Microstrip patch antenna based on UWB module

Abstract

The invention discloses a microstrip patch antenna based on a UWB module, and relates to the technical field of UWB antennae, and the microstrip patch antenna comprises a substrate composed of a dielectric plate and a PCB, and the substrate is provided with a first surface and a second surface opposite to the first surface; the first surface of the substrate is provided with a conductor patch; a grounding plate is arranged on the second surface of the substrate; the conductor patch is of a second-order regular octagonal fractal structure obtained through two times of iteration of a regular octagonal structure with the side length being R. On the premise that the precision and the transmission distance are guaranteed, the antenna size and the UWB module size can be reduced, the UWB distance measurement module has the advantages of being small in size and high in distance measurement precision, and the UWB distance measurement efficiency is improved. Meanwhile, better omni-directivity and larger gain are achieved, the bandwidth requirement of multiple channels can be met, the performance requirement can be met only through two times of iteration, the requirement for machining precision is low, and implementation is easy.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-wideband antennas, and in particular to a microstrip patch antenna based on a UWB module. Background Art

[0002] Systems based on ultra-wideband technology can transmit extremely short pulse signals of about 10-10000ps. The signals can be transmitted over a wide frequency range. A significant advantage of ultra-wideband systems is that they have the possibility of carrying a large amount of signal data, and based on the way the signal is propagated, they are robust to interference. Another important feature is safety. The possibility of jamming of ultra-wideband short pulses is very small. It is precisely these characteristics of ultra-wideband technology that make it widely used in TOF ranging, which mainly uses the flight time of the signal between two asynchronous transceivers to measure the distance between nodes.

[0003] UWB systems transmit and receive ultrashort electromagnetic pulses, which means the system has a wide bandwidth and low power, which makes signal detection very difficult. To overcome this difficulty, UWB antennas need to receive all components of the signal spectrum with the same efficiency and cannot introduce significant distortion in the phase of these frequency components. The performance of UWB antennas must remain consistent and predictable throughout the operating bandwidth, which means that the antenna radiation pattern should be as constant as possible throughout the operating bandwidth, must be well matched, and the signal waveform must not be distorted.

[0004] At the same time, with the development of communication equipment, module miniaturization is necessary, and many devices also need miniaturized antennas. In addition, at base stations and device access points, miniaturized antennas help reduce the impact of the surrounding environment on wireless network facilities. In order to achieve the miniaturization of UWB modules, antenna miniaturization has become a design focus, requiring that the design size should not be too large, which greatly increases the difficulty of antenna design and limits performance.

[0005] For example, there is a Chinese patent with publication number CN113036408A, which relates to a Minkowski-like fractal ultra-wideband antenna and a design method thereof, including a dielectric substrate, a radiating unit, a feeding unit and a grounding unit attached to one surface of the dielectric substrate; the radiating unit is a fractal patch formed by at least three iterative fractals; the feeding unit is connected to the bottom of the radiating unit to form a whole; the grounding unit includes two grounding plates, and the two grounding plates are symmetrically arranged on both sides of the feeding unit, and a rectangular groove is opened at the bottom of one grounding plate near the edge of the dielectric substrate. The antenna forms a Minkowski fractal structure after three iterative fractals, which greatly increases the propagation path of the current on the surface of the radiating patch, effectively reduces the resonant frequency, and thus reduces the physical size of the antenna; however, the Chinese patent with publication number CN113036408A has a large number of iterations, the size of the branch end is too small, the processing accuracy is high, and the space area is not fully utilized. Summary of the invention

[0006] In order to solve the problems of low gain and poor omnidirectionality of patch antennas, the present invention proposes a microstrip patch antenna based on a UWB module, which can reduce the antenna size and the size of the UWB module while ensuring accuracy and transmission distance, so that the UWB ranging module has the advantages of miniaturization and high ranging accuracy, while achieving better omnidirectionality and greater gain, and can also meet multiple channel bandwidth requirements. Only two iterations are required to meet the performance requirements, and the processing accuracy requirements are low, which is easy to implement.

[0007] In order to achieve the above object, the present invention adopts the following technical solution: a microstrip patch antenna based on a UWB module, The invention comprises a substrate composed of a dielectric plate and a PCB board, and has a first surface and a second surface opposite to the first surface; the first surface of the substrate is provided with a conductor patch; the second surface of the substrate is provided with a ground plate; The conductor patch is a second-order regular octagonal fractal structure obtained by two iterations of a regular octagonal structure with a side length of R; the first iteration extends outward from the middle of each side of the regular octagon to a first rectangle with a length of R / 2 and a width of Wb1; the second iteration extends outward from the middle of the long side of each first rectangle to a second rectangle with a length of R / 4 and a width of Wb1 / 2.

[0008] In this technical solution, the self-similarity characteristics of the fractal structure are used to increase the resonance points and broaden the bandwidth to achieve better omnidirectionality and greater gain. The space filling property of the fractal structure is used to reduce the size of the antenna and achieve integration with the UWB module. By digging grooves on the ground plate and adjusting the slot structure of the ground plate, the antenna has a wider bandwidth and meets the different channel requirements of China's UWB radio equipment.

[0009] Preferably, a feeding unit is connected to the conductor patch, and the feeding unit is provided with a rectangular planar microstrip line, the width Wm of the microstrip line is 1.6 mm±0.1 mm, the length L1 of the microstrip line is 2.25 mm±0.1 mm, and the feed line impedance is 50Ω.

[0010] Preferably, the side length R of the regular octagonal structure is 4.6 mm±0.1 mm, and the width Wb1 of the first rectangle is 0.77 mm±0.1 mm.

[0011] Preferably, the second iteration is not performed on the first side of the regular octagon, and the short side of the microstrip line is connected to the first rectangle of the first side.

[0012] Preferably, the grounding plate is rectangular, with a size of 16.5 mm ± 0.1 mm × 1 mm ± 0.1 mm, and six grooves are provided on the grounding plate, including a first groove, a second groove, a third groove, a fourth groove, a fifth groove and a sixth groove, and the six grooves are all rectangular grooves.

[0013] Preferably, the dimensions of the first groove and the sixth groove are 0.75mm±0.1mm×1.25mm±0.1mm, the dimensions of the second groove and the fifth groove are 0.598mm±0.1mm×1mm±0.1mm, the dimensions of the third groove are 0.47mm±0.1mm×5.15mm±0.1mm, and the dimensions of the fourth groove are 0.598mm±0.1mm×0.5mm±0.1mm.

[0014] Preferably, the center of the third groove is equidistant from the two long sides of the grounding plate, and the remaining grooves are all opened on the first long side of the grounding plate. The distance between the first groove and the second groove and the distance between the fifth groove and the sixth groove are both 1mm±0.1mm, the distance between the second groove and the third groove is 2.1mm±0.1mm, the distance between the third groove and the fourth groove is 0.45mm±0.1mm, and the distance between the fourth groove and the fifth groove is 1.8mm±0.1mm.

[0015] Preferably, the size of the substrate is 16.5 mm±0.1 mm×33 mm±0.1 mm, and the total thickness of the substrate is 1.0 mm±0.1 mm.

[0016] Preferably, the size of the dielectric plate is 16.5 mm±0.1 mm×15.8 mm±0.1 mm.

[0017] Preferably, the dielectric constant of the dielectric plate is 3.42, and the dielectric loss is 0.0030.

[0018] The beneficial effects of the present invention are: 1) By combining sampling of regular octagon with fractal structure, the self-similarity of fractal structure is used to increase the resonance point and broaden the bandwidth, thus achieving better omnidirectionality and greater gain; 2) The space filling property of the fractal structure can be used to reduce the size of the antenna, realize the integrated design of the UWB module and antenna, and realize the miniaturization of the module; 3) By digging grooves on the ground plate and adjusting the slot structure of the ground plate, the path of the current on the edge of the slot is changed, so that the antenna can resonate in other frequency bands, thereby making the antenna have a wider bandwidth and meeting the different channel requirements of China's UWB radio equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a front schematic diagram of a microstrip patch antenna based on a UWB module of the present invention.

[0020] Figure 2 It is a schematic diagram of the reverse side of a microstrip patch antenna based on a UWB module of the present invention.

[0021] Figure 3 It is a schematic diagram of a conductor patch of a microstrip patch antenna based on a UWB module of the present invention.

[0022] Figure 4 It is a schematic diagram of a slotted ground plate of a microstrip patch antenna based on a UWB module of the present invention.

[0023] Figure 5 It is a schematic diagram of the formation process of the fractal structure of a microstrip patch antenna based on a UWB module of the present invention.

[0024] Figure 6 This is a curve diagram showing the influence of different Wn2 sizes on the antenna return loss of a microstrip patch antenna based on a UWB module of the present invention.

[0025] Figure 7 This is a return loss curve diagram of a microstrip patch antenna based on a UWB module in this embodiment simulated by HFSS.

[0026] Figure 8 This is a gain curve diagram of a microstrip patch antenna based on a UWB module in this embodiment simulated by HFSS.

[0027] Fig. 9 This is a directional gain diagram of a microstrip patch antenna based on a UWB module in this embodiment simulated by HFSS.

[0028] Figure numerals: dielectric plate 1; conductor patch 2; microstrip line 3; PCB board 4; ground plate 5; first slot 5-1; second slot 5-2; third slot 5-3; fourth slot 5-4; fifth slot 5-5; sixth slot 5-6. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific implementation method described herein is only an optimal embodiment of the present invention, which is only used to explain the present invention and does not limit the scope of protection of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] The concept of ultra-wideband (UWB) was adopted by the US Department of Defense in 1989. This concept involves a series of terms, such as pulse, carrier-free and large relative bandwidth signals. In 1992, the Federal Communications Commission (FCC) of the United States stipulated different technical standards and operating restrictions for three types of ultra-wideband systems, and increased their frequency range from 3.1GHz to 10.6GHz. The FCC also stipulates that ultra-wideband antennas or ultra-wideband systems must have a bandwidth greater than 500MHz. Systems based on ultra-wideband technology can transmit extremely short pulse signals of about 10~10000ps, and the signals can be propagated over a wide frequency range. A significant advantage of ultra-wideband systems is that they have the possibility of carrying a large amount of signal data, and based on the propagation mode of the signal, they are robust to interference. Another important feature is safety. The possibility of jamming of ultra-wideband short pulses is very small. It is precisely based on these characteristics of ultra-wideband technology that it is widely used in TOF ranging, mainly using the flight time of the signal between two asynchronous transceivers to measure the distance between nodes.

[0031] There are three main solutions for UWB module antenna design in the prior art. The first is to design the antenna and module separately, that is, the module does not contain the antenna; the second is to use a standard ceramic patch antenna design; and the third is to implement it by layout on the module's PCB.

[0032] In the first solution, application developers need to design antennas separately. Due to the requirements of the UWB ranging system, the UWB module and antenna should be a whole. There are differences between individual antennas. Due to the differences in individual antennas, large ranging errors will occur. Therefore, the module cannot implement delay calibration in advance. The application developer needs to complete the antenna design and implement antenna delay calibration. This solution is difficult to design and may result in poor ranging accuracy. It requires professional RF skills and professional instrument testing. The hardware debugging process often requires a lot of time and effort, and the hardware labor cost is high.

[0033] The second solution can effectively reduce the design size of the module. However, since ceramic antennas have certain requirements for patch packaging and size layout, they cannot be fully adapted to all module designs. In addition, standard ceramic antenna designs on the market are generally designed to be compatible with all frequency bands, resulting in a decrease in the overall antenna gain and omnidirectional performance.

[0034] In the third solution, the UWB module antenna is too large to achieve module miniaturization, or the omnidirectionality and gain are poor, resulting in poor anti-multipath capability of the product and ultimately poor ranging accuracy, limited transmission range, and small coverage range under the conditions of a certain number of devices.

[0035] Example 1 This embodiment provides a microstrip patch antenna based on a UWB module. The microstrip patch antenna design is completed on the PCB board of the UWB module. The microstrip line feeding method is adopted, which can reduce the size of the antenna, realize the integration and miniaturization of the UWB module and the antenna, and can achieve better omnidirectionality and greater gain, and can simultaneously meet the different channel requirements of China's UWB radio equipment. An integrated omnidirectional ultra-wideband antenna design is realized.

[0036] A microstrip patch antenna based on a UWB module in this embodiment includes a substrate, a conductor antenna, a feeding unit and a ground plane.

[0037] Among them, the substrate is composed of a dielectric board and a PCB board. The dielectric board is the area where the antenna part is located. The conductor patch and the microstrip line are both arranged on the first surface of the dielectric board. The node is arranged on the second surface of the dielectric board, located at the junction of the dielectric board and the PCB board. The PCB board is the circuit layout area, and the circuit structure of the module is arranged in this area.

[0038] In this embodiment, the size of the substrate is 16.5 mm×33 mm, of which the size of the dielectric board is 16.5 mm×15.8 mm, and the remaining space is the PCB board for wiring the functional circuits.

[0039] The total thickness of the substrate design is 1.0 mm, the dielectric constant is 3.42, the dielectric loss is 0.0030, and the feed line impedance is 50Ω.

[0040] The conductor patch is a second-order regular octagonal fractal structure obtained by two iterations of a regular octagonal structure with a side length of R. By combining the regular octagon with the fractal structure, the self-similarity of the fractal structure is used to increase the resonance point and broaden the bandwidth, and the space filling property of the fractal structure is used to reduce the antenna size, thereby realizing the miniaturization design of the module antenna.

[0041] Preferably, considering the miniaturization requirement and the impact of PCB board processing accuracy and processing technology on cost, two iterations of the fractal structure are optimal. Continuing iterations will result in a smaller size, higher processing accuracy requirements, and no further performance improvement, resulting in a low cost-performance ratio.

[0042] In the first iteration, a first rectangle with a length of R / 2 and a width of Wb1 is extended outward from the middle of each side of the regular octagon to obtain a first-order regular octagon fractal structure; In the second iteration, a second rectangle with a length of R / 4 and a width of Wb1 / 2 is extended outward from the middle of the long side of each first rectangle to obtain a second-order regular octagonal fractal structure.

[0043] There are many unequal patch edges on the edges of the fractal structure, which increases the current propagation path. When the antenna starts working, the different current paths generated by these similar structures interact with each other to produce different resonance points. The interaction between these resonance frequency points gradually increases the radiation resistance of the antenna and gradually decreases the resonance frequency, so the fractal antenna has a broadband characteristic.

[0044] The formation process of fractal structure is described in detail below. Figure 5 shown.

[0045] In the first iteration, the side length of the regular octagon is divided into 4 equal parts, and the middle 2 equal parts are used as the length to form the first rectangular block with a width of Wb1.

[0046] The second iteration is performed by dividing the length of the top edge of the figure of the first iteration into 4 equal parts, and then using the middle 2 equal parts as the length to form a second rectangular block with a width of Wb1 / 2.

[0047] The final fractal structure is formed through secondary iterations, and the fractal structure is combined with a regular octagon. The self-similarity and space-filling properties of the fractal structure are further utilized to increase the resonance points, broaden the bandwidth, and increase the effective electrical path length to reduce the size of the antenna, thereby achieving ultra-wideband, omnidirectional, high-gain and miniaturized antenna design.

[0048] In this embodiment, the conductor patch is fractally designed based on a regular octagon with a side length of R=4.6 mm, making full use of the spatial area, increasing the effective electrical path length of the antenna in a given small area, and achieving the performance of a large-size antenna with a small size.

[0049] The fractal structure adopts a rectangle, which is not only easy to combine with a regular octagonal structure, but also the rectangular fractal structure is easier to generate.

[0050] The first rectangle adopts a length of R / 2, which does not require high requirements on the processing accuracy of the PCB board, is easy to achieve mass production, and has low processing costs.

[0051] The feeding unit connected to the conductor patch is a microstrip line with a width of Wm=1.6mm and a length of L1=2.25mm, and the feed line impedance is 50Ω.

[0052] The grounding plate is provided with a plurality of slots. By making slots at different positions of the grounding plate and changing the size of the slots, the adaptive impedance and return loss of the antenna can be adjusted and optimized.

[0053] In this embodiment, six rectangular grooves are provided on the ground plate, such as Figure 5 As shown, they are the first slot 5-1, the second slot 5-2, the third slot 5-3, the fourth slot 5-4, the fifth slot 5-5 and the sixth slot 5-6, and their corresponding slot sizes are Ln1×Wn1, Ln2×Wn2, Ln3×Wn3, Ln4×Wn4, Ln5×Wn5, Ln6×Wn6.

[0054] The dimensions of the first groove and the sixth groove are 0.75 mm×1.25 mm, the dimension of the second groove is 0.598 mm×1.1 mm, the dimension of the third groove is 0.47 mm×5.15 mm, the dimension of the fourth groove is 0.598 mm×0.5 mm, and the dimension of the fifth groove is 0.598 mm×1 mm.

[0055] The cross section of the ground plate is rectangular, including two long sides and two short sides. The two long sides include a first long side and a second long side opposite to the first long side. The second long side is arranged on the boundary line between the dielectric plate and the PCB board.

[0056] The center of the third groove is located at the midpoint of the short side, that is, the center of the third groove is equidistant from the two long sides of the grounding plate, and the remaining five grooves are all rectangular grooves sunken inward from the first long side.

[0057] In this embodiment, the first groove and the sixth groove are both opened from the edge of the grounding plate, that is, the first groove is located at the first short side, and the sixth groove is located at the second short side. The distance between the first groove and the second groove is 0.95mm, the distance between the second groove and the third groove is 2.05mm, the distance between the third groove and the fourth groove is 0.45mm, the distance between the fourth groove and the fifth groove is 1.8mm, and the distance between the fifth groove and the sixth groove is 1mm.

[0058] By setting the slot size as described above, it is finally achieved that the antenna return loss is better than -12dB in channel 5 at 6.5GHz and channel 9 at 8GHz.

[0059] By adjusting the slot structure of the docking floor, the path of the current on the edge surface of the slot is changed, so that the antenna resonates in other frequency bands, thereby making the antenna have a wider bandwidth.

[0060] The ground plate is made of metal. On the limited metal ground plate, a variety of small-sized slots are opened, and different size combinations of the slots are adjusted to achieve miniaturization of the antenna size and meet good antenna return loss performance requirements.

[0061] Example 2 This embodiment provides a microstrip patch antenna based on a UWB module. The microstrip patch antenna design is completed on the PCB board of the UWB module. The microstrip line feeding method is adopted, which can reduce the size of the antenna, realize the integration and miniaturization of the UWB module and the antenna, and can achieve better omnidirectionality and greater gain, and can simultaneously meet the different channel requirements of China's UWB radio equipment. An integrated omnidirectional ultra-wideband antenna design is realized.

[0062] A microstrip patch antenna based on a UWB module in this embodiment includes a substrate, a conductor antenna, a feeding unit and a ground plane.

[0063] Among them, the substrate is composed of a dielectric board and a PCB board. The dielectric board is the area where the antenna part is located. The conductor patch and the microstrip line are both arranged on the first surface of the dielectric board. The node is arranged on the second surface of the dielectric board, located at the junction of the dielectric board and the PCB board. The PCB board is the circuit layout area, and the circuit structure of the module is arranged in this area.

[0064] In this embodiment, the size of the substrate is 16.5 mm×33 mm, of which the size of the dielectric board is 16.5 mm×15.8 mm, and the remaining space is the PCB board for wiring the functional circuits.

[0065] The total thickness of the substrate design is 1.0 mm, the dielectric constant is 3.42, the dielectric loss is 0.0030, and the feed line impedance is 50Ω.

[0066] The conductor patch is a second-order regular octagonal fractal structure obtained by two iterations of a regular octagonal structure with a side length of R. By combining the regular octagon with the fractal structure, the self-similarity of the fractal structure is used to increase the resonance point and broaden the bandwidth, and the space filling property of the fractal structure is used to reduce the antenna size, thereby realizing the miniaturization design of the module antenna.

[0067] Preferably, considering the miniaturization requirement and the impact of PCB board processing accuracy and processing technology on cost, two iterations of the fractal structure are optimal. Continuing iterations will result in a smaller size, higher processing accuracy requirements, and no further performance improvement, resulting in a low cost-performance ratio.

[0068] In the first iteration, a first rectangle with a length of R / 2 and a width of Wb1 is extended outward from the middle of each side of the regular octagon to obtain a first-order regular octagon fractal structure; In the second iteration, a second rectangle with a length of R / 4 and a width of Wb1 / 2 is extended outward from the middle of the long side of each first rectangle to obtain a second-order regular octagonal fractal structure.

[0069] There are many unequal patch edges on the edges of the fractal structure, which increases the current propagation path. When the antenna starts working, the different current paths generated by these similar structures interact with each other to produce different resonance points. The interaction between these resonance frequency points gradually increases the radiation resistance of the antenna and gradually decreases the resonance frequency, so the fractal antenna has a broadband characteristic.

[0070] The formation process of fractal structure is described in detail below. Figure 5 shown.

[0071] In the first iteration, the side length of the regular octagon is divided into 4 equal parts, and the middle 2 equal parts are used as the length to form the first rectangular block with a width of Wb1.

[0072] The second iteration is performed by dividing the length of the top edge of the figure of the first iteration into 4 equal parts, and then using the middle 2 equal parts as the length to form a second rectangular block with a width of Wb1 / 2.

[0073] The final fractal structure is formed through secondary iterations, and the fractal structure is combined with a regular octagon. The self-similarity and space-filling properties of the fractal structure are further utilized to increase the resonance points, broaden the bandwidth, and increase the effective electrical path length to reduce the size of the antenna, thereby achieving ultra-wideband, omnidirectional, high-gain and miniaturized antenna design.

[0074] In this embodiment, the conductor patch is fractally designed based on a regular octagon with a side length of R=4.6 mm, making full use of the spatial area, increasing the effective electrical path length of the antenna in a given small area, and achieving the performance of a large-size antenna with a small size.

[0075] The fractal structure adopts a rectangle, which is not only easy to combine with a regular octagonal structure, but also the rectangular fractal structure is easier to generate.

[0076] The first rectangle adopts a length of R / 2, which does not require high requirements on the processing accuracy of the PCB board, is easy to achieve mass production, and has low processing costs.

[0077] The feeding unit connected to the conductor patch is a microstrip line with a width of Wm=1.6mm and a length of L1=2.25mm, and the feed line impedance is 50Ω.

[0078] The grounding plate is provided with a plurality of slots. By making slots at different positions of the grounding plate and changing the size of the slots, the adaptive impedance and return loss of the antenna can be adjusted and optimized.

[0079] In this embodiment, six rectangular grooves are provided on the ground plate, such as Figure 5As shown, they are the first slot 5-1, the second slot 5-2, the third slot 5-3, the fourth slot 5-4, the fifth slot 5-5 and the sixth slot 5-6, and their corresponding slot sizes are Ln1×Wn1, Ln2×Wn2, Ln3×Wn3, Ln4×Wn4, Ln5×Wn5, Ln6×Wn6.

[0080] The dimensions of the first groove and the sixth groove are 0.75 mm×1.25 mm, the dimensions of the second groove and the fifth groove are 0.598 mm×1 mm, the dimensions of the third groove are 0.47 mm×5.15 mm, and the dimensions of the fourth groove are 0.598 mm×0.5 mm.

[0081] The cross section of the ground plate is rectangular, including two long sides and two short sides. The two long sides include a first long side and a second long side opposite to the first long side. The second long side is arranged on the boundary line between the dielectric plate and the PCB board.

[0082] The center of the third groove is located at the midpoint of the short side, that is, the center of the third groove is equidistant from the two long sides of the grounding plate, and the remaining five grooves are all rectangular grooves sunken inward from the first long side.

[0083] In this embodiment, the first groove and the sixth groove are both opened from the edge of the grounding plate, that is, the first groove is located at the first short side, and the sixth groove is located at the second short side. The distance between the first groove and the second groove and the distance between the fifth groove and the sixth groove are both 1mm, the distance between the second groove and the third groove is 2.1mm, the distance between the third groove and the fourth groove is 0.45mm, and the distance between the fourth groove and the fifth groove is 1.8mm.

[0084] By setting the slot size as described above, it is finally achieved that the antenna return loss is better than -12dB in channel 5 at 6.5GHz and channel 9 at 8GHz.

[0085] By adjusting the slot structure of the docking floor, the path of the current on the edge surface of the slot is changed, so that the antenna resonates in other frequency bands, thereby making the antenna have a wider bandwidth.

[0086] The ground plate is made of metal. On the limited metal ground plate, a variety of small-sized slots are opened, and different size combinations of the slots are adjusted to achieve miniaturization of the antenna size and meet good antenna return loss performance requirements.

[0087] The antenna return loss performance varies with the slot structure and size, such as Figure 6 The figure shows the effect of different Wn2 sizes on the antenna return loss. When Wn2 is 1mm, the best performance is achieved, and the return loss is better than -12dB.

[0088] Figure 7FIG. 1 is a return loss curve of a microstrip patch antenna based on a UWB module in this embodiment simulated by HFSS. Figure 7 As shown, this embodiment achieves a return loss better than -12 dB in both the required channel 5 and channel 9.

[0089] Figure 8 FIG. 1 is a gain curve diagram of a microstrip patch antenna based on a UWB module in this embodiment in HFSS simulation, as shown in FIG. Figure 8 As shown, this embodiment achieves a gain greater than 4 dBi in both the required channel 5 and the channel 9.

[0090] Fig. 9 This is a directional gain diagram of a microstrip patch antenna based on a UWB module in this embodiment in HFSS simulation, as shown in FIG. Fig. 9 As shown, the directional gain diagram of this embodiment achieves good omnidirectional performance in the required channel 5 (6.5 GHz) and channel 9 (8 GHz) in the Thea 90° plane, and the full-angle gain fluctuation is ±1 dB.

[0091] Although existing microstrip antennas can achieve multi-band and broadband characteristics, the structure of existing antennas is too simple and cannot expand the broadband in multi-bands, so that the performance of the antenna cannot reach the optimal state; the antenna omnidirectionality is poor, which will cause test blind areas when implementing UWB ranging in actual applications and will be easily affected by multipath interference; in addition, it is difficult to achieve miniaturization and integration of antennas with existing technologies.

[0092] The microstrip patch antenna based on the UWB module of the present invention can achieve better omnidirectionality, and can be integrated in the UWB module while meeting the miniaturization requirements of the module and maintaining the high gain and omnidirectional characteristics of a large-size antenna.

[0093] The present invention realizes the design of ultra-wideband antenna through the design of antenna fractal structure. The antenna has a larger bandwidth, the UWB communication frequency band is wide, and it can meet the bandwidth requirements of multiple channels at the same time, especially in channel 5 of 6240~6739.2MHz and channel 9 of 7737.6~8236.8MHz.

Claims

1. A microstrip patch antenna based on a UWB module, characterized in that: The invention comprises a substrate composed of a dielectric plate and a PCB board, and has a first surface and a second surface opposite to the first surface; the first surface of the substrate is provided with a conductor patch; the second surface of the substrate is provided with a ground plate; The conductor patch is a second-order regular octagonal fractal structure obtained by iterating twice a regular octagonal structure with a side length of R; The first iteration extends a first rectangle with a length of R / 2 and a width of Wb1 outward from the middle of each side of the regular octagon; the second iteration extends a second rectangle with a length of R / 4 and a width of Wb1 / 2 outward from the middle of the long side of each first rectangle.

2. A microstrip patch antenna based on a UWB module according to claim 1, characterized in that: The conductor patch is connected to a feeding unit, and the feeding unit is provided with a rectangular planar microstrip line. The width Wm of the microstrip line is 1.6 mm±0.1 mm, the length L1 of the microstrip line is 2.25 mm±0.1 mm, and the feed line impedance is 50Ω.

3. The microstrip patch antenna based on a UWB module according to claim 1, characterized in that: The side length R of the regular octagonal structure is 4.6 mm±0.1 mm, and the width Wb1 of the first rectangle is 0.77 mm±0.1 mm.

4. The microstrip patch antenna based on a UWB module according to claim 2, characterized in that: The second iteration is not performed on the first side of the octagon, and the short side of the microstrip line is connected to the first rectangle of the first side.

5. The microstrip patch antenna based on a UWB module according to claim 1, characterized in that: The cross-section of the grounding plate is rectangular, with a size of 16.5 mm ± 0.1 mm × 1 mm ± 0.1 mm. The grounding plate is provided with six grooves, including a first groove, a second groove, a third groove, a fourth groove, a fifth groove and a sixth groove, and the six grooves are all rectangular grooves.

6. The microstrip patch antenna based on the UWB module according to claim 5, characterized in that: The dimensions of the first groove and the sixth groove are 0.75mm±0.1mm×1.25mm±0.1mm, the dimensions of the second groove and the fifth groove are 0.598mm±0.1mm×1mm±0.1mm, the dimensions of the third groove are 0.47mm±0.1mm×5.15mm±0.1mm, and the dimensions of the fourth groove are 0.598mm±0.1mm×0.5mm±0.1mm.

7. The microstrip patch antenna based on the UWB module according to claim 6, characterized in that: The center of the third groove is equidistant from the two long sides of the grounding plate, and the remaining grooves are all opened on the first long side of the grounding plate. The distance between the first groove and the second groove and the distance between the fifth groove and the sixth groove are both 1mm±0.1mm, the distance between the second groove and the third groove is 2.1mm±0.1mm, the distance between the third groove and the fourth groove is 0.45mm±0.1mm, and the distance between the fourth groove and the fifth groove is 1.8mm±0.1mm.

8. The microstrip patch antenna based on a UWB module according to claim 1, characterized in that: The size of the substrate is 16.5 mm±0.1 mm×33 mm±0.1 mm, and the total thickness of the substrate is 1.0 mm±0.1 mm.

9. The microstrip patch antenna based on a UWB module according to claim 1, characterized in that: The size of the dielectric plate is 16.5 mm±0.1 mm×15.8 mm±0.1 mm.

10. A microstrip patch antenna based on a UWB module according to any one of claims 1 to 9, characterized in that: The dielectric constant of the dielectric plate is 3.42, and the dielectric loss is 0.0030.

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