (3), the waveguide body (1) has a waveguide cavity (11) inside, It is characterized in that: the waveguide cavity (11) is a cube, and the oscillator (12) and the mixer (13) are respectively movable on the right side wall and the left side wall of the waveguide cavity (11) Above; the front ends of the filter element (15) and the coupling element (14) are located in the waveguide cavity (11), and oppositely located on the top wall and the bottom wall of the waveguide cavity (11). 2. The signal detection device according to claim 1, characterized in that: the oscillator (12) and the mixer (13) located on the left side wall and the right side wall of the waveguide cavity (11), in the same axial direction. 3. The signal detection device according to claim 1 or 2, characterized in that: the waveguide body (1) is provided with the position of the axis of symmetry with the right side wall and the left side wall of the waveguide cavity (11). The first threaded hole (16) and the second threaded hole (16') connected through each other, the first threaded hole (16), the second threaded hole (16') are respectively connected with the first socket (17) and the second The tube base (18) is threadedly connected, the mixer (13) is fixed on the front end of the first tube base (17), and the oscillator (12) is fixed on the front end of the second tube base (18). front end. 4. The signal detection device according to claim 3, characterized in that: the coupling element (14) and the filter element (15) are both standard feedthrough capacitors, and there are holes on the waveguide body (1) A first through hole (19) and a second through hole (19') connected with the top wall and bottom wall of the waveguide chamber (11), the coupling element (14) is placed in the first through hole (19), the front end of which extends into the waveguide cavity (11), the filter element (15) is placed in the second through hole (19'), and its front end extends into the waveguide cavity (11) Inside. 5. The signal detection device according to claim 3, characterized in that: the waveguide body (1) is a cube, the short circuit board (3) is connected to the front end face of the waveguide body (1), and the opposite The signal transmitting/receiving antenna (2) is connected on the rear end face. 6. The signal detection device according to claim 3, characterized in that: the waveguide cavity (11) is filled with a shock-absorbing material (111) with a dielectric constant _a1 between 1.0-1.2. 7. The signal detection device according to claim 6, characterized in that the shock absorbing material (111) is a granular elastic plastic foam. 8. The signal detection device according to claim 3, characterized in that: the size of the left side wall, right side wall, top wall and bottom wall of the waveguide cavity (11) is not greater than: 8.00mm×4.00mm. 9. The signal detection device according to claim 9, characterized in that the size of the left side wall, right side wall, top wall and bottom wall of the waveguide cavity (11) is: 7.10mm×3.55mm. 10. The signal detection device according to claim 3, characterized in that: the coupling element (14) and filter element (15) located on the top wall and bottom wall of the waveguide cavity (11) are located on the same path up direction.

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