Electric control beam scanning leaky-wave antenna and communication equipment

Abstract

The invention discloses an electrically-controlled beam scanning leaky-wave antenna and communication equipment, belongs to the technical field of antennas, and is used for solving the problems that an existing antenna is complex in structure and the beam scanning angle is limited under a fixed frequency. The electrically controlled beam scanning leaky-wave antenna comprises a gap waveguide and a plurality of radiation units. The gap waveguide comprises a cover plate and a metal bottom plate which are oppositely arranged, and a ridge structure arranged on the upper surface of the metal bottom plate in the transmission direction of the electromagnetic waves, and the gap waveguide is used for transmitting the electromagnetic waves in a traveling wave mode; the plurality of radiation units are sequentially arranged on the cover plate along the extension direction of the ridge structure; each radiation unit comprises a radiation patch, two radiation slots and two electric control switches which are sequentially arranged from top to bottom, and the radiation slots and the electric control switches are distributed in a central symmetry manner relative to the radiation patch; and each electric control switch is used for controlling the working state of the corresponding radiation slot so as to regulate and control the radiation phase of the radiation unit and realize beam scanning.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of antennas, and particularly relates to an electrically-controlled beam scanning leaky-wave antenna and a communication device. BACKGROUND

[0002] In a wireless communication system, an antenna as a core component directly affects the communication quality. With the development of communication technology, a scanning antenna has gradually evolved from a traditional mechanical scanning technology with slow response speed and low pointing accuracy to an intelligent electrically-controlled beam scanning technology. The electrically-controlled beam scanning antenna can realize rapid pointing and reconstruction of a beam, significantly improves the system performance, and shows important application value in the fields of 5G (5th Generation Mobile Communication Technology), military phased array radar, unmanned automobile driving technology, satellite communication, etc.

[0003] At present, the electrically-controlled beam scanning antenna is mostly based on a phased array technology. By controlling the phase of a radiation unit on an array surface, the antenna can realize beam scanning. In addition, a planar reflective / transmissive array antenna can also produce an expected radiation beam by reasonably designing the form and size of each radiation unit and adjusting the phase of an incident wave to form a specific phase distribution on the antenna aperture, thereby realizing electrically-controlled scanning of the beam.

[0004] However, in the phased array, a large number of phase shifters or radio frequency chips are usually needed to control the phase of the radiation unit, resulting in complex design of the feed network, and therefore the phased array antenna is expensive and has high system complexity. Especially in an active phased array, an independent receiving / transmitting component needs to be provided for each radiation unit, resulting in a large hardware scale and rapid increase of power consumption and cost. Although the planar reflective / transmissive array antenna has the advantages of low system complexity and low cost, the planar reflective / transmissive array antenna still needs a feed source to realize energy radiation. The planar reflective array antenna will cause poor beam performance in some areas due to the blockage of the feed source. The feed source in the planar transmissive array antenna will not block the antenna radiation, but still has the problem of high profile, which is not suitable for integrated systems, so that its application in a small communication system is limited. Moreover, the radiation unit of the planar reflective / transmissive array antenna is usually composed of multiple layers, and the design complexity is high.

[0005] To this end, the related art uses a leaky-wave structure to implement beam scanning. By designing the geometric parameters of the periodic structure of the leaky-wave antenna, the phase constant of the leaky-wave mode can be regulated to achieve beam scanning. The leaky-wave structure has the inherent property that the beam angle changes with the operating frequency, which limits the beam scanning angle to be usually changed with the frequency. With the development of communication technology, many system devices and mobile terminals operate in a specific frequency band range, and therefore the conventional leaky-wave antenna that changes the beam pointing with the frequency is not suitable for most communication systems due to the limited scanning range. Therefore, it is particularly necessary to provide a more optimal electrically-controlled beam scanning antenna. SUMMARY

[0006] Embodiments of the present application provide an electrically-controlled beam scanning leaky-wave antenna and a communication device, which can solve the problem that the existing antenna has a complex structure and the beam scanning angle is limited at a fixed frequency.

[0007] To solve the above technical problem, embodiments of the present application adopt the following technical solutions: The embodiments of the present application provide an electrically-controlled beam scanning leaky-wave antenna, which comprises a gap waveguide and a plurality of radiation units; wherein, The gap waveguide comprises a cover plate and a metal bottom plate arranged oppositely, and a ridge structure arranged on the upper surface of the metal bottom plate along the transmission direction of electromagnetic waves, and the gap waveguide is used to transmit electromagnetic waves in the form of a traveling wave; The plurality of radiation units are arranged on the cover plate in sequence along the extension direction of the ridge structure; each radiation unit comprises a radiation patch, a radiation slot and an electrically-controlled switch arranged in sequence from top to bottom, the number of the radiation slot and the electrically-controlled switch is both two, and both are centrally symmetrically distributed about the radiation patch; each electrically-controlled switch is used to control the working state of the corresponding radiation slot to regulate the radiation phase of the radiation unit and realize beam scanning; each radiation slot, when in the working state, leaks electromagnetic waves in the gap waveguide and couples to the radiation patch to excite radiation. In one embodiment, the ridge structure comprises a plurality of metal ridges, the plurality of metal ridges are periodically arranged on the upper surface of the metal bottom plate along the transmission direction of electromagnetic waves, and the plurality of metal ridges correspond one-to-one to the plurality of radiation units.

[0008] In one embodiment, the electrically-controlled switch comprises a first electrically-controlled switch and a second electrically-controlled switch, and the radiation slot comprises a first radiation slot and a second radiation slot; The first electrically-controlled switch and the second electrically-controlled switch are centrally symmetrically distributed with respect to the metal ridge, and the first radiation slot and the second radiation slot are centrally symmetrically distributed with respect to the metal ridge.

[0009] In an embodiment, the cover plate comprises, from top to bottom, a first dielectric layer, a metal layer and a second dielectric layer. The radiation patch is arranged on an upper surface of the first dielectric layer. The first radiation slot and the second radiation slot are formed in the metal layer. The first electrically-controlled switch and the second electrically-controlled switch are arranged on a lower surface of the second dielectric layer. The second dielectric layer has a gap with the metal ridge.

[0010] In an embodiment, each radiation unit further comprises a first metal patch, a second metal patch and a third metal patch arranged on the lower surface of the second dielectric layer, the first metal patch, the second metal patch and the third metal patch are equally spaced along the transmission direction of the electromagnetic wave, and the second metal patch is arranged opposite to the metal ridge. The first electrically-controlled switch is connected to the first metal patch and the second metal patch respectively, and the second electrically-controlled switch is connected to the second metal patch and the third metal patch respectively.

[0011] In an embodiment, each radiation unit further comprises a metal via arranged on the second dielectric layer, the metal via is used to electrically connect the second metal patch and the metal layer.

[0012] In an embodiment, the radiation slot is a T-shaped longitudinal slot, an H-shaped longitudinal slot or a rectangular longitudinal slot.

[0013] In an embodiment, the electrically-controlled switch is one of a PIN diode, a capacitor, an inductor and a micro motor switch.

[0014] In an embodiment, the radiation patch is a square corner-cut patch or a circular patch.

[0015] The embodiments of the present application also provide a communication device comprising the electrically-controlled beam scanning leaky-wave antenna.

[0016] The above at least one technical scheme adopted by the embodiments of the present application can achieve the following beneficial effects: The electrically-controlled beam scanning leaky-wave antenna provided by the embodiments of the present application comprises a gap waveguide and a plurality of radiation units. The gap waveguide comprises a cover plate and a metal bottom plate arranged oppositely, and a ridge structure arranged on the upper surface of the metal bottom plate along the transmission direction of electromagnetic waves, and is used for transmitting electromagnetic waves in the form of a traveling wave. In the technical solution, the gap waveguide is used as a basic traveling wave transmission structure, and in order to avoid fast wave radiation, a row of ridge structures is designed along the transmission direction of the gap waveguide. In this way, by selecting a suitable ridge height, the gap waveguide can exhibit suitable slow wave transmission characteristics, thereby avoiding the fixed radiation of fast waves. Moreover, the plurality of radiation units are arranged on the cover plate along the extension direction of the ridge structure in sequence, each radiation unit comprises a radiation patch, a radiation slot and an electrically-controlled switch arranged in sequence from top to bottom, and the number of the radiation slot and the electrically-controlled switch is both two and they are both centrally symmetrically distributed about the radiation patch. Each radiation slot leaks electromagnetic waves in the gap waveguide and couples to the radiation patch to excite radiation when in the working state. Each electrically-controlled switch is used for controlling the working state of the corresponding radiation slot to regulate the radiation phase of the radiation unit, so as to construct a quasi-uniform phase distribution on the antenna aperture surface based on the different phase compensation provided by the radiation units, so as to realize electrically-controlled beam scanning, which is conducive to realizing wide-angle beam scanning at a fixed frequency and is suitable for a communication system that needs wide-angle coverage and narrow band. It can be seen that the technical solution realizes electrically-controlled beam scanning by loading an electrically-controlled switch instead of using a plurality of phase shifters and a complex feed network, which not only simplifies the structure of the antenna and reduces the design complexity of the antenna, but also greatly reduces the power consumption and cost of the antenna, adapts to the requirement of modern communication systems for low cost, and the leaky-wave structure has the characteristics of low profile and easy integration. The above arrangement makes the radiation beam of the antenna provided by the present application have the characteristics of wide-angle coverage, high gain and electrically-controlled scanning, and the leaky-wave structure itself has the advantages of low profile, easy processing and easy integration, so that the electrically-controlled beam scanning leaky-wave antenna provided by the embodiments of the present application has the advantages of high gain, high efficiency, low profile and light weight, and is suitable for most communication systems. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 FIG. 1 is a structural schematic diagram of an electrically-controlled beam scanning leaky-wave antenna provided by an embodiment of the present application; Figure 2 FIG. 2 is a structural schematic diagram of a radiation unit provided by an embodiment of the present application; Figure 3 FIG. 3 is a structural schematic diagram of an electrically-controlled beam scanning leaky-wave antenna provided by another embodiment of the present application; Figure 4 FIG. 4 is a structural schematic diagram of an electrically-controlled beam scanning leaky-wave antenna provided by another embodiment of the present application; Figure 5 FIG. 5 is a radiation characteristic diagram of a radiation unit provided by an embodiment of the present application; Figure 6 is a schematic diagram of a beam scanning principle provided by an embodiment of the present application; Figure 7 is a normalized radiation pattern of an electronically-controlled beam scanning leaky-wave antenna provided by an embodiment of the present application; Figure 8 is a schematic diagram of an S parameter of an electronically-controlled beam scanning leaky-wave antenna provided by an embodiment of the present application; Figure 9 is a schematic diagram of gain and axial ratio of an electronically-controlled beam scanning leaky-wave antenna provided by an embodiment of the present application; Figure 10 is a schematic diagram of a structure of a communication device provided by an embodiment of the present application.

[0018] In the drawings, various reference numerals are used throughout the drawings. 1-gap waveguide; 11-cover plate; 111-first dielectric layer; 112-metal layer; 113-second dielectric layer; 12-metal bottom plate; 13-ridge structure; 131-metal ridge; 14-metal pin; 2-radiating unit; 21-radiating patch; 221-first radiating slot; 222-second radiating slot; 231-first electrically-controlled switch; 232-second electrically-controlled switch; 24-first metal patch; 25-second metal patch; 26-third metal patch; 27-metal via hole; 3-antenna feed; 4-matching load; 5-beam control module; 1000-communication device; 1010-electronically-controlled beam scanning leaky-wave antenna. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0020] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of a kind and are not limited in number, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / ", generally indicates that the objects before and after are in an "or" relationship.

[0021] Figure 1 is a structural schematic diagram of an electrically-controlled beam scanning leaky-wave antenna provided by an embodiment of the present application, Figure 2 is a structural schematic diagram of a radiation unit. As shown in Figures 1-2 , the electrically-controlled beam scanning leaky-wave antenna includes a gap waveguide 1 and a plurality of radiation units 2.

[0022] The gap waveguide 1 includes oppositely arranged cover plates 11 and a metal bottom plate 12, and a ridge structure 13 arranged on the upper surface of the metal bottom plate 12 along the transmission direction of electromagnetic waves. The gap waveguide is used to transmit electromagnetic waves in the form of a traveling wave.

[0023] The plurality of radiation units 2 are arranged in sequence on the cover plates 11 along the extension direction of the ridge structure 13. Each radiation unit 2 includes, arranged in sequence from top to bottom, a radiation patch 21, a radiation slot, and an electrically-controlled switch. The number of the radiation slot and the electrically-controlled switch is both two, and both are centrally symmetrically distributed about the radiation patch 21. Each electrically-controlled switch is used to control the working state of the corresponding radiation slot, to regulate the radiation phase of the radiation unit, to realize beam scanning. Each radiation slot, in the case of being in a working state, leaks electromagnetic waves in the gap waveguide, and couples to the radiation patch to excite radiation.

[0024] Among them, in order to avoid fast wave radiation, a row of slow wave ridges is designed along the transmission direction of the gap waveguide in this technical solution, so that by selecting a suitable slow wave ridge height, the gap waveguide can exhibit slow wave transmission characteristics above 27GHz (gigahertz). In addition, the height of the slow wave ridge can be designed to gradually change at both ends, to realize better impedance matching with the antenna feed and the matching load.

[0025] According to the polarization mode of the antenna, it can be divided into linearly polarized antenna and circularly polarized antenna. Among them, the circularly polarized antenna can receive electromagnetic waves of any polarization to avoid polarization loss, and can also suppress multipath effect, has higher adaptability and anti-interference degree, and is more practical in radar system, satellite system and electronic jamming system and other scenes. Based on this, in the electrically controlled beam scanning leaky-wave antenna provided by the embodiments of the present application, the radiating patch can be designed as a square cut corner patch or a circular patch to realize a circularly polarized antenna.

[0026] Optionally, the material of the cover plate is Rogers RT5880. The radiation slot can be a T-shaped longitudinal slot, an H-shaped longitudinal slot or a rectangular longitudinal slot. The electrically controlled switch can be one of a PIN diode, a capacitor, an inductor, and a micro motor switch. The number of radiation units can be 32, and they are arranged on the cover plate along the extension direction of the ridge structure with a period of 3.2 mm (millimeters). Among them, in the case of using a T-shaped longitudinal slot or an H-shaped longitudinal slot, the radiation effect of the antenna is better than that of the antenna using a rectangular longitudinal slot.

[0027] It should be pointed out that the drawings in the present application are only used for illustration and not for limitation. For example, the shape of the radiating patch is not limited to square cut corner, but can also be circular; the number of radiating patches is not limited to the number shown in the figure, and can be designed according to the specific application scene; the radiation slot is not limited to T-shaped longitudinal slot, but can also be H-shaped longitudinal slot or rectangular longitudinal slot.

[0028] The electrically-controlled beam scanning leaky-wave antenna provided by the embodiments of the present application comprises a gap waveguide and a plurality of radiating units. The gap waveguide comprises oppositely arranged cover plates and a metal bottom plate, and a ridge structure arranged on the upper surface of the metal bottom plate along the transmission direction of electromagnetic waves, and the gap waveguide is used to transmit electromagnetic waves in the form of a traveling wave. In the technical solution, the gap waveguide is used as a basic traveling wave transmission structure, and in order to avoid fast wave radiation, a row of ridge structures is designed along the transmission direction of the gap waveguide. In this way, by selecting a suitable ridge height, the gap waveguide can exhibit suitable slow wave transmission characteristics, thereby avoiding the fixed radiation of fast waves. Moreover, the plurality of radiating units are arranged on the cover plate along the extension direction of the ridge structure in sequence, each radiating unit comprises, from top to bottom, a radiating patch, a radiating slot and an electrically-controlled switch, and the number of the radiating slot and the electrically-controlled switch is both two and they are both centrally symmetrically distributed about the radiating patch. Each radiating slot, in the case of being in a working state, leaks electromagnetic waves in the gap waveguide and couples to the radiating patch to excite radiation. Each electrically-controlled switch is used to control the working state of the corresponding radiating slot to regulate the radiation phase of the radiating unit, so as to construct a quasi-uniform phase distribution on the antenna aperture surface based on the different phase compensation provided by the radiating units, so as to realize electrically-controlled beam scanning, which is conducive to realizing wide-angle beam scanning at a fixed frequency and is suitable for a communication system that needs wide-angle coverage in a narrow band. It can be seen that the technical solution realizes electrically-controlled beam scanning by loading an electrically-controlled switch instead of using a plurality of phase shifters and a complex feed network, which not only simplifies the structure of the antenna and reduces the design complexity of the antenna, but also greatly reduces the power consumption and cost of the antenna, adapts to the requirement of modern communication systems for low cost, and the leaky-wave structure has a low profile and is easy to integrate into a system. The above arrangement makes the antenna provided by the present application have the characteristics of wide-angle coverage, high gain and electrically-controlled scanning, and the leaky-wave structure itself has the advantages of low profile, easy processing and easy integration, so that the electrically-controlled beam scanning leaky-wave antenna provided by the embodiments of the present application has the advantages of high gain, high efficiency, low profile and light weight, and is suitable for most communication systems.

[0029] In one embodiment, as shown in Figure 1 The ridge structure 13 comprises a plurality of metal ridges 131 arranged on the upper surface of the metal bottom plate 12 along the transmission direction of electromagnetic waves, and the plurality of metal ridges 131 correspond to the plurality of radiating units 2 one by one. Figures 1-2 The corresponding relationship between the metal ridges and the radiating units can be seen from

[0030] The one-to-one correspondence between the plurality of metal ridges and the plurality of radiation units means that the number of metal ridges is consistent with the number of radiation units, and the spatial position relationship is directly opposite, that is, one metal ridge corresponds to one radiation unit, and the center of the metal ridge and the center of the corresponding radiation unit are located on one vertical line. Optionally, the metal ridge can be a column structure, and the column structure can be circular, rectangular, elliptical, square, or the like in a cross section parallel to the plane of the metal bottom plate.

[0031] In one embodiment, as shown in FIG. 1, the electronically controlled beam scanning leaky-wave antenna can include an antenna feed 3 and a matching load 4, both of which are connected with the gap waveguide 1. The antenna feed 3 is used to feed electromagnetic waves into the gap waveguide 1, and the matching load 4 is used to absorb the remaining electromagnetic waves. Figure 3

[0032] If the transmission direction of the electromagnetic wave is along the positive x-axis, then in the antenna structure shown in FIG. 2, the antenna feed is connected with the left end of the antenna structure, and the matching load is connected with the right end of the antenna structure. It can be understood that in actual application, both the left and right ends of the antenna structure are designed with connection ports, and the antenna feed and the matching load are respectively connected with the corresponding connection ports. Optionally, to achieve better impedance matching with the antenna feed and the matching load, the height of the metal ridge can be gradually changed (e.g., reduced) at both ends of the gap waveguide. Figure 1

[0033] In one embodiment, as shown in FIG. 3, the gap waveguide 1 can include a plurality of metal pins 14, which are periodically arranged on both sides of the ridge structure 13. Optionally, the metal pin can be a column structure, and the column structure can be circular, rectangular, elliptical, square, or the like in a cross section parallel to the plane of the metal bottom plate. Figure 1 In this embodiment, the metal pins periodically arranged on both sides of the ridge structure form an EBG (Electromagnetic Band Gap) structure, which has a band gap characteristic and can prevent electromagnetic waves from propagating in a non-ridge direction, thereby avoiding electromagnetic wave leakage problems. As shown in FIG. 4, the top end of the metal pin can be in contact with the lower surface of the second dielectric layer 113, which makes the height of the metal pin higher than the height of the metal ridge. In this way, not only can the air gap be formed between the metal ridge and the cover plate, but also the electromagnetic wave can be better confined inside the waveguide.

[0034] Figures 1-2 In one embodiment, as shown in FIG. 5, the electronically controlled switch includes a first electronically controlled switch 231 and a second electronically controlled switch 232, and the radiation slot includes a first radiation slot 221 and a second radiation slot 222.

[0035] Figures 1-2

[0036] ​​​​​In each set of corresponding metal ridges and radiating units, the first and second electronically controlled switches are centrally symmetrically distributed about the metal ridge, as are the first and second radiating slots. The radiating patch is positioned opposite to the metal ridge. In application, the spatial relationship between the radiating patch and the metal ridge can be directly opposite each other.

[0037] In one embodiment, such as Figures 1-2 As shown, the cover plate 11 includes, from top to bottom, a first dielectric layer 111, a metal layer 112, and a second dielectric layer 113.

[0038] The radiating patch 21 is disposed on the upper surface of the first dielectric layer 111, the first radiating slot 221 and the second radiating slot 222 are formed on the metal layer 112, and the first electronic switch 231 and the second electronic switch 232 are disposed on the lower surface of the second dielectric layer 113. There is a gap between the second dielectric layer and the metal ridge.

[0039] Optionally, the thickness of the first dielectric layer can be 0.508 mm, and the thickness of the second dielectric layer can be 0.762 mm.

[0040] In one embodiment, such as Figure 2 As shown, each radiating unit 2 may include a first metal patch 24, a second metal patch 25, and a third metal patch 26 disposed on the lower surface of the second dielectric layer 113. The first metal patch 24, the second metal patch 25, and the third metal patch 26 are equally spaced along the direction of electromagnetic wave propagation, and the second metal patch is disposed opposite to the metal ridge. In application, the spatial relationship between the second metal patch and the metal ridge can be directly opposite each other.

[0041] The first electronic switch 231 is connected to the first metal patch 24 and the second metal patch 25, respectively, and the second electronic switch 232 is connected to the second metal patch 25 and the third metal patch 26, respectively. Optionally, the first metal patch, the second metal patch, and the third metal patch can be metal pads.

[0042] In one embodiment, such as Figure 2 As shown, each radiation unit 2 may include a metal via 27 disposed in the second dielectric layer 113, the metal via 27 being used for electrically connecting the second metal patch 25 and the metal layer 112. Figure 2 The diagram schematically shows four metal through-holes, while Figure 4 Only one metal through hole is shown schematically. It is understood that in application, the number of metal through holes can be designed according to the needs of specific application scenarios, and this application embodiment does not limit this.

[0043] In the application, the metal layer can be grounded, so that the second metal patch of each radiation unit is grounded through the metal via by one bias line, without the bias line between each second metal patch and the ground, avoiding the use of a large number of bias lines and reducing the wiring design complexity.

[0044] In one embodiment, as shown in FIG. 1, the electronically-controlled beam scanning leaky-wave antenna can include a beam control module 5. The beam control module 5 is connected with the first metal patch 24, the third metal patch 26 and the metal layer 112 respectively, for outputting a control voltage to the electrically-controlled switch to realize the phase control of the radiation unit and the beam scanning of the antenna. Figure 4

[0045] In the control circuit of the first electrically-controlled switch, the positive pole of the beam control module is connected with the first metal patch, the first metal patch, the first electrically-controlled switch, the second metal patch, the metal via and the metal layer are connected in sequence, and the metal layer is connected with the negative pole of the beam control module. In the control circuit of the second electrically-controlled switch, the positive pole of the beam control module is connected with the third metal patch, the third metal patch, the second electrically-controlled switch, the second metal patch, the metal via and the metal layer are connected in sequence, and the metal layer is connected with the negative pole of the beam control module.

[0046] The above is the electronically-controlled beam scanning leaky-wave antenna provided by the embodiments of the present application. Next, the beam scanning principle of the electronically-controlled beam scanning leaky-wave antenna will be described in detail with the antenna structure shown in FIG. 1 as an example. In this embodiment, 32 radiation units are arranged on the cover plate along the extension direction of the ridge structure with a period of 3.2 mm, and PIN diodes are used as the electrically-controlled switches. The first electrically-controlled switch is a first PIN diode, and the second electrically-controlled switch is a second PIN diode. In actual application, the feasibility and applicability of the antenna can be verified by modeling simulation, and the related simulation results can be referred to Figures 1-4 Figure 5 Figures 7-9 .

[0047] In this embodiment, a circularly polarized electronically-controlled beam scanning leaky-wave antenna based on phase control is realized. The antenna uses a traveling wave waveguide to feed and realizes the dynamic regulation and control of the beam by loading PIN diodes, which avoids the complex feed network and beam forming algorithm compared with phased array, and does not need to use transmitting / receiving components, so that the cost and power consumption of the antenna are greatly reduced. By waveguide feeding, no additional feed source is needed to provide incident wave irradiation. The antenna profile proposed in this embodiment is only 4.3 mm, which has the characteristics of low profile and is easy to integrate into a system. Moreover, by using PIN diodes to regulate the phase compensation value of the radiation unit, an equivalent phase constant capable of radiating a beam is constructed on the antenna aperture, and then the electronically-controlled scanning of the beam is realized by changing the equivalent phase constant of the aperture field, which is different from the existing fixed frequency beam scanning leaky-wave antenna. ​​​

[0048] Specifically, each radiation slot is controlled by an independent PIN diode. The bias state of the PIN diode can be controlled by the beam control module, so as to control the corresponding radiation slot to be opened or closed, so as to change the radiation state of the radiation unit. When the PIN diode is forward biased, the radiation slot presents a short-circuit state, which realizes the effect of closing the radiation slot in the working frequency band, at this time the radiation patch is hardly excited by energy. When the PIN diode is not biased, the radiation slot presents an open-circuit state, which can realize the coupling of the energy in the gap waveguide to the radiation patch, so that the radiation unit can effectively radiate.

[0049] The base film in the embodiment is TE 10 , according to the symmetry of the TE 10 mode, when the two PIN diodes are forward biased respectively, the radiation unit will generate two radiation fields with opposite phases but the same amplitude, thereby realizing 1bit phase control of the radiation unit. If the numbers "1" and "-1" are used as the encoding of the two radiation states, then the correspondence between the radiation state and the PIN diode bias state can be as shown in Table 1.

[0050] Table 1

[0051] As Figure 5 shown, the simulation results of the radiation power and the far-field phase of the radiation unit are shown, which can prove the feasibility of using PIN diodes to control the phase of the radiation unit. From Figure 5 it can be seen that the radiation unit can work in two radiation states, the radiation power intensity is the same and the phase difference is 180°, that is, the radiation unit can realize 1bit phase perturbation.

[0052] Based on this, the beam scanning principle is analyzed in detail as follows: when the fundamental mode in the traveling wave structure is a slow wave, electromagnetic energy mainly exists in the form of surface waves at the antenna aperture, and spatial harmonics can be excited under the action of periodic modulation. Unlike the existing periodic amplitude modulation leaky-wave antenna, the beam scanning is realized by controlling the phase distribution along the aperture of the leaky-wave antenna through electrically controlled switches. As Figure 6 shown, the original phase constant in the waveguide is denoted as , if an appropriate phase perturbation value is provided along each radiation unit of the leaky-wave antenna on the fundamental mode with , a new equivalent phase constant can be constructed, and it can be regarded as the phase constant of the quasi-continuous aperture field. Therefore, if the value of the equivalent phase constant is between (-1, 1), the radiation of the beam can be realized, , ​is the wave number in free space. By constructing different equivalent phase constants , the beam scanning of the antenna can be realized.

[0053] In order to construct different equivalent phase constants in the actual antenna, each radiating element on the aperture of the antenna should provide a specific phase compensation. The phase difference between adjacent radiating elements is caused by the base wave , is the pitch of adjacent radiating elements. Assuming that the target beam angle is , the equivalent phase constant of the aperture field can be calculated by the following formula (1).

[0054] (1) Let the phase compensation value of any nth radiating element be . As shown in formula (2), by calculating the difference between the ideal phase distribution on the aperture of the antenna and the phase distribution in the leaky-wave structure, the phase compensation value of each radiating element can be obtained. .

[0055]

[0056] (2) In formula (2), the wave number in free space is selected as 565 rad / m (radian / meter) corresponding to the frequency of 27 GHz. The original phase constant is determined by the transmission structure, and the specific value can be obtained by eigenmode simulation. In this embodiment, the value is about 600 rad / m. The period is known when the antenna structure is determined, and in this embodiment, it is 3.2 mm. It can be understood that in the design of the antenna, by controlling the height, width and gap waveguide width of the ridge structure, the size of the original phase constant inside the gap waveguide can be reasonably changed.

[0057] Therefore, the phase compensation value that each radiating element in the antenna should provide at any target beam pointing direction can be calculated by formula (2). And by changing the phase compensation provided by each radiating element, different beam pointing directions can be obtained.

[0058] However, it should be noted that the phase compensation calculated by formula (2) for each radiating element is an ideal value, while each radiating element in this embodiment can only provide discrete phase compensation values ​​(i.e., 0° and 180°). Therefore, the antenna aperture field exhibits a quasi-uniform phase distribution. Based on this, the phase compensation value calculated by formula (2) needs to be quantized, resulting in: If 90°≤ <270°, then Quantized to 180°, it is represented as radiation state -1; If 0°≤ <90° or 270°≤ <360°, then The quantization is 0°, which is represented as radiation state 1.

[0059] Based on the beam scanning principle and the phase compensation value calculation and quantization method provided above, the radiation state encoding sequence of the radiating element corresponding to any beam angle can be obtained. Table 2 shows the encoding sequences corresponding to different beam angles selected at 10° intervals, covering the range from 50° backward to 60° forward.

[0060] Table 2

[0061] by The third (i.e., n=) at 30° Taking the radiation state of a radiation element as an example, this section details how the radiation state of each radiation element is determined in practical applications. It can be determined through calculation. ,because and The units are all radians per meter, therefore the calculated... The value is in radians, and in applications it needs to be converted to angles, i.e., using... Since -116.5° does not fall within the 0 to 360° range, it can be quantized by adding 360° to it. Referring to the quantification method described above, it can be seen that 243.5° falls within the range of 90° to 270°, therefore it can be... The quantization is 180°, and the radiation state of this radiation element is -1.

[0062] Using the radiation state encoding sequences of the radiating elements corresponding to different beam angles in Table 2 above, a full-wave simulation analysis was performed on the antenna to obtain the normalized radiation pattern at 27 GHz. Figure 7 As shown. From Figure 7As can be observed, the antenna's beam pointing changes from -50° to 60°, achieving a beam coverage range of 110°. This means it achieves a large-angle beam scan of 110° at a fixed frequency of 27 GHz, making the antenna suitable for narrowband communication systems requiring wide-angle coverage. This result also verifies that the method proposed in this application for constructing an equivalent phase constant based on radiating element phase control can effectively achieve beam scanning.

[0063] The full-wave simulation results of the S-parameters are as follows: Figure 8 As shown. For ease of observation, three representative beam angles were selected for analysis: -50° (backward), 0° (end-fire), and +60° (forward). It can be seen that in the range of 25 GHz to 30 GHz, the reflection coefficient S... 11 Almost all values ​​were less than -10 dB, indicating good impedance matching characteristics of the antenna. At 27 GHz, the transmission coefficient S... 21 A reading below -10dB indicates that there is almost no remaining power at the antenna tip.

[0064] exist Figure 9 The full-wave simulation results of the antenna's gain and axial ratio are presented in the figure. The peak gain of the antenna is 13.4 dBic (the unit of gain for a circularly polarized antenna), and the gain results show slight fluctuations as the antenna beam is scanned. Furthermore, the axial ratio is less than 3 dB at most angles, verifying the excellent circular polarization characteristics of the antenna's radiation field. The above simulation data indicate that the leaky-wave antenna proposed in this application has potential applicability in satellite communication systems.

[0065] In this embodiment, the leaky-wave antenna itself features low profile (suitable for integration into mobile platforms) and low cost, while the electronic control design further enhances the dynamic beam control capability, surpassing traditional designs. This allows it to meet the demands of 5G for high-frequency, high-capacity communication, with significant potential, especially in dynamic scenarios and high-reliability communications. With the increasing penetration rate of 5G base stations and the development of satellite internet, circularly polarized electronically controlled beam-scanning leaky-wave antennas demonstrate broad development potential in the mobile communication field, and are expected to provide strong technical support for emerging application scenarios such as vehicle-to-everything (V2X) and smart cities.

[0066] Based on the electrically controlled beam scanning leaky antenna provided in the above embodiments, this application also provides a communication device 1000, which includes the electrically controlled beam scanning leaky antenna 1010 provided in the above embodiments.

[0067] Among them, communication equipment includes, but is not limited to, base stations, radar, mobile phones, tablets, e-readers, smart wearable devices, routers, remote controls, Internet of Things devices, and any communication equipment that uses antenna structures to transmit energy or electromagnetic waves.

[0068] It can be understood that the communication device has all the technical effects of the electrically controlled beam scanning leaky-wave antenna, which will not be described here.

[0069] The embodiments of the present application are described above with reference to the accompanying drawings, but the present application is not limited to the specific embodiments described above, which are only illustrative but not restrictive. Those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, which all belong to the protection of the present application.

Claims

1. An electrically controlled beam scanning leaky-wave antenna, characterized by, The antenna comprises a gap waveguide and a plurality of radiation units; wherein The gap waveguide comprises a cover plate and a metal bottom plate arranged oppositely, and a ridge structure arranged on the upper surface of the metal bottom plate along the transmission direction of electromagnetic waves, and is used for transmitting electromagnetic waves in the form of a traveling wave. The plurality of radiation units are arranged on the cover plate along the extension direction of the ridge structure in sequence; each radiation unit comprises a radiation patch, a radiation slot and an electrically controlled switch arranged in sequence from top to bottom, the number of the radiation slot and the electrically controlled switch is both two, and they are both centrally symmetrically distributed about the radiation patch; each electrically controlled switch is used for controlling the working state of the corresponding radiation slot to regulate the radiation phase of the radiation unit, so as to realize beam scanning; and each radiation slot leaks electromagnetic waves in the gap waveguide and couples to the radiation patch to excite radiation when in the working state.

2. The electronically controlled beam scanning leaky-wave antenna according to claim 1, wherein, The ridge structure comprises a plurality of metal ridges, which are periodically arranged on the upper surface of the metal bottom plate along the transmission direction of electromagnetic waves, and the plurality of metal ridges correspond to the plurality of radiation units one by one.

3. The electronically controlled beam scanning leaky-wave antenna according to claim 2, wherein, The electrically controlled switch comprises a first electrically controlled switch and a second electrically controlled switch, and the radiation slot comprises a first radiation slot and a second radiation slot; In each group of corresponding metal ridges and radiation units, the first electrically controlled switch and the second electrically controlled switch are centrally symmetrically distributed about the metal ridge, the first radiation slot and the second radiation slot are centrally symmetrically distributed about the metal ridge, and the radiation patch is arranged opposite to the metal ridge.

4. The electronically controlled beam scanning leaky-wave antenna according to claim 3, wherein, The cover plate comprises a first dielectric layer, a metal layer and a second dielectric layer in sequence from top to bottom; The radiation patch is arranged on the upper surface of the first dielectric layer; The first radiation slot and the second radiation slot are formed in the metal layer; The first electrically controlled switch and the second electrically controlled switch are arranged on the lower surface of the second dielectric layer; The second dielectric layer has a gap with the metal ridge.

5. The electronically controlled beam scanning leaky-wave antenna according to claim 4, wherein, Each radiation unit further comprises a first metal patch, a second metal patch and a third metal patch arranged on the lower surface of the second dielectric layer, the first metal patch, the second metal patch and the third metal patch are equally spaced along the transmission direction of electromagnetic waves, and the second metal patch is arranged opposite to the metal ridge; The first electrically controlled switch is connected with the first metal patch and the second metal patch respectively, and the second electrically controlled switch is connected with the second metal patch and the third metal patch respectively.

6. The electronically controlled beam scanning leaky-wave antenna according to claim 5, wherein, Each radiation unit further comprises a metal via hole arranged in the second dielectric layer, which is used for electrically connecting the second metal patch and the metal layer.

7. The electronically controlled beam scanning leaky-wave antenna according to claim 1, wherein, The radiation slot is a T-shaped longitudinal slot, an H-shaped longitudinal slot or a rectangular longitudinal slot.

8. The electronically controlled beam scanning leaky-wave antenna according to claim 1, wherein, The electrically controlled switch is one of a PIN diode, a capacitor, an inductor and a micro motor switch.

9. The electronically controlled beam scanning leaky-wave antenna according to claim 1, wherein, The radiation patch is a square corner-cut patch or a circular patch.

10. A communication device, characterized by The antenna comprises the electrically controlled beam scanning leaky wave antenna according to any one of claims 1-9.

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