Waveguide slot antenna

Abstract

The utility model discloses a waveguide slot antenna comprising a feed port layer, a slow wave line layer and a radiation slot layer which are stacked in sequence. The feed port layer is provided with a feed port used for inputting electromagnetic waves or outputting electromagnetic waves. The end face of one end, facing the feed port layer, of the slow wave line layer is provided with a snakelike slow wave cavity, one end of the snakelike slow wave cavity is provided with a feed signal end, and the feed signal end is correspondingly connected with the feed port. A plurality of waveguide radiation slots are formed in the snake-shaped channel of the snake-shaped slow wave cavity at intervals; a plurality of radiation cavity units in one-to-one correspondence with the waveguide radiation slots are arranged on the end face of one end, facing the slow wave line layer, of the radiation slot layer at intervals, a plurality of radiation slots are arranged in the radiation cavity units at intervals, and signal connecting ends correspondingly coupled with the waveguide radiation slots are arranged at one ends of the radiation cavity units. According to the utility model, the scanning angle of the antenna can be increased to adapt to application occasions with high antenna scanning angle requirements, and the adaptability is high.

Description

Technical Field

[0001] This utility model relates to the field of antenna technology, and in particular to a waveguide slot antenna. Background Technology

[0002] A waveguide slot antenna is an antenna with slots cut into the wide or narrow walls of a waveguide, allowing electromagnetic waves propagating in the waveguide to radiate outwards through the slots. This type of antenna is commonly used in the microwave band and can be applied in fields such as communications, radar, and satellite communications.

[0003] Current waveguide slot antennas consist of a feed port layer, a waveguide power divider layer, and a radiating slot layer. The waveguide power divider layer has multiple first waveguide cavities on its end face near the feed port layer. These first waveguide cavities are located directly below the feed port and are used to receive electromagnetic waves transmitted from the feed port. These first waveguide cavities divide the input power into 16 equal parts sequentially in a 1:2, 2:4, 4:8, and 8:16 manner. Each part of the power signal is coupled to the radiating slot layer through its corresponding output port and radiated outwards through the slots in the radiating slot layer. However, while this waveguide power divider structure can improve gain and enable signal monitoring over longer distances, its scanning angle is narrow (approximately 3°), resulting in low adaptability. Increasing the scanning angle requires a larger operating frequency band, which is a significant limitation. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a waveguide slot antenna that can improve the antenna scanning angle to adapt to applications with high antenna scanning angle requirements, and has high adaptability.

[0005] To address the aforementioned technical problems, this utility model provides a waveguide slot antenna, comprising a feed port layer, a slow wave line layer, and a radiating slot layer stacked sequentially. The feed port layer has a feed port for inputting or outputting electromagnetic waves. The slow wave line layer has a serpentine slow wave cavity on one end face facing the feed port layer, and a feed signal terminal is provided at one end of the serpentine slow wave cavity, which is correspondingly connected to the feed port. Multiple waveguide radiating slots are spaced apart in the serpentine channel of the serpentine slow wave cavity. Multiple radiating cavity units are spaced apart on one end face of the radiating slot layer facing the slow wave line layer, each radiating cavity unit corresponding to a waveguide radiating slot. Multiple radiating slots are spaced apart within each radiating cavity unit, and a signal connection terminal correspondingly coupled to a waveguide radiating slot is provided at one end of each radiating cavity unit.

[0006] As an improvement to the above scheme, each straight waveguide segment in the serpentine channel is provided with the waveguide radiation slot, and the serpentine channel is located below the feed signal end.

[0007] As an improvement to the above scheme, the centerline of the straight waveguide segment is staggered from the centerline of its corresponding waveguide radiation slot, and the centerlines of the multiple waveguide radiation slots have different offsets.

[0008] As an improvement to the above scheme, the cross-section of the straight waveguide segment includes the waveguide wide side dimension a and the waveguide narrow side dimension b. The ratio e = d / a of the offset d of the centerline of the waveguide radiation slot to the waveguide wide side dimension a is 0 < e < 0.5. The equivalent conductivity of the waveguide radiation slot increases as the ratio e increases.

[0009] As an improvement to the above scheme, the ratio c = b / a of the narrow side dimension b of the waveguide to the wide side dimension a of the waveguide is 0.2 ≤ c ≤ 0.9.

[0010] As an improvement to the above scheme, the wide side dimension a of the waveguide is 1.37mm≤a≤4mm, the narrow side dimension b of the waveguide is 0.5mm≤b≤3.6mm, and the offset d of the center line of the waveguide radiation slot is 0.005mm≤d≤1.8mm.

[0011] As an improvement to the above scheme, the radiation cavity unit has a plurality of radiation slots spaced upward along the signal connection end, and two adjacent radiation slots are staggered and arranged on both sides of the vertical center line of the radiation cavity unit.

[0012] As an improvement to the above scheme, a coupling layer is provided between the feed port layer and the slow wave line layer. The coupling layer is provided with a coupling port corresponding to the feed port, and the coupling port is connected to the feed port and the feed signal terminal respectively.

[0013] As an improvement to the above scheme, the other end of the serpentine slow wave cavity is provided with a signal discharge port, and both the power supply port layer and the coupling layer are provided with discharge ports corresponding to and connected to the signal discharge port.

[0014] As an improvement to the above scheme, the end of the radiation cavity unit away from the signal connection terminal is provided with a first vent hole, and the feed port layer, the slow wave line layer and the coupling layer are all provided with second vent holes that correspond one-to-one with the first vent hole.

[0015] The beneficial effects of implementing this utility model are as follows:

[0016] This utility model has a simple structure, consisting of multiple stacked layered plates, which facilitates production, processing, and installation. The constructed slow-wave line structure can improve the antenna gain, thereby increasing the antenna scanning angle within a limited operating frequency band. This makes it suitable for applications with high antenna scanning angle requirements, demonstrating high adaptability. Attached Figure Description

[0017] Figure 1 This is an exploded structural diagram of the waveguide slot antenna of this utility model;

[0018] Figure 2 This is a schematic diagram of the reverse structure of the slow wave line layer of this utility model;

[0019] Figure 3 This is a schematic diagram of the front structure of the slow wave line layer of this utility model;

[0020] Figure 4 This is a schematic diagram of the reverse structure of the radiation slit layer of this utility model;

[0021] Figure 5 This is a front structural diagram of the radiation gap layer of this utility model;

[0022] Figure 6 This is a schematic diagram of the front structure of the power supply port layer of this utility model;

[0023] Figure 7 This is a front structural diagram of the coupling layer of this utility model;

[0024] Figure 8 This is a partial structural schematic diagram of the linear waveguide section of this utility model;

[0025] Figure 9 This is a graph showing the offset of the waveguide radiation slot of this utility model versus its equivalent conductivity.

[0026] Figure 10 This is the normalized electromagnetic wave pattern of Embodiment 1 of the serpentine slow-wave plate of this utility model;

[0027] Figure 11 This is the normalized electromagnetic wave pattern of Embodiment 2 of the serpentine slow-wave plate of this utility model;

[0028] Figure 12 This is the normalized electromagnetic wave pattern of Embodiment 3 of the serpentine slow-wave plate of this utility model;

[0029] Figure 13 This is the normalized electromagnetic wave pattern of Embodiment 4 of the serpentine slow-wave plate of this utility model;

[0030] Figure 14 This is the normalized electromagnetic wave pattern of Comparative Example 1 of the serpentine slow-wave plate of this utility model.

[0031] Figure 15 This is the normalized electromagnetic wave pattern of Comparative Example 2 of the serpentine slow-wave plate of this utility model. Detailed Implementation

[0032] To make the objectives, technical solutions and advantages of this utility model clearer, the utility model will be described in further detail below with reference to the accompanying drawings.

[0033] like Figures 1 to 6 As shown, a specific embodiment of this utility model provides a waveguide slot antenna, including a feed port layer 1, a slow wave line layer 2, and a radiation slot layer 3 stacked sequentially. A series-fed frequency-sweep array antenna structure is constructed using the feed port layer 1, the slow wave line layer 2, and the radiation slot layer 3. The feed port layer 1 has a feed port 11 for inputting or outputting electromagnetic waves. The feed port 11 can be fed via a transmission line, waveguide, or resonant cavity. The slow wave line layer 2 has a serpentine slow wave cavity 21 on one end facing the feed port layer 1. One end of the serpentine slow wave cavity 21 has a feed signal terminal 22, which is connected to the feed port 11 to achieve battery wave transmission. Multiple waveguide radiation slots 24 are spaced apart in the serpentine channel 23 of the serpentine slow wave cavity 21. The radiation slot layer 3 has multiple radiation cavity units 31 spaced apart on one end face facing the slow wave line layer 2. Each radiation cavity unit 31 is arranged in a one-to-one correspondence with a waveguide radiation slot 24, that is, each waveguide radiation slot 24 is equipped with a radiation cavity unit 31. Multiple radiation slots 32 are spaced apart inside each radiation cavity unit 31. One end of each radiation cavity unit 31 is provided with a signal connection terminal 33 that is coupled to the waveguide radiation slot 24 to realize electromagnetic wave transmission.

[0034] When the antenna transmits a signal, the external antenna control device connects to the feed port 11 and sends a signal. The electromagnetic wave is transmitted through the feed port 11 to the feed signal terminal 22 on the slow wave line layer 2 and propagates along the serpentine channel 23 of the serpentine slow wave cavity 21. When the electromagnetic wave flows through each waveguide radiation slot 24, part of the electromagnetic wave signal is coupled to the corresponding signal connection terminal 33 through the waveguide radiation slot 24. The electromagnetic wave flows through the signal connection terminal 33 in the radiation cavity unit 31 and is emitted externally through multiple radiation slots 32 in the radiation cavity unit 31. Conversely, when the antenna receives a signal, it receives the electromagnetic wave through the radiation cavity unit 31, and then the electromagnetic wave is transmitted sequentially to the feed port 11 in the opposite direction, and finally transmitted to the antenna control device.

[0035] Specifically, the serpentine slow-wave line structure of this invention uses a series-fed frequency sweep array as its feeding method. This serpentine slow-wave line structure allows for precise pointing of the main beam of the antenna array's radiation pattern. Within the limited operating frequency band of the antenna array, the offset angle (i.e., the scanning angle) can be increased by adjusting the feeding frequency. This allows it to adapt to applications with high antenna scanning angle requirements without requiring a large input operating frequency band, demonstrating high adaptability. Furthermore, this invention is constructed from multiple stacked layered structures, facilitating manufacturing and installation. Specifically, this invention achieves a scanning angle of up to 16° in the 79GHz-81GHz frequency band, meeting the corresponding antenna scanning angle requirements of various applications.

[0036] Specifically, such as Figure 2 and Figure 4 As shown, the serpentine channel 23 includes several straight waveguide segments 231 and connecting waveguide segments 232. A gap is left between two adjacent straight waveguide segments 232 to separate them and prevent signal interference. Two adjacent straight waveguide segments 2321 are connected by the connecting waveguide segments 232 to construct a slow waveline structure. Each straight waveguide segment 231 and its adjacent connecting waveguide segment 232 constitute a waveguide unit.

[0037] Each straight waveguide segment 231 in the serpentine channel 23 is provided with a waveguide radiation slot 24, and the serpentine channel 23 is located below the feed signal terminal 22. The radiating cavity unit 31 has at least one radiation slot 32 corresponding to the region of the serpentine channel 23, and this radiation slot 32 is close to the signal connection terminal 33. In actual operation, electromagnetic waves flowing through the straight waveguide segment 231 are coupled to the signal connection terminal 33 of the radiating cavity unit 31 via the waveguide radiation slot 24, so that the electromagnetic waves are emitted outward through the radiating cavity unit 31; conversely, electromagnetic waves received by the radiating cavity unit 31 are also coupled into the serpentine channel 23 and flow along the serpentine channel 23 towards the feed signal terminal 22. Preferably, each connecting waveguide segment 232 in the serpentine channel 23 is a 180-degree circular arc connecting waveguide segment, which can correspondingly reduce the voltage standing wave ratio (VSWR) of the serpentine waveguide, and correspondingly increase the antenna gain and reduce dissipation, thereby improving the stability of the antenna circuit. The shape of the connecting waveguide segment 232 is not limited to this; it can also be a rectangular connecting waveguide segment or a semi-circular or semi-rectangular connecting waveguide segment, etc.

[0038] Preferably, such as Figures 4 to 5 As shown, the radiation cavity unit 31 has a plurality of radiation slots 32 arranged at intervals along the signal connection end 33. Two adjacent radiation slots 32 are staggered on both sides of the vertical center line of the radiation cavity unit 31 to improve the radiation and reception effect of electromagnetic waves.

[0039] Preferably, such as Figure 1 and 7As shown, a coupling layer 4 is provided between the feed port layer 1 and the slow wave line layer 2. The coupling layer 4 is provided with a coupling port 41 corresponding to the feed port 11. The coupling port 41 is connected to the feed port 11 and the feed signal terminal 22 respectively to realize the coupling transmission of electromagnetic waves.

[0040] Furthermore, such as Figure 2 , 3 As shown in Figures 6 and 7, the other end of the serpentine slow-wave cavity 21 is provided with a signal discharge port 25. Both the feed port layer 1 and the coupling layer 4 are provided with discharge ports 5 corresponding to the signal discharge port 25. When the antenna transmits electromagnetic waves, the electromagnetic waves will flow into the serpentine channel through the feed signal end 22. On the one hand, the electromagnetic wave signal is coupled to the radiation cavity unit 31 through the waveguide radiation gap 24 of the serpentine channel, realizing the outward radiation of the electromagnetic wave signal. On the other hand, the excess or excessive electromagnetic wave energy in the serpentine channel 23 is discharged outward through the discharge port 5 of the feed port layer 1 through the signal discharge port 25, and finally received by the corresponding external receiving device.

[0041] Furthermore, such as Figure 2 , 3 As shown in Figures 4, 6, and 7, the end of the radiating cavity unit 31 furthest from the signal connection terminal 33 is provided with a first venting hole 34. The feed port layer 1, the slow wave line layer 2, and the coupling layer 4 are each provided with a second venting hole 6 corresponding to the first venting hole 34. When the antenna transmits electromagnetic waves, the electromagnetic waves are coupled to the signal connection terminal 33 of the radiating cavity unit 31 through the waveguide radiation gap 24. Then, the electromagnetic waves flow upwards from the signal connection terminal 33. On the one hand, the electromagnetic waves are radiated outwards through the radiation gap 32 on the radiating cavity unit 31; on the other hand, excess or excessive electromagnetic wave energy is discharged outwards through the first venting hole 34 and multiple second venting holes 6, finally being received by the corresponding external receiving device.

[0042] Preferably, the waveguide radiation slot 24 and the radiation slot 32 have the same shape.

[0043] In summary, this utility model has a simple structure, consisting of multiple stacked layered plates, which facilitates production, processing, and installation. The constructed slow-wave line structure can improve antenna gain, thereby increasing the antenna scanning angle within a limited operating frequency band, making it suitable for applications with high antenna scanning angle requirements and highly adaptable.

[0044] Furthermore, the specific structure of the slow-wave line layer of this utility model will be further described below:

[0045] like Figure 8As shown, the centerline of the straight waveguide segment 231 in the slow wave line layer 2 is offset from the centerline of the corresponding waveguide radiation slot 24 to achieve the offset of the centerline of the waveguide radiation slot 24. By adjusting the offset of the waveguide radiation slot 24, its equivalent conductivity can be increased, thereby increasing the electromagnetic wave energy radiated or coupled to the lower unit, that is, increasing the radiated power, and thus improving the antenna radiation or scanning effect.

[0046] The centerlines of the multiple waveguide radiation slots 24 have different offsets (d) to achieve different required radiation power. By setting the offset of the centerlines of the multiple waveguide radiation slots 24, the slow wave line layer 2 exhibits a radiation effect that is strong in the middle and weak on both sides, thereby improving the antenna scanning effect. When the electromagnetic wave signal radiates outward, it propagates along the serpentine channel 23. Each time the electromagnetic wave signal flows through a waveguide radiation slot 24, part of its electromagnetic wave energy is radiated outward through that slot, while the remaining electromagnetic wave energy continues to flow backward, gradually weakening. By adjusting the offset of the waveguide radiation slots 24 along the direction of the serpentine channel 23, the antenna radiation effect exhibits a radiation waveform that is strong in the middle and weak on both sides, thereby improving the antenna radiation intensity and radiation distance, meeting the user's long-distance antenna scanning requirements.

[0047] Furthermore, the cross-section of the straight waveguide segment 231 includes a wide side dimension a and a narrow side dimension b. The wide side dimension a is the width dimension of the straight waveguide segment 231, and the narrow side dimension b is the depth dimension of the straight waveguide segment 231. The ratio c = b / a of the narrow side dimension b to the wide side dimension a is 0.2 ≤ c ≤ 0.9.

[0048] For example, the ratio c of the narrow side dimension b of the waveguide to the wide side dimension a of the waveguide is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 and 0.9, but is not limited to these. When the ratio c is too large, it is easy to cause the waveguide structure and the overall antenna to be large in size and occupy a lot of space, increasing the structural cost; at the same time, the larger the cross-sectional area of ​​the waveguide, the lower the cutoff frequency will be, affecting the application range of the antenna's operating frequency band.

[0049] Furthermore, the ratio e = d / a of the offset d of the centerline of the waveguide radiation slot 24 to the width dimension a of the waveguide is 0 < e < 0.5, and the equivalent conductivity of the waveguide radiation slot 24 increases as the ratio e increases.

[0050] For example, the ratio e of the offset of the centerline of the waveguide radiation slot 24 to the width dimension of the waveguide is 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45 and 0.49, but it is not limited to this. When the ratio e is too large, it is easy to affect the equivalent conductivity of the waveguide radiation slot 24, reduce the radiation energy of electromagnetic waves, and thus affect the antenna radiation or scanning effect.

[0051] Wherein, the wide side dimension a of the waveguide is 1.37mm≤a≤4mm, the narrow side dimension b of the waveguide is 0.5mm≤b≤3.6mm, and the offset d of the center line of the waveguide radiation slot 24 is 0.005mm≤d≤1.8mm. Within this range, the overall volume of the serpentine slow wave slot 22 is small and can take into account both higher intensity radiation energy and longer scanning distance, resulting in the best overall performance.

[0052] For example, the waveguide wide side dimension a is 1.37mm, 1.50mm, 1.75mm, 2.00mm, 2.25mm, 2.3mm, 2.5mm, 2.75mm, 3.0mm, 3.25mm, 3.75mm or 4.0mm, but is not limited thereto.

[0053] For example, the narrow side dimension b of the waveguide is 0.5mm, 1.00mm, 1.50mm, 2.00mm, 2.5mm, 23.0mm, 3.5mm or 3.6mm, but is not limited thereto.

[0054] For example, the offset d of the centerline of the waveguide radiation slot 24 is 0.005mm, 0.008mm, 0.0010mm, 0.015mm, 0.020mm, 0.025mm, 0.030mm, 0.035mm, 0.040mm, 0.045mm, 0.050, 0.055, 0.060mm, 0.065mm, 0.070mm, 0.075mm, 0.080mm, 0.085mm, 0.090mm, 0.095mm, 0.010mm, 0.050mm, 0.100mm, 0.150mm, 0.200mm, 0.250mm, 0.30mm. 0mm, 0.350mm, 0.400mm, 0.450mm, 0.500mm, 0.550mm, 0.600mm, 0.650mm, 0.700mm, 0.850mm, 0.900mm, 0.950mm, 1.000mm, 1.050mm, 1.100mm, 1.150mm, 1.200mm, 1.250mm, 1.300mm, 1.350mm, 1.400mm, 1.450mm, 1.500mm, 1.550mm, 1.600mm, 1.650mm, 1.700mm, 1.750mm, or 1.800mm, but not limited to these.

[0055] It should be noted that the wavelength range of the electromagnetic wave can be obtained based on the operating frequency range of the antenna application. For example, the operating frequency range of the W-band is 75–110 GHz, corresponding to a wavelength range of approximately 2.73–4 mm, and a half-wavelength range of 1.36–2 mm. That is, given a specific operating frequency, the wavelength of the corresponding electromagnetic wave can be obtained. The waveguide width dimension 'a' is chosen to be greater than half the wavelength (i.e., half the wavelength): a > λ / 2. The waveguide wavelength λ of this waveguide element can be determined using the waveguide width dimension 'a' and the electromagnetic wave wavelength λ. g .like Figure 9 As shown, when the waveguide wide side dimension a, the waveguide narrow side dimension b, the electromagnetic wave wavelength λ, and the waveguide wavelength λ... g When the value of is determined, the larger the ratio of the offset of the center line of the waveguide radiation slot 24 to the width of the waveguide, that is, the larger the offset d of the center line of the waveguide radiation slot 24, the larger the equivalent conductivity of the waveguide radiation slot 24, the greater the radiation energy and radiation power, and the farther the radiation or scanning distance.

[0056] Preferably, the waveguide radiation slot 24 is strip-shaped, and the two ends of the waveguide radiation slot 24 are semi-circular.

[0057] In some embodiments, the length of the straight waveguide segment 231 in the slow waveline layer 2 is 2–25 mm, the width of the straight waveguide segment 231 is 1.37–4 mm, the depth of the straight waveguide segment 231 is 0.5–3.6 mm, the length of the connecting waveguide segment 232 is 1.6–25 mm, and the width of the gap is 0.25–1 mm; the length of the waveguide radiation slot 24 is 1.37–2.5 mm, the width of the waveguide radiation slot 24 is 0.1–0.8 mm, the offset d of the centerline of the waveguide radiation slot 24 is 0.005–1.8 mm, the length of the slow waveline layer 2 is 50–400 mm, and the width of the slow waveline layer 2 is 5–150 mm. Slow-wave line layer and waveguide slot antennas within this range are better suited for use in the W-band (75–110 GHz) operating range. They can radiate electromagnetic waves that are strong in the middle and weak on both sides, and have the characteristics of small overall size, wide radiation range, strong radiation energy and long radiation distance.

[0058] The slow-wave line layer 2 of this utility model will be further described below with reference to the accompanying drawings and embodiments:

[0059] Example 1

[0060] This invention provides a slow-waveline layer 2. One end of the slow-waveline layer 2 facing the feed port layer 1 has a serpentine slow-wave cavity 21. One end of the serpentine slow-wave cavity 21 has a feed signal terminal 22, which is connected to the feed port 11 to achieve battery wave transmission. Multiple waveguide radiation slots 24 are spaced apart in the serpentine channel 23 of the serpentine slow-wave cavity 21. The serpentine channel 23 includes several straight waveguide segments 231 and connecting waveguide segments 232. A gap is left between adjacent straight waveguide segments 231 to separate them and avoid signal interference. Adjacent straight waveguide segments 231 are connected by the connecting waveguide segments 232 to construct a slow-waveline structure. The centerlines of the straight waveguide segments 231 in the slow-waveline layer 2 are staggered from the centerlines of their corresponding waveguide radiation slots 24.

[0061] In this embodiment, the length of the straight waveguide segment 231 is preferably 9.4 mm, the width of the straight waveguide segment 231 (i.e., the wide side dimension a) is 2.3 mm, the depth of the straight waveguide segment 231 (i.e., the narrow side dimension b) is 1.61 mm, the length of the connecting waveguide segment 232 is 4.4 mm, and the width of the gap is 0.5 mm; the length of the waveguide radiation slot 24 is 1.9 mm, the width of the waveguide radiation slot 24 is 0.4 mm, the offset d of the centerline of the waveguide radiation slot 24 is 0.02-0.10 mm, and the offset d of the centerline of the multiple waveguide radiation slots 24 is different. Along the transmission direction of the serpentine channel 23, the offset first increases and then decreases. The length of the slow waveline layer 2 is 184.8 mm, and the width of the slow waveline layer 2 is 15 mm.

[0062] In this embodiment, the ratio c of the narrow side dimension b of the waveguide to the wide side dimension a of the waveguide is 0.7, and the ratio e of the offset d of the center line of the waveguide radiation slot 24 to the wide side dimension a of the waveguide is 0.008≤e≤0.043.

[0063] In this embodiment, the operating frequency is 79-80GHz.

[0064] Example 2

[0065] This invention provides a slow-waveline layer 2. One end of the slow-waveline layer 2 facing the feed port layer 1 has a serpentine slow-wave cavity 21. One end of the serpentine slow-wave cavity 21 has a feed signal terminal 22, which is connected to the feed port 11 to achieve battery wave transmission. Multiple waveguide radiation slots 24 are spaced apart in the serpentine channel 23 of the serpentine slow-wave cavity 21. The serpentine channel 23 includes several straight waveguide segments 231 and connecting waveguide segments 232. A gap is left between adjacent straight waveguide segments 231 to separate them and avoid signal interference. Adjacent straight waveguide segments 231 are connected by the connecting waveguide segments 232 to construct a slow-waveline structure. The centerlines of the straight waveguide segments 231 in the slow-waveline layer 2 are staggered from the centerlines of their corresponding waveguide radiation slots 24.

[0066] The length of the straight waveguide segment 231 is preferably 3 mm, the width (i.e., waveguide wide side dimension a) is 2.3 mm, the depth (i.e., waveguide narrow side dimension b) is 1.61 mm, the length of the connecting waveguide segment 232 is 4.4 mm, and the width of the gap is 0.5 mm; the length of the waveguide radiation slot 24 is 1.9 mm, the width of the waveguide radiation slot 24 is 0.4 mm, and the offset d of the centerline of the waveguide radiation slot 24 is 0.02-0.10 mm. The offset d of the centerline of the multiple waveguide radiation slots 24 is different, and the offset first increases and then decreases along the transmission direction of the serpentine channel 23. The length of the slow waveline layer 2 is 184.8 mm, and the width of the slow waveline layer 2 is 15 mm. It should be noted that when the length of the straight waveguide segment 231 or the connecting reporting segment changes, it will affect the antenna beam scanning pointing angle to a certain extent, reducing the antenna scanning angle.

[0067] In this embodiment, the ratio c of the narrow side dimension b of the waveguide to the wide side dimension a of the waveguide is 0.7, and the ratio e of the offset d of the center line of the waveguide radiation slot 24 to the wide side dimension a of the waveguide is 0.008≤e≤0.043.

[0068] In this embodiment, the operating frequency is 79-80GHz.

[0069] Example 3

[0070] This invention provides a slow-waveline layer 2. One end of the slow-waveline layer 2 facing the feed port layer 1 has a serpentine slow-wave cavity 21. One end of the serpentine slow-wave cavity 21 has a feed signal terminal 22, which is connected to the feed port 11 to achieve battery wave transmission. Multiple waveguide radiation slots 24 are spaced apart in the serpentine channel 23 of the serpentine slow-wave cavity 21. The serpentine channel 23 includes several straight waveguide segments 231 and connecting waveguide segments 232. A gap is left between adjacent straight waveguide segments 231 to separate them and avoid signal interference. Adjacent straight waveguide segments 231 are connected by the connecting waveguide segments 232 to construct a slow-waveline structure. The centerlines of the straight waveguide segments 231 in the slow-waveline layer 2 are staggered from the centerlines of their corresponding waveguide radiation slots 24.

[0071] The length of the straight waveguide segment 231 is preferably 9.4 mm, the width (i.e., the wide side dimension a) of the straight waveguide segment 231 is 2.3 mm, the depth (i.e., the narrow side dimension b) of the straight waveguide segment 231 is 1.61 mm, the length of the connecting waveguide segment 232 is 4.4 mm, and the width of the gap is 0.5 mm; the length of the waveguide radiation slot 24 is 1.9 mm, the width of the waveguide radiation slot 24 is 0.4 mm, the offset d of the centerline of the waveguide radiation slot 24 is 0.07-0.13 mm, and the offset d of the centerline of the multiple waveguide radiation slots 24 is different. Along the transmission direction of the serpentine channel 23, the offset first increases and then decreases. The length of the slow waveline layer 2 is 89.6 mm, and the width of the slow waveline layer 2 is 15 mm. It should be noted that when the length of the slow wave line layer 2 is reduced, in order to retain better performance effects such as antenna gain and sidelobe level, the offset of the center line of the waveguide radiation slot 24 can be adjusted accordingly to adapt to the shorter serpentine slow wave plate.

[0072] In this embodiment, the ratio c of the narrow side dimension b of the waveguide to the wide side dimension a of the waveguide is 0.7, and the ratio e of the offset d of the center line of the waveguide radiation slot 24 to the wide side dimension a of the waveguide is 0.030≤e≤0.056.

[0073] In this embodiment, the operating frequency is 79-80GHz.

[0074] Example 4

[0075] This invention provides a slow-waveline layer 2. One end of the slow-waveline layer 2 facing the feed port layer 1 has a serpentine slow-wave cavity 21. One end of the serpentine slow-wave cavity 21 has a feed signal terminal 22, which is connected to the feed port 11 to achieve battery wave transmission. Multiple waveguide radiation slots 24 are spaced apart in the serpentine channel 23 of the serpentine slow-wave cavity 21. The serpentine channel 23 includes several straight waveguide segments 231 and connecting waveguide segments 232. A gap is left between adjacent straight waveguide segments 231 to separate them and avoid signal interference. Adjacent straight waveguide segments 231 are connected by the connecting waveguide segments 232 to construct a slow-waveline structure. The centerlines of the straight waveguide segments 231 in the slow-waveline layer 2 are staggered from the centerlines of their corresponding waveguide radiation slots 24.

[0076] The length of the straight waveguide segment 231 is preferably 8 mm, the width (i.e., the wide side dimension a) of the straight waveguide segment 231 is 1.96 mm, the depth (i.e., the narrow side dimension b) of the straight waveguide segment 231 is 1.37 mm, the length of the connecting waveguide segment 232 is 3.74 mm, and the width of the gap is 0.425 mm; the length of the waveguide radiation slot 24 is 1.62 mm, the width of the waveguide radiation slot 24 is 0.34 mm, the offset d of the centerline of the waveguide radiation slot 24 is 0.017-0.085 mm, and the offset d of the centerline of the multiple waveguide radiation slots 24 is different. Along the transmission direction of the serpentine channel 23, the offset first increases and then decreases. The length of the slow waveline layer 2 is 157.7 mm, and the width of the slow waveline layer 2 is 12.75 mm.

[0077] In this embodiment, the ratio c of the narrow side dimension b of the waveguide to the wide side dimension a of the waveguide is 0.7, and the ratio e of the offset d of the center line of the waveguide radiation slot 24 to the wide side dimension a of the waveguide is 0.008≤e≤0.043.

[0078] In this embodiment, the operating frequency is 92-93 GHz.

[0079] By proportionally adjusting the parameters of the slow-wave line layer 2, it is possible to adapt to scanning operations in different operating frequency bands and obtain better antenna radiation performance.

[0080] Comparative Example 1

[0081] This invention provides a slow-waveline layer 2. One end of the slow-waveline layer 2 facing the feed port layer 1 has a serpentine slow-wave cavity 21. One end of the serpentine slow-wave cavity 21 has a feed signal terminal 22, which is connected to the feed port 11 to achieve battery wave transmission. Multiple waveguide radiation slots 24 are spaced apart in the serpentine channel 23 of the serpentine slow-wave cavity 21. The serpentine channel 23 includes several straight waveguide segments 231 and connecting waveguide segments 232. A gap is left between adjacent straight waveguide segments 231 to separate them and avoid signal interference. Adjacent straight waveguide segments 231 are connected by the connecting waveguide segments 232 to construct a slow-waveline structure. The centerlines of the straight waveguide segments 231 in the slow-waveline layer 2 are staggered from the centerlines of their corresponding waveguide radiation slots 24.

[0082] In this embodiment, the length of the straight waveguide segment 231 is preferably 9.4 mm, the width of the straight waveguide segment 231 (i.e., the waveguide wide side dimension a) is 2.3 mm, the depth of the straight waveguide segment 231 (the waveguide narrow side dimension b) is 1.61 mm, the length of the connecting waveguide segment 232 is 4.4 mm, and the width of the gap is 0.5 mm; the length of the waveguide radiation slot 24 is 1.9 mm, the width of the waveguide radiation slot 24 is 0.4 mm, the offset d of the centerline of the waveguide radiation slot 24 is 0.05 mm, the length of the slow waveline layer 2 is 184.8 mm, and the width of the slow waveline layer 2 is 15 mm.

[0083] In this embodiment, the ratio c of the narrow side dimension b of the waveguide to the wide side dimension a of the waveguide is 0.7, and the ratio e of the offset d of the centerline of the waveguide radiation slot 24 to the wide side dimension a of the waveguide is 0.021.

[0084] In this embodiment, the operating frequency is 79-80GHz.

[0085] Comparative Example 2

[0086] This invention provides a slow-waveline layer 2. One end of the slow-waveline layer 2 facing the feed port layer 1 has a serpentine slow-wave cavity 21. One end of the serpentine slow-wave cavity 21 has a feed signal terminal 22, which is connected to the feed port 11 to achieve battery wave transmission. Multiple waveguide radiation slots 24 are spaced apart in the serpentine channel 23 of the serpentine slow-wave cavity 21. The serpentine channel 23 includes several straight waveguide segments 231 and connecting waveguide segments 232. A gap is left between adjacent straight waveguide segments 231 to separate them and avoid signal interference. Adjacent straight waveguide segments 231 are connected by the connecting waveguide segments 232 to construct a slow-waveline structure. The centerline of each straight waveguide segment 231 coincides with the centerline of its corresponding waveguide radiation slot 24.

[0087] In this embodiment, the length of the straight waveguide segment 231 is preferably 9.4 mm, the width of the straight waveguide segment 231 (i.e., the waveguide wide side dimension a) is 2.3 mm, the depth of the straight waveguide segment 231 (i.e., the waveguide narrow side dimension b) is 1.61 mm, the length of the connecting waveguide segment 232 is 4.4 mm, and the width of the gap is 0.5 mm; the length of the waveguide radiation slot 24 is 1.9 mm, the width of the waveguide radiation slot 24 is 0.4 mm, the offset d of the centerline of the waveguide radiation slot 24 is 0 mm, the length of the slow waveline layer 2 is 184.8 mm, and the width of the slow waveline layer 2 is 15 mm.

[0088] In this embodiment, the ratio c of the narrow side dimension b of the waveguide to the wide side dimension a of the waveguide is 0.7, and the ratio e of the offset d of the centerline of the waveguide radiation slot 24 to the wide side dimension a of the waveguide is 0.

[0089] In this embodiment, the operating frequency is 79-80GHz.

[0090] The performance of the serpentine slow-wave plates prepared in Examples 1 to 4 and Comparative Examples 1 to 2 was tested, and the results were as follows: Figures 10 to 15 The normalized radiation pattern of the electromagnetic wave shown is presented, and the test results are as follows:

[0091]

[0092] As can be seen from the above test results and the normalized radiation pattern of electromagnetic waves, compared with comparative examples 1 to 2, these embodiments 1 to 4 have lower sidelobe levels and higher antenna gain, and their radiation range and distance are relatively longer, resulting in better electromagnetic wave radiation or scanning effects.

[0093] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications are also considered to be within the protection scope of this utility model.

Claims

1. A waveguide slot antenna, characterized in that, It includes a feed port layer, a slow wave line layer, and a radiation slot layer stacked in sequence; The feed port layer is provided with feed ports for inputting electromagnetic waves or outputting electromagnetic waves. The slow wave line surface is provided with a serpentine slow wave cavity on one end face facing the feed port layer. One end of the serpentine slow wave cavity is provided with a feed signal terminal, which is connected to the feed port. Multiple waveguide radiation slots are provided at intervals in the serpentine channel of the serpentine slow wave cavity. Multiple radiating cavity units are spaced apart on one end face of the radiating slot layer facing the slow waveline layer. Each radiating cavity unit is arranged in a one-to-one correspondence with the waveguide radiating slot. Multiple radiating slots are spaced apart inside each radiating cavity unit. One end of each radiating cavity unit is provided with a signal connection terminal that is coupled to the waveguide radiating slot.

2. The waveguide slot antenna as described in claim 1, characterized in that, Each straight waveguide segment in the serpentine channel is provided with the waveguide radiation slot, and the serpentine channel is located below the feed signal end.

3. The waveguide slot antenna as described in claim 2, characterized in that, The centerline of the straight waveguide segment is offset from the centerline of its corresponding waveguide radiation slot, and the centerlines of the multiple waveguide radiation slots have different offsets.

4. The waveguide slot antenna as described in claim 3, characterized in that, The cross-section of the straight waveguide segment includes the wide side dimension a and the narrow side dimension b. The ratio e = d / a of the offset d of the centerline of the waveguide radiation slot to the wide side dimension a is 0 < e < 0.

5. The equivalent conductivity of the waveguide radiation slot increases as the ratio e increases.

5. The waveguide slot antenna as described in claim 4, characterized in that, The ratio c = b / a of the narrow side dimension b of the waveguide to the wide side dimension a of the waveguide is 0.2 ≤ c ≤ 0.

9.

6. The waveguide slot antenna as described in claim 4, characterized in that, The wide side dimension a of the waveguide is 1.37mm≤a≤4mm, the narrow side dimension b of the waveguide is 0.5mm≤b≤3.6mm, and the offset d of the centerline of the waveguide radiation slot is 0.005mm≤d≤1.8mm.

7. The waveguide slot antenna as described in claim 1, characterized in that, The radiation cavity unit has multiple radiation slots spaced upwards along the signal connection end, with adjacent radiation slots staggered on both sides of the vertical center line of the radiation cavity unit.

8. The waveguide slot antenna as described in any one of claims 1 to 7, characterized in that, A coupling layer is provided between the feed port layer and the slow wave line layer. The coupling layer has a coupling port corresponding to the feed port. The coupling port is connected to the feed port and the feed signal terminal respectively.

9. The waveguide slot antenna as described in claim 8, characterized in that, The other end of the serpentine slow wave cavity is provided with a signal discharge port, and both the power supply port layer and the coupling layer are provided with discharge ports corresponding to the signal discharge port.

10. The waveguide slot antenna as described in claim 9, characterized in that, The radiation cavity unit is provided with a first vent hole at the end away from the signal connection terminal, and the feed port layer, the slow wave line layer and the coupling layer are each provided with a second vent hole corresponding to the first vent hole.

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