Multi-specification onboard antenna mainboard easy to replace and wireless smoke sensing transceiving device

Abstract

The utility model discloses a multi-specification onboard antenna mainboard easy to replace and a wireless smoke sensing transceiver, and relates to the technical field of wireless communication equipment and independent smoke sensing detection alarms. According to the multi-specification onboard antenna mainboard easy to replace and the wireless smoke sensing transceiving device, a radio frequency module and an onboard antenna are integrated on the PCB mainboard, the onboard antenna is directly etched on the PCB mainboard, a function module is further integrated on the PCB mainboard, and the radio frequency module and the onboard antenna are integrated on the PCB mainboard. The function module is composed of a control module, a smoke sensing module, a buzzer module, a wireless communication module, a battery power supply module and a battery switch module, the antenna platform of various mainstream systems is designed in an integrated mode, different board cards can be selected for different markets, an antenna and a PCB are integrated together, the integration level and consistency are improved, and the cost is reduced. The complexity and the cost of equipment deployment are reduced; the antenna is directly integrated on the circuit board of the detector to form an integrated structure, additional wiring or external antenna installation is not needed, and the installation process is simplified.

Description

Technical Field

[0001] The utility model relates to the technical field of wireless communication equipment and independent smoke detection alarms, in particular to an easily replaceable multi-specification onboard antenna mainboard and a wireless smoke sensor transceiver. Background Art

[0002] In the current field of wireless communication and Internet of Things technology, onboard antenna platforms and wireless smoke transceivers are key components and are widely used in smart homes, fire warnings, environmental monitoring and other scenarios. There are currently a variety of antenna platforms on the market, such as the SUB 1G private network band. There are three main frequency bands in the world, domestic, 862-870Mhz band, and 902-928Mhz band. Each standard often corresponds to specific application scenarios and frequency band requirements. However, most of these traditional designs have great differences in structure, devices, and antennas in the same series of product designs, which brings many difficulties to material management, production cost control, component matching reuse rate, assembly, and factory maintenance and restocking. Utility Model Content

[0003] In view of the deficiencies of the prior art, the utility model provides an easily replaceable multi-specification onboard antenna mainboard and a wireless smoke sensor transceiver, which solves the problems of the prior art.

[0004] To achieve the above purpose, the utility model is implemented through the following technical solutions: a wireless smoke sensing transceiver, including a structural upper shell, a structural middle shell and a structural bottom shell, and the structural upper shell and the structural bottom shell are respectively installed on the upper and lower surfaces of the structural middle shell by bolts, a structural middle shell bracket is provided on the top of the structural middle shell, and a PCB mainboard is installed on the structural middle shell bracket through a groove, a radio frequency module and an onboard antenna are integrated on the PCB mainboard, and the onboard antenna is directly etched on the PCB mainboard, and a functional module is also integrated on the PCB mainboard, and the functional module consists of a control module, a smoke sensing module, a buzzer module, a wireless communication module, a battery power supply module, and a battery switch module, and an indicator light and a button are provided on the structural upper shell.

[0005] The utility model also discloses an easily replaceable multi-specification on-board antenna mainboard, comprising a PCB mainboard, a radio frequency module and an on-board antenna, wherein the PCB mainboard comprises three types: low frequency band, medium frequency band and high frequency band.

[0006] Preferably, the onboard antenna on the low-frequency band PCB mainboard is a 470Mhz onboard antenna, and a first π-type antenna matching circuit is also integrated on the low-frequency band PCB mainboard.

[0007] Preferably, the 470Mhz on-board antenna includes a 470Mhz antenna body. The two ends of the 470Mhz antenna body are respectively connected to a first antenna end and a shorting stub. An extension stub is connected to the side between the 470Mhz antenna body and the first antenna end. An antenna width is connected to the side between the 470Mhz antenna body and the shorting stub. One end of the antenna width is connected to a first feed stub. The first π-type antenna matching circuit is connected to the first feed stub, and the first π-type antenna matching circuit includes a first parallel matching position a, a first series matching position, and a first parallel matching position b.

[0008] Preferably, the on-board antenna on the PCB main board in the middle frequency band is an 868Mhz on-board antenna. The 868Mhz on-board antenna includes a 470Mhz antenna body. The two ends of the 470Mhz antenna body are respectively connected to a second antenna end and a second feed stub.

[0009] Preferably, the on-board antenna on the PCB main board in the high frequency band is a 915Mhz on-board antenna, and a second π-type antenna matching circuit is also integrated on the PCB main board in the high frequency band.

[0010] Preferably, the 915Mhz on-board antenna includes a 915Mhz antenna body. The two ends of the 915Mhz antenna body are respectively connected to a third antenna end and a third feed stub. The second π-type antenna matching circuit is connected to the third feed stub, and the second π-type antenna matching circuit includes a second parallel matching position a, a second series matching position, and a second parallel matching position b.

[0011] Preferably, the battery switch module is divided into a disconnection fault detection switch and a power supply switch. It is used as a disconnection detection switch when applied in the low frequency band, and as a power supply switch when applied in the middle frequency band and the high frequency band.

[0012] The utility model provides an easily replaceable multi-specification on-board antenna main board and a wireless smoke detector transceiver device. Compared with the prior art, it has the following beneficial effects:

[0013] Highly integrated, antenna platformization for different modes: The integrated design of antenna platforms of multiple mainstream systems. For different markets, different boards can be selected. The antenna is integrated with the PCB, improving the integration and consistency, and reducing the complexity and cost of equipment deployment.

[0014] Integrated on-board antenna design: The antenna is directly integrated on the detector's circuit board to form an integrated structure, eliminating the need for additional wiring or installation of external antennas, simplifying the installation process, and improving the overall aesthetics of the device. This design also optimizes the antenna layout to ensure the stability and efficiency of signal transmission.

[0015] Small space occupancy and easy installation: The compact on-board design significantly reduces the device volume, facilitating installation and deployment in narrow spaces, meeting the development trend of miniaturization and integration of Internet of Things devices.

[0016] Convenient maintenance and low cost: Fewer components reduce the complexity and cost of maintenance. For engineering, simply replacing the entire main board can adjust the communication mode, reducing the later factory maintenance cost. More standardized components reduce the complexity of the maintenance BOM for the entire series. Description of the Drawings

[0017] Figure 1 It is the assembly drawing of the wireless smoke sensor transceiver device of the present utility model;

[0018] Figure 2 It is the exploded view of the wireless smoke sensor transceiver device of the present utility model;

[0019] Figure 3 It is the schematic diagram of the circuit module principle of the wireless smoke sensor transceiver device of the present utility model;

[0020] Figure 4 It is the schematic diagram of the first embodiment of the on-board antenna platform of the present utility model;

[0021] Figure 5 For the present utility model Figure 4 The schematic diagram of the on-board antenna therein;

[0022] Figure 6 It is the schematic diagram of the second embodiment of the on-board antenna platform of the present utility model;

[0023] Figure 7 For the present utility model Figure 6 The schematic diagram of the on-board antenna therein;

[0024] Figure 8 It is the schematic diagram of the third embodiment of the on-board antenna platform of the present utility model;

[0025] Figure 9 For the present utility model Figure 8 The schematic diagram of the on-board antenna therein.

[0026] In the figure: 1 - structural upper shell, 2 - structural middle shell, 3 - structural bottom shell, 4 - structural middle shell bracket, 5 - PCB main board, 6 - radio frequency module, 7 - function module, 8 - three-color indicator light, 9 - button;

[0027] 11 - 470Mhz On - board Antenna, 111 - 470Mhz Antenna Body, 112 - First Antenna End, 113 - Short - circuit Stub, 114 - Extension Stub, 115 - Antenna Width, 116 - First Feed Line Stub, 117 - First Parallel Matching Bit a, 118 - First Series Matching Bit, 119 - First Parallel Matching Bit b, 12 - First Pi - type Antenna Matching Circuit;

[0028] 21 - 868Mhz On - board Antenna, 211 - 470Mhz Antenna Body, 212 - Second Antenna End, 213 - Second Feed Line Stub;

[0029] 31 - 915Mhz On - board Antenna, 311 - 915Mhz Antenna Body, 312 - Third Antenna End, 313 - Third Feed Line Stub, 314 - Second Parallel Matching Bit a, 315 - Second Series Matching Bit, 316 - Second Parallel Matching Bit b, 32 - Second Pi - type Antenna Matching Circuit. Detailed Implementation Manner

[0030] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present utility model.

[0031] Refer to Figures 1-3 , the present utility model discloses a wireless smoke detector transceiver device, including a structural upper shell 1, a structural middle shell 2, and a structural bottom shell 3. The structural upper shell 1 and the structural bottom shell 3 are respectively installed on the upper and lower surfaces of the structural middle shell 2 through bolts. A structural middle shell bracket 4 is provided at the top of the structural middle shell 2, and a PCB main board 5 is installed on the structural middle shell bracket 4 through a groove. A radio frequency module 6 and an on - board antenna are integrated on the PCB main board 5, and the on - board antenna is directly etched on the PCB main board 5. A function module 7 is also integrated on the PCB main board 5. The function module 7 is composed of a control module, a smoke sensing module, a buzzer module, a wireless communication module, a battery power supply module, and a battery switch module. An indicator light 8 and a button 9 are provided on the structural upper shell 1. The basic color of the indicator light 8 is single red light, and three - color lights of red, green, and yellow can be selected in the low - frequency band to enhance the prompting effect of the indicator light.

[0032] The system architecture of the wireless smoke detector transceiver device includes:

[0033] The battery-powered module supplies power to the following four parts, namely the control module, the buzzer module, the wireless communication module, and the information storage module, through a specially designed battery switch module that meets national standards; the battery switch module is divided into a disconnection fault detection switch and a power supply switch, which acts as a disconnection detection switch when applied in the low frequency band and as a power supply switch when applied in the medium and high frequency bands.

[0034] The information processing unit, as the logical master control and information processing unit of the entire product, is responsible for processing the following three basic functions and other control logics:

[0035] Collect sensor data, collect data from the smoke detection module, and process and analyze the signals received by the photodiodes to determine whether there is smoke present;

[0036] Execute control logic, execute the control logic of the detector, including functions such as starting an alarm and resetting. It can judge whether to trigger an alarm according to the preset threshold;

[0037] Data communication, responsible for communicating with the wireless communication module, transmitting the status information and alarm signals of the detector. The MCU can also manage the power supply of the detector to ensure the normal operation of the device in the low power consumption mode;

[0038] Smoke detection module: The control module controls the lighting and extinguishing of the red and blue double-light emitting tubes in the maze of the smoke detection module through 2 red and blue light control lines, generating detection lights of different wavelengths (the red light has a longer wavelength and the blue light has a shorter wavelength) to sense smokes of different particle sizes (black smoke is not completely burned and has large particles; white smoke is mainly composed of water vapor and smaller particles; the long-wavelength red light detects black smoke, and the short-wavelength blue light detects white smoke), and detects the smoke concentration in the maze in a complementary manner. The photoelectric receiving tubes in the maze will sense the corresponding light signals at different smoke concentrations, and then generate corresponding currents. After the control module amplifies this current through the IV conversion circuit and processes it through an algorithm, the detector can sense the smoke concentration in the surrounding environment and then trigger a fire alarm;

[0039] Wireless communication module: The control module is connected to the wireless communication module through a data line for data interaction. Through the wireless communication module, a wireless local area network can be formed with other Qingniao products. After a single detector senses a fire, it can send a fire alarm signal to the entire building through the wireless local area network to trigger a fire alarm linkage;

[0040] Information storage module: The control module is connected to the information storage module through the internal data bus and can store information such as daily operation logs and alarms;

[0041] Clock module: The clock module is connected to the information processing unit through a clock line to synchronize the clock information and ensure the system clock synchronization;

[0042] Encryption module: The information processing unit is connected to the encryption module through the internal data bus to verify the product information in an encrypted form to prevent the product from being illegally disassembled and user information from being leaked;

[0043] Buzzer module: The boost drive unit in the buzzer module draws power from the battery power supply module through the battery switch module. The information processing unit regulates the boost drive unit through the control line and obtains its actual voltage value through the feedback line, thus playing the role of a boost regulation closed loop. The buzzer drive module and buzzer draw power from the boost module. When the detector identifies surrounding fire information or executes self-test logic, the information processing unit first regulates the boost module to output a suitable voltage, and then controls the buzzer to sound through the buzzer control line to achieve a sound intensity that meets relevant standards.

[0044] Working principle of smoke circuit: The red and blue dual-light photoelectric smoke detector mainly realizes smoke detection and LAN alarm through the following functions:

[0045] Signal control and acquisition logic of the smoke sensing module: The information processing unit controls the red and blue dual light emitting tubes in the smoke sensing module to emit long and short wavelength light respectively to detect large-particle black smoke and small-particle white smoke; the photodiode receives the light reflected / refracted by the smoke (under normal conditions, there is no smoke in the maze, so it is almost impossible to receive it). When smoke enters the maze of the smoke sensing module, the light intensity received by the photodiode changes (the thicker the smoke, the higher the light intensity received), thereby generating current signals of different sizes. After this current signal is amplified by the IV conversion circuit and processed by the algorithm in the information processing unit, the detector identifies whether a fire has occurred in the surrounding area. It then decides whether to trigger the alarm action;

[0046] Alarm system: When the information processing unit detects smoke exceeding the threshold concentration, it activates the alarm system and sends out an audible alarm signal through the buzzer drive circuit to alert the user. It also sends an alarm signal to the wireless LAN through the wireless communication module, thereby triggering the fire alarm in the area, prompting personnel to evacuate and escape, and extinguishing the fire.

[0047] Power management: The circuit design includes power supply and power switch control related modules to ensure that the product is used in accordance with the standards;

[0048] Information encryption and information storage: The circuit design includes an information encryption module, which is used to encrypt user information and prevent illegal cracking of products. In addition, the information storage module is used to store important information such as product operation logs and fire alarms.

[0049] Use wireless dual-light photoelectric smoke detectors, which use red light and blue light frequency bands to detect aerosol particles, to improve the problem that single red light is not good for scenes such as water vapor.

[0050] Intelligent smoke detection algorithm: Built-in high-performance microprocessor, running optimized smoke detection algorithm, can accurately identify and quickly respond to fire smoke, reducing the occurrence of false alarms and missed alarms.

[0051] Low power consumption design: The use of low power consumption components and intelligent power management technology ensures that the device can maintain high performance even in long standby mode, thus extending the battery life.

[0052] Integrated shell design: The integrated shell design not only protects the internal circuit and antenna, but also greatly improves the aesthetics of the product. It is suitable for various installation environments and reduces the complexity of assembly.

[0053] Intelligent self-check and calibration: Integrated intelligent self-check and calibration functions can automatically detect the performance consistency of the antenna at the factory stage and make necessary calibration to ensure long-term stable communication performance.

[0054] See also Figures 4-9 The utility model also discloses an easily replaceable multi-specification onboard antenna mainboard, and provides the following three technical solutions:

[0055] Embodiment 1: comprising a 470Mhz frequency band PCB mainboard 5, a radio frequency module 6 and an onboard antenna;

[0056] The onboard antenna on the low-frequency band PCB mainboard 5 is a 470Mhz onboard antenna 11 , and a first π-type antenna matching circuit 12 is also integrated on the low-frequency band PCB mainboard 5 .

[0057] The 470Mhz onboard antenna 11 includes a 470Mhz antenna body 111, the two ends of the 470Mhz antenna body 111 are respectively connected to the first antenna end 112 and the short-circuit branch 113, the side between the 470Mhz antenna body 111 and the first antenna end 112 is connected to the extension branch 114, the side between the 470Mhz antenna body 111 and the short-circuit branch 113 is connected to the antenna width 115, and one end of the antenna width 115 is connected to the first feed branch 116, and the first π-type antenna matching circuit 12 is connected to the first feed branch 116.

[0058] The RF module 6 of this embodiment includes a RF transceiver circuit, including a transmitting module and a receiving module, which are connected to a 470Mhz onboard antenna 11 to realize wireless communication function. The first π-type antenna matching circuit 12 is an impedance matching circuit reserved for the antenna in the hardware layout, which is a part of the onboard antenna. The antenna is debugged by serial and parallel inductors and capacitors to obtain better impedance matching and wider working bandwidth.

[0059] Clearance processing is performed around the first antenna end 112, the short-circuit branch 113, the extended branch 114, the antenna width 115 and the first feed branch 116 to ensure the radiation efficiency of the antenna.

[0060] The first π-type antenna matching circuit 12 includes a first parallel matching bit a117, a first series matching bit 118, and a first parallel matching bit b119. It adjusts the antenna through series and parallel inductors and capacitors, and is used to assist in optimizing the antenna performance on the basis of the on-board antenna trace debugging to obtain better impedance matching and a wider operating bandwidth. Among them, the first parallel matching bit a117 is the matching bit closest to the antenna end and takes effect first. In the embodiment of the present invention, the operating frequency band of the antenna is 470Mhz. This matching bit can shunt an inductor according to the position on the SMITH chart to make the required frequency point rotate counterclockwise around the constant conductance circle. Adjust the size of the inductor so that it intersects the r = 1 circle in the first quadrant, and then series a capacitor with the first series matching bit 118 to make the required frequency point move counterclockwise along the r = 1 circle. Adjust the size of the capacitor until it reaches the 50-ohm optimal matching position at the center of the chart. For the single-frequency operating frequency band of this embodiment, the matching scheme used is not unique, and the optimal matching circuit can be selected according to actual debugging. In this example, the required operating frequency band is relatively low, and the area required for a quarter wavelength of the main board trace is relatively large. To save area, expand the antenna trace, increase the clearance, and keep away from metals, matching bits need to be reserved and optimized.

[0061] The line length of the first feed line stub 116 is 14.66mm, and the line width is 2.52mm. It is led out from the RF module 6, passes through the first π-type antenna matching circuit 12, and routes to the clearance area at the edge of the board. At the beginning of the design of this structure, the hardware layout is made as compact as possible, which can save the PCB area to save costs, and can also squeeze out a larger clearance area for the on-board antenna. The first feed line stub 116 routes to the edge of the PCB main board 5, with a length of 14.66mm, which determines the overall antenna layout and the overall trace shape. It can be adjusted according to the actual size of the PCB main board 5 and the environmental clearance. In the embodiment of the present invention, it routes in the opposite direction to the reference ground and reaches the edge of the board structure to obtain a larger clearance and better antenna radiation directivity. The feed line outlet position leaves a position and area for the subsequent short-circuit stub 113, introduces an IFA antenna, adjusts the impedance, and optimizes the resonance and bandwidth. The line width of the first feed line stub 116 is 2.52mm. This width enables the entire antenna layout to strive for a larger overall clearance in terms of structure, and adjusts the width to adjust the impedance and bandwidth to obtain better return loss.

[0062] The line width of the antenna short-circuit stub 113 is 2.52mm, and the line length is about 24.72mm. It is led out from the reference ground at the edge of the PCB main board 5 and intersects with the end of the first feed line stub 116 of the antenna at the edge of the PCB main board 5 structure to form an IFA antenna, which plays a role equivalent to a shunt inductor to adjust the antenna inductive reactance. The intersection position and the position led out from the reference ground can be adjusted according to parameters such as the size and shape of the PCB, the SMITH chart, and S11 to optimize the antenna performance. This section of the trace routes with the largest possible area to expand the radiation area, which can improve the radiation efficiency and optimize the radiation directivity.

[0063] The wire length of the 470Mhz antenna main body 111 is about 38.49mm, and the wire width is 2.52mm. This section of the trace is led out by the first feeder stub 116, and runs parallel to the reference ground along the 5 sides of the PCB main board 5 at the maximum distance. Clearance is made around it. This section of the trace enlarges the overall area and size of the antenna to obtain better radiation performance and better radiation directivity. The shape and length of the 470Mhz antenna main body 111 determine the layout and shape of the subsequent antenna structure. Keeping this width under the condition of the limited area of the PCB main board 5 can obtain a wider bandwidth, and at the same time leave enough area to ensure that the length of the subsequent trace of the antenna is sufficient to be tuned to the required operating frequency band; the relative distance between this trace and the reference ground is adjustable, which is used to optimize the antenna return loss, radiation efficiency, radiation direction, etc.

[0064] The extended stub 114, one section of which is 14.99mm long and 2.52mm wide, is led out from the 470Mhz antenna main body 111 and continues to run along the edge of the PCB main board 5 with the maximum clearance; the other section is a U-shaped trace, which is also led out from the 470Mhz antenna main body 111 and closes at the end of the first section, with the same width of 2.52mm. The turning lengths of the three sections of the U-shape are shown in the figure as: 27.23mm, 12.88mm, and 20.48mm respectively. This section of the trace mainly serves to lengthen the antenna to tune to the required operating frequency band. Since the required frequency band in this example is relatively low, this section of the trace is used to lengthen it, and at the same time increase the radiation area and improve the radiation performance. Clearance is also made at the 'U-shaped' direction, the PCB is not ordinary, the reference ground is hollowed out, and other metals are also avoided to improve the antenna performance.

[0065] The first antenna end 112 is the last section of the trace structure of this antenna, with a length of about 22.57mm and a width of 2.52mm. This section of the trace is led out from the extended stub 114 and runs along the edge of the board. The length of this trace and the extended stub 114 together determine the final required operating frequency point. When designing the hardware layout, the antenna environment is considered, and the layout is designed to be more compact. On the one hand, it can save costs, and on the other hand, it can obtain a larger clearance for the antenna. No devices or copper plating are arranged in the direction of the first antenna end 112, so that the antenna can obtain better radiation performance.

[0066] Embodiment 2: It includes a medium-frequency PCB main board 5, a radio frequency module 6, and an on-board antenna;

[0067] The on-board antenna on the medium-frequency PCB main board 5 is the 868Mhz on-board antenna 21. The 868Mhz on-board antenna 21 includes a 470Mhz antenna main body 211, and the two ends of the 470Mhz antenna main body 211 are respectively connected to a second antenna end 212 and a second feeder stub 213.

[0068] The RF module 6 of the PCB main board 5 includes an RF transceiver circuit, which consists of a transmitting module and a receiving module, and is connected to the 868Mhz on-board antenna 21 to achieve wireless communication functions.

[0069] Clearance processing is performed around the 470Mhz antenna body 211, the second antenna end 212, and the second feed line stub 213 to ensure the radiation efficiency of the antenna.

[0070] The length of the second feed line stub 213 is 7.8mm and the width is 0.76mm. It is led out from the RF module 6 and runs parallel to the reference ground direction. At the beginning of the design of this structure, the hardware layout is made as compact as possible, which can save the PCB area to reduce costs and can also create a larger clearance area for the on-board antenna. This section of the structure runs a distance of 7.8mm away from the reference ground where the RF module 6 is mounted, and clearance processing is performed at the bottom and around it to layout for the subsequent 470Mhz antenna body 211 to be perpendicular to the reference ground by 90 degrees to increase the radiation area, which determines the overall antenna layout and the overall wiring shape. It can be adjusted according to the actual size of the PCB board and the environmental clearance. In the embodiment of the present invention, the second feed line stub 213 runs parallel to the reference ground at a certain distance to obtain a larger clearance and better antenna radiation directivity. The end position of the feed line outlet leaves a position and area for the subsequent 470Mhz antenna body 211 stub. The width of the second feed line stub 213 is 0.76mm, and this width structurally enables the entire antenna layout to strive for a larger overall clearance, and the impedance and bandwidth are adjusted by adjusting the width to obtain better return loss.

[0071] The length of the 470Mhz antenna body 211 is 17.67mm and the width is 2.65mm. This part of the antenna runs perpendicular to the second feed line stub 213 to take the antenna body away from the reference ground to obtain a better clearance. The width of this part of the antenna is 1.89mm wider than the 0.76mm width of the second feed line stub 213 for adjusting the bandwidth and impedance of the antenna and optimizing the smith chart. At the same time, this part of the antenna structure goes straight to the board edge and is perpendicular to the relative reference ground direction to obtain the maximum clearance, which can optimize the radiation performance and radiation directivity and determine the layout and shape of the subsequent parts of the antenna structure. In the case of a limited PCB board area, this width is maintained to obtain a wider bandwidth, and at the same time, enough area is left to ensure that the subsequent wiring length of the antenna is sufficient to be adjusted to the required operating frequency band; the relative distance between this wiring and the reference ground is adjustable for optimizing the antenna return loss, radiation efficiency, radiation direction, etc.

[0072] The second antenna end 212 is the last section of the trace structure of this antenna, with a length of approximately 49.41 mm and a width of 2.65 mm. This section of the trace is perpendicular to the 470 MHz antenna body 211 and follows the edge trace of the board. The length of this trace determines the final required operating frequency point. This section of the structure is the main radiation arm of this antenna, approximately parallel to the reference ground trace, with maximum clearance around it, and no metal or other objects are arranged to enable the antenna to obtain the best radiation efficiency. At the same time, it is necessary to consider making the layout design more compact to save costs while optimizing the antenna performance.

[0073] Embodiment 3: It includes a high-frequency PCB main board 5, a radio frequency module 6, and an on-board antenna;

[0074] The on-board antenna on the high-frequency PCB main board 5 is a 915 MHz on-board antenna 31, and a second π-type antenna matching circuit 32 is also integrated on the high-frequency PCB main board 5.

[0075] The 915 MHz on-board antenna 31 includes a 915 MHz antenna body 311. A third antenna end 312 and a third feed line stub 313 are respectively connected to both ends of the 915 MHz antenna body 311, and the second π-type antenna matching circuit 32 is connected to the third feed line stub 313.

[0076] The radio frequency module 6 of the PCB main board 5 in this embodiment includes a radio frequency transceiver circuit, including a transmitting module and a receiving module, which is connected to the 915 MHz on-board antenna 31 to achieve wireless communication functions. The second π-type antenna matching circuit 32 is an impedance matching circuit reserved for the antenna in the hardware layout and is a part of the on-board antenna. It adjusts the antenna through series and parallel inductors and capacitors to obtain better impedance matching and a wider operating bandwidth.

[0077] Clearance is made around the 915 MHz antenna body 311, the third antenna end 312, and the third feed line stub 313 to ensure the radiation efficiency of the antenna.

[0078] The second π-shaped antenna matching circuit 32 includes a second parallel matching bit a314, a second series matching bit 315, and a second parallel matching bit b316. The antenna is adjusted by series and parallel inductors and capacitors, which is used to assist in optimizing the antenna performance on the basis of the on-board antenna trace debugging, so as to obtain better impedance matching and a wider operating bandwidth. Among them, the second parallel matching bit a314 is the matching bit closest to the antenna end and takes effect first. In the embodiment of the present invention, the operating frequency band of the antenna is 915Mhz. This matching bit can shunt an inductor according to the position on the SMITH chart to make the required frequency point rotate counterclockwise around the constant conductance circle, adjust the size of the inductor so that it intersects the r = 1 circle in the first quadrant, and then connect a capacitor in series with the second series matching bit 315 to make the required frequency point move counterclockwise along the r = 1 circle, adjust the size of the capacitor until it reaches the best matching position of 50 ohms at the center of the chart. For the single-frequency operating frequency band of the embodiment of the present invention, the matching scheme used is not unique, and the optimal matching circuit can be selected according to actual debugging. In this example, the required operating frequency band is relatively high. According to the calculation of the quarter wavelength of the antenna, the required antenna trace area is relatively small. Therefore, on the premise of ensuring the clearance, the common area of the reference ground is slightly increased in this embodiment to improve the radiation efficiency of the eigenmode, and the area occupied by the antenna is relatively reduced. Matching debugging is added for optimization, and finally the best performance is debugged.

[0079] The third feed line stub 313 has a line length of 8.88mm and a line width of 2mm. It is led out from the 3.1 radio frequency module, passes through the second π-shaped antenna matching circuit 32, and routes to the clearance area at the edge of the board. At the beginning of the design of this structure, the hardware layout is made as compact as possible, which can save the PCB area to save costs, and can also squeeze out a larger clearance area for the on-board antenna. The third feed line stub 313 routes to the edge of the PCB board with a length of 8.88mm, which determines the overall antenna layout and the overall trace shape. It can be adjusted according to the actual size of the PCB board and the environmental clearance. In the embodiment of the present invention, it routes in the opposite direction to the reference ground and reaches the edge of the board structure to obtain a larger clearance and better antenna radiation directivity. Since in this embodiment, the antenna environment is relatively friendly to the length of about a quarter wavelength required for the operating frequency band of the antenna 915Mhz, the clearance in the area where the antenna is located is large, and the area of the reference ground is relatively large. Therefore, if the antenna does not have a complex trace, the transmission performance will be lost and the efficiency will decrease.

[0080] The 915Mhz antenna body 311 and the third antenna end 312 are an integral straight trace. The two are integrally formed, with a length of 48.75 mm and a width of 2 mm. It is the last trace structure of this antenna. This trace is led out by the third feed section 313 and is perpendicular to the third feed section 313. It follows the edge trace of the board. The length of this trace determines the final required operating frequency point. This section of the structure is the main radiation arm of this antenna. It is approximately parallel to the reference ground trace, and maximum clearance is made around it without arranging any metal or other objects, so that the antenna can obtain the best radiation efficiency. At the same time, it is necessary to consider making the layout design more compact to save costs while optimizing the antenna performance.

[0081] At the same time, the content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0082] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0083] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wireless smoke detector transceiver device, characterized in that, It includes a structural upper shell, a structural middle shell and a structural bottom shell, and the structural upper shell and the structural bottom shell are respectively installed on the upper and lower surfaces of the structural middle shell through bolts. A structural middle shell bracket is provided at the top of the structural middle shell, and a PCB main board is installed on the structural middle shell bracket through a groove. The PCB main board is integrated with a radio frequency module and an on-board antenna, and the on-board antenna is directly etched on the PCB main board. The PCB main board is also integrated with a function module, and the function module is composed of a control module, a smoke sensing module, a buzzer module, a wireless communication module, a battery power supply module and a battery switch module. An indicator light and a key are provided on the structural upper shell.

2. A multi-specification on-board antenna main board that is easy to replace, comprising the PCB main board, radio frequency module, and on-board antenna described in claim 1, characterized in that: The PCB main board includes three types: low frequency band, middle frequency band and high frequency band, and the low frequency band, middle frequency band and high frequency band respectively refer to the 470 - 510Mhz frequency band, 862 - 870Mhz frequency band, and 902 - 928Mhz frequency band.

3. The multi-specification on-board antenna main board that is easy to replace according to claim 2, characterized in that: The on-board antenna on the PCB main board in the low frequency band is a 470Mhz on-board antenna, and a first π-type antenna matching circuit is also integrated on the PCB main board in the low frequency band.

4. The multi-specification on-board antenna main board that is easy to replace according to claim 3, wherein: The 470Mhz on-board antenna includes a 470Mhz antenna body. The two ends of the 470Mhz antenna body are respectively connected with a first antenna end and a short circuit stub. An extension stub is connected to the side between the 470Mhz antenna body and the first antenna end. An antenna width is connected to the side between the 470Mhz antenna body and the short circuit stub, and one end of the antenna width is connected with a first feed stub. The first π-type antenna matching circuit is connected to the first feed stub, and the first π-type antenna matching circuit includes a first parallel matching bit a, a first series matching bit and a first parallel matching bit b.

5. The multi-specification on-board antenna main board that is easy to replace according to claim 2, wherein: The on-board antenna on the PCB main board in the middle frequency band is an 868Mhz on-board antenna. The 868Mhz on-board antenna includes a 470Mhz antenna body. The two ends of the 470Mhz antenna body are respectively connected with a second antenna end and a second feed stub.

6. The multi-specification on-board antenna main board that is easy to replace according to claim 2, characterized in that: The on-board antenna on the PCB main board in the high frequency band is a 915Mhz on-board antenna, and a second π-type antenna matching circuit is also integrated on the PCB main board in the high frequency band.

7. The multi-specification on-board antenna main board which is easy to replace according to claim 6, characterized in that: The 915Mhz on-board antenna includes a 915Mhz antenna body. The two ends of the 915Mhz antenna body are respectively connected with a third antenna end and a third feed stub. The second π-type antenna matching circuit is connected to the third feed stub, and the second π-type antenna matching circuit includes a second parallel matching bit a, a second series matching bit and a second parallel matching bit b.

8. A replaceable multi-specification on-board antenna main board according to claim 2, characterized in that: The battery switch module is divided into a separation fault detection switch and a power supply switch. It is used as a separation detection switch when applied in the low frequency band, and as a power supply switch when applied in the middle frequency band and the high frequency band.

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