CN113745833B - Waveguide antenna and signal transmission device - Google Patents

Abstract

The present application discloses a waveguide antenna and a signal transmission device, the waveguide antenna comprising: a first substrate, comprising a waveguide port located on a first surface; a second substrate, located on the first substrate, the stacked structure formed by the second substrate and the first substrate having a transmission waveguide, one end of the transmission waveguide being connected to the waveguide port; at least one intermediate substrate, stacked and arranged on the second surface of the second substrate, forming a signal transmission path, having an input port and a plurality of output ports, and a plurality of power dividers connecting the input port and the output port, for connecting the input port to each output port; an antenna substrate, the antenna substrate being provided with a plurality of openings, the openings being used as waveguide antenna array elements. The above waveguide antenna is easy to install, can reduce the weight and cost of the waveguide antenna while ensuring the signal pass rate, and can be widely used in engineering sites.

Description

Waveguide antenna and signal transmission device

Technical Field

The present application relates to the field of signal technology, and in particular to a waveguide antenna and a signal transmission device.

Background technique

A waveguide is a pipe that can limit and guide the propagation of electromagnetic waves in the length direction. Waveguide antenna is a classic antenna form. It is a compact antenna that realizes the integration of waveguide transformation, transmission and radiation in a strongly constrained boundary. It has the characteristics of high efficiency, high power capacity and high structural strength. With the stringent requirements of highly integrated phased array antennas on efficiency, force and heat, the rapid increase in demand for millimeter wave antennas has made waveguide antennas one of the most active antenna forms in the current antenna field. The aperture distribution of waveguide array antennas is easier to control than other antennas, so it is easy to achieve low sidelobe performance, which makes it stand out among various radar antennas. Therefore, it has an irreplaceable position in the design of radars, communication antennas, etc. The high efficiency, low profile and lightweight of waveguide antennas are basic cutting-edge technologies to break through the bottleneck of electronic information equipment and enable future electronic information systems.

In microstrip electronic devices, in order to control the conduction path of microwave control signals, waveguides formed by microstrip lines on printed circuit boards (PCBs) or waveguides formed by metal cavities are usually used. By controlling and changing the shape of the microstrip lines or the shape of the metal cavities, functions such as filtering, power splitting and combining, coupling, and radiation of microwave signals can be achieved.

The traditional waveguide formed by the microstrip line of the printed circuit board (PCB) has a large signal loss for the frequency band above 60GHz, and due to the high dielectric constant of the PCB medium, the impedance characteristics of the microstrip line are greatly affected by the size, which requires high processing accuracy of the PCB, which greatly increases the cost and reduces the pass rate; the traditional waveguide formed by the metal cavity has a processing accuracy tolerance of micrometer level for the frequency band above 60GHz, and the shape is a three-dimensional shape, which requires the use of extremely high-precision molds and processing technology, which also leads to a significant increase in cost. In particular, the increase in its weight makes engineering application more difficult.

Therefore, how to reduce the weight of the waveguide antenna and lower the production cost is an urgent problem to be solved.

Summary of the invention

In view of this, the present application provides a waveguide antenna and a signal transmission device to solve the problems of heavy weight and high cost of existing waveguide antennas.

A waveguide antenna provided in the present application includes: a first substrate, having a first surface and a second surface relative to each other, including a waveguide port located on the first surface; a second substrate, located on the first substrate, having a first surface and a second surface relative to each other, the first surface of the second substrate being bonded to the second surface of the first substrate, a stacking structure formed by the second substrate and the first substrate having a transmission waveguide therein, one end of the transmission waveguide being connected to the waveguide port; at least one intermediate substrate, stacked and arranged on the second surface of the second substrate, a signal transmission path being formed in the stacking structure formed by the at least one intermediate substrate, the signal transmission path having an input port and a plurality of output ports, and a plurality of power dividers connecting the input port and the output ports, for connecting the input port to each output port; an antenna substrate, located on the at least one intermediate substrate, a plurality of openings being arranged in the antenna substrate, the openings serving as waveguide antenna array elements being connected to each output port.

Optionally, the first substrate, the second substrate, the intermediate substrate and the antenna substrate all include an insulating layer and a metal film covering at least a portion of the surface of the insulating layer; the metal film is formed on the inner wall surfaces of the waveguide port, the transmission waveguide and the signal transmission path.

Optionally, the thickness of the metal film is 1/200 of the wavelength of the center frequency of the working frequency band.

Optionally, the material of the metal film includes at least one of gold, silver, copper, aluminum and tin.

Optionally, the electrical conductivity of the metal film is greater than 10 s/cm.

Optionally, the material of the insulating layer includes at least one of polyphenylene sulfide, phenolic plastic, polyurethane plastic, epoxy plastic and unsaturated polyester plastic.

Optionally, the first substrate includes a waveguide port and a first transmission slot, and the waveguide port is connected to the first transmission slot; the second substrate includes a second transmission slot located on one side of the first surface of the second substrate, the second transmission slot is connected to the first transmission slot, and the opening edges are aligned to form the transmission waveguide.

Optionally, the second substrate further includes: a third transmission groove located on one side of the second surface of the second substrate, and a first transmission through hole located between the second transmission groove and the third transmission groove and connecting the second transmission groove and the third transmission groove.

Optionally, it includes an intermediate substrate, which includes a first surface and a second surface relative to each other; the first surface side of the intermediate substrate has a fourth transmission slot, and a fifth transmission slot is formed on the second surface side of the intermediate substrate, and the fourth transmission slot is connected to the fifth transmission slot through a second transmission hole; the third transmission slot of the second substrate and the fourth transmission slot of the intermediate substrate constitute a first power divider, which is used to distribute the signal received by the third transmission slot to each fifth transmission slot.

Optionally, the antenna substrate includes a first surface and a second surface relative to each other, the opening of the antenna substrate is located on the second surface side of the antenna substrate, and the antenna substrate also includes a plurality of sixth transmission slots located on the first surface side of the antenna substrate, each sixth transmission slot is connected to at least two of the openings; the fifth transmission slot of the intermediate substrate is connected to the sixth transmission slot of the antenna substrate, forming at least a second power divider and a third power divider for distributing the signal received by the fifth transmission slot to each of the openings.

Optionally, the cross-section of the transmission waveguide and the signal transmission path perpendicular to the signal transmission direction is rectangular.

Optionally, the length a and width b of the cross section satisfy: a=0.7λ, b=(0.4-0.5)λ, wherein a is the side length parallel to the first surface of each substrate, and b is the side length perpendicular to the first surface of each substrate.

Optionally, the waveguide length _GL of the transmission waveguide is _GL =P* _λg /360.00, wherein _λg is the waveguide wavelength of the transmission waveguide, and P is the phase of the transmission signal.

Furthermore, the waveguide wavelength λ _g of the waveguide antenna is Wherein, _λg is the waveguide wavelength, _λ0 is the working center frequency wavelength, and _εr is the dielectric constant of the dielectric layer of the waveguide antenna.

Optionally, at least one side wall of the fifth transmission slot of the second power divider and the third power divider is a stepped structure.

A waveguide antenna provided in the present application further includes: a positioning pin and a positioning hole, wherein the positioning pin and the positioning hole are respectively located on two sides of the adjacent substrates that are bonded together, and the positioning pin is embedded in the positioning hole.

The present application also provides a signal transmission device, comprising: a waveguide antenna as described in any one of the above items; a signal converter, the signal converter is connected to the waveguide port, and the signal converter is used to generate electromagnetic waves and transmit them to the waveguide antenna.

The waveguide antenna of the present invention comprises a first substrate, a second substrate, at least one intermediate substrate and an antenna substrate. The first surface of the second substrate is connected to the second surface of the first substrate. The at least one intermediate substrate is stacked and arranged on the second surface of the second substrate. The antenna substrate is located on the at least one intermediate substrate. The substrate theme of the waveguide antenna is an insulating plastic medium with a metal film on its surface. The stacked substrates and the internal transmission grooves, through holes and other structures form a waveguide structure for signal transmission. The weight of the waveguide antenna can be reduced without affecting the signal pass rate, and the processing cost can be reduced. The waveguide antenna can be widely used in engineering.

Furthermore, transmission grooves are designed on both sides of each substrate. The transmission groove of each substrate cooperates with the transmission groove on the adjacent substrate, and the size meets the design requirements of the waveguide millimeter wave electromagnetic field. The transmission grooves between these substrates form an air waveguide. The waveguide port of the bottom substrate can match the port of the microstrip waveguide converter, and the waveguide port of the top layer radiates electromagnetic waves into the free space. The holes and slots on the middle substrate realize multi-port distribution or synthesis of the waveguide, as well as waveguide length matching, so as to configure the signal to each antenna array element.

The antenna signal transmission device of the present invention includes a waveguide antenna and a signal converter. It can transmit electromagnetic waves of multiple frequency bands to free space or receive electromagnetic waves of different frequency bands in free space through a coupled antenna array. It has a wide operating frequency band, a simple structure, and is easy to mass produce.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

FIG1 is a side cross-sectional view of a waveguide antenna according to an embodiment of the present application;

FIG2 is an end view of a waveguide antenna according to an embodiment of the present application;

FIG3 is a top view of a waveguide antenna according to an embodiment of the present application;

FIG4 is a bottom view of a waveguide antenna according to an embodiment of the present application;

FIG. 5 is a side cross-sectional view of a signal conversion device according to an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application are clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. In the absence of conflict, the following embodiments and their technical features can be combined with each other.

The present invention will be described more clearly and completely below through embodiments in conjunction with the accompanying drawings.

Please refer to FIG. 1 , which is a side cross-sectional view of a waveguide antenna according to an embodiment of the present invention.

In this embodiment, the waveguide antenna 1 includes a first substrate 2, a second substrate 3, an intermediate substrate 4 and an antenna substrate 5; the first substrate 2, the second substrate 3, the intermediate substrate 4 and the antenna substrate 5 all include relative first surfaces and second surfaces, and the substrates are stacked in sequence, with the first surface of the upper substrate stacked on the second surface of the lower substrate.

The first substrate 2 includes a waveguide port 201 and a first transmission slot 202, and the waveguide port 201 is connected to the first transmission slot 202. The second substrate 3 includes a second transmission slot 301 located on one side of the first surface of the second substrate 3, a third transmission slot 303 located on one side of the second surface of the second substrate 3, and a first transmission through hole 302 connecting the second transmission slot 301 and the third transmission slot 303. The sizes of the second transmission slot 301 and the first transmission slot 202 match, and the opening edges are aligned to form the transmission waveguide 9.

Please refer to Figures 2 and 4, where Figure 2 is a schematic cross-sectional view of the inner portion of the waveguide perpendicular to the substrate surface, and Figure 4 is a schematic bottom view of the waveguide antenna at the first surface of the first substrate 2. In this embodiment, the waveguide opening 201 is rectangular. In other embodiments, the waveguide opening 201 may also be circular, ridge-shaped, triangular or elliptical, etc., as long as the pass rate of signal transmission is satisfied. The transmission waveguide 9 is a rectangular waveguide, and the cross section perpendicular to the signal transmission direction is rectangular. In other embodiments, the transmission waveguide 9 may also be a cylindrical waveguide, etc.

The length a and width b of the cross section of the waveguide port 201 and the transmission waveguide 9 satisfy: a=0.7λ, b=(0.4-0.5)λ, wherein a is the side length parallel to the first surface of each substrate, and b is the side length perpendicular to the first surface of each substrate.

The transmission waveguide 9 can be designed to have different lengths to meet the phase design requirements of the waveguide phased array antenna. The waveguide length GL of the transmission waveguide 9 is _GL = P*λ _g /360.00, where λ _g is the waveguide wavelength of the transmission _waveguide 9 and P is the phase of the transmission signal. λ ₀ is the working center frequency wavelength, and ε _r is the dielectric constant of the substrate of the waveguide antenna 1.

The intermediate substrate 4 includes a first surface and a second surface that are opposite to each other; a fourth transmission groove 401 is provided on the first surface side of the intermediate substrate 4, and a fifth transmission groove 404 and a sixth transmission groove 405 are provided on the second surface side; the fourth transmission groove 401 is connected to the fifth transmission groove 404 through the second transmission through hole 402, and the fourth transmission groove 401 is connected to the sixth transmission groove 405 through the third transmission through hole 403.

The third transmission slot 303 of the second substrate 3 and the fourth transmission slot 401 of the intermediate substrate 4 constitute a first power divider 6 for distributing the signal received by the third transmission slot 303 to the fifth transmission slot 404 and the sixth transmission slot 405 .

The antenna substrate 5 includes a first surface and a second surface opposite to each other. The opening 501 of the antenna substrate 5 is located on the second surface side of the antenna substrate 5. The antenna substrate 5 also includes a seventh transmission slot 502 and an eighth transmission slot 503 located on the first surface side of the antenna substrate 5. The seventh transmission slot 502 and the eighth transmission slot 503 are connected to at least two of the openings 501. The fifth transmission slot 404 of the intermediate substrate 4 is connected to the seventh transmission slot 502 of the antenna substrate 5 to form a second power divider 7. The sixth transmission slot 405 of the intermediate substrate 4 is connected to the eighth transmission slot 503 of the antenna substrate 5 to form a third power divider 8, which is used to distribute the signals received by the fifth transmission slot 404 and the sixth transmission slot 405 to each of the openings 501. The openings 501 are antenna array elements, which are distributed on the second surface side of the antenna substrate 5 in a planar manner and are used to radiate signals to free space. The signal flow during reception is opposite to that during transmission. FIG3 is a schematic top view of the second surface side of the antenna substrate 5.

In this embodiment, the first substrate 2, the second substrate 3, the intermediate substrate 4 and the antenna substrate 5 all include an insulating layer and a metal film covering the surface of the insulating layer. The through holes, transmission slots, etc. in each substrate can be formed in one step by an injection molding process. In other embodiments, each through hole and transmission slot can also be formed by etching the insulating plate.

In this embodiment, the exposed insulating layer surface of each substrate has a metal film. The metal film is electroplated on the surface of the first substrate 2, the second substrate 3, the intermediate substrate 4 and the antenna substrate 5. The substrates coated with the metal film are stacked and assembled to form the above-mentioned waveguide antenna structure.

In other embodiments, the main insulating layers of each substrate may be stacked and assembled first, and then a metal film may be formed on the surface so that the metal film at least covers the waveguide port 201, the transmission waveguide 9, the signal transmission path in the intermediate substrate, and the inner wall surface of the antenna array element.

In other embodiments, other methods may be used to cover the inner wall surface and the outer surface with a uniform metal film, as long as the electromagnetic wave signal is gathered to form an electromagnetic shield.

In this embodiment, the metal film is an aluminum film with a thickness of 1/200 of the wavelength of the center frequency of the working frequency band. In other embodiments, the metal film can also be a metal material with high conductivity such as gold, silver, copper and tin. Preferably, a metal material with a conductivity greater than 10s/cm is selected, and the thickness of the metal film is 1/200 of the wavelength of the center frequency of the working frequency band.

In this embodiment, the main insulating layers of the first substrate 2, the second substrate 3, the intermediate substrate 4 and the antenna substrate 5 of the waveguide antenna 1 are all injection molding materials with good insulation, voltage resistance, tensile strength and heat deformation temperature. For example, at least one of polyphenylene sulfide, phenolic plastic, polyurethane plastic, epoxy plastic and unsaturated polyester plastic can be used. In one embodiment, the insulating layer is made of PPS (polyphenylene sulfide) material with a tensile strength of 160MPa, a heat deformation temperature of 260° and a withstand voltage of 24MV/m at room temperature. In other embodiments, the insulating layer can also be other materials with good insulation, and the heat deformation temperature of the material is higher than 150°C and the tensile strength is greater than 80MPa.

In this embodiment, at least one side wall of the fifth transmission slot 404 of the second power divider 7 and the sixth transmission slot 405 of the third power divider 8 is a stepped structure to meet the requirements of antenna beam shape and antenna gain.

In this embodiment, the waveguide antenna further includes a positioning pin and a positioning hole, and the positioning pin and the positioning hole are respectively located on the surfaces of the adjacent substrates on both sides, and the positioning pin is embedded in the positioning hole. Specifically, the first surface side of the second substrate 2 has a protruding first positioning pin 203, which is embedded in the positioning hole on the first surface of the first substrate 1; the second surface side of the intermediate substrate 4 has a protruding second positioning pin 304, which is embedded in the positioning hole on the first surface of the second substrate 3; the first surface of the antenna substrate has a third positioning pin 408, which is embedded in the positioning hole on the first surface of the intermediate substrate 4. The positioning holes and positioning pins that are matched in position make it easy to assemble the various substrates. By setting pin holes in different positions on each stacking surface, the installation error of the substrate position can be avoided, and the hole and slot structure positions between the various substrates can be aligned. In other embodiments, assembly and positioning can also be achieved by setting other positioning structures between adjacent substrates, such as setting jacks, bayonet ports, card slots, etc.

Furthermore, the substrates can be bonded to each other by a glue-dispensing bonding process to form a fixed stack. In other embodiments, other forms of fixing the substrates can also be used as long as the normal use of the waveguide antenna 1 can be guaranteed.

In this embodiment, the first power divider 6, the second power divider 7 and the third power divider 8 are all one-to-two waveguide power dividers, which are used to evenly divide the received signal into two signal outputs. In other embodiments, the first power divider 6, the second power divider 7 and the third power divider 8 can also be one-to-three waveguide power dividers, one-to-four waveguide power dividers, etc., on the premise of meeting the requirements of the waveguide antenna 1, as long as the requirements of evenly dividing the transmission signal can be met, and the number and position of the openings 501 can be adjusted as appropriate.

In other embodiments, there may be more than two layers of intermediate substrates between the second substrate 3 and the antenna substrate 5, and each intermediate substrate stacking structure may form a signal transmission path through transmission holes, transmission slots, etc., and the signal transmission path may have an input port and several output ports, and several power dividers connecting the input port and the output port, for connecting the input port to each output port. The output port is connected to the antenna array element, and the input port is connected to the transmission waveguide 9.

In the above embodiment, the waveguide antenna array element 501 is a waveguide antenna with four antenna array elements. The input signal is transmitted to the transmission waveguide 9 through the waveguide port 201 to transmit the modulated signal to the first power divider 6 and output two signals with the same phase. The signal is then divided into four signals with the same phase by the first power divider 7 and the first power divider 8 to form a waveguide antenna array element 501, and radiate electromagnetic field signals to space through the opening. In other embodiments, the waveguide antenna array element 501 can also be eight waveguide antenna array elements, sixteen waveguide antenna array elements, etc. The number of the waveguide antenna array elements 501 of the antenna substrate 1 is the same as the number of output ports of the intermediate substrate 4. The signal can be distributed to each antenna array element by adjusting the distribution capacity and number of the power dividers on the signal transmission path in the waveguide antenna.

Please refer to FIG. 5 , which is a schematic diagram of the structure of a signal conversion device according to an embodiment of the present invention.

In this embodiment, the signal conversion device includes a waveguide antenna 1 and a signal converter 10 .

The waveguide antenna 1 is as described in the above embodiment and will not be described again herein.

In this embodiment, the signal converter 10 is used to generate an electromagnetic field signal and transmit it to the waveguide port 201 of the waveguide antenna 1 .

The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structural or equivalent process transformations made using the contents of the specification and drawings of the present application, such as the mutual combination of technical features between the embodiments, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims (10)

1. A waveguide antenna, comprising: A first substrate, comprising a waveguide opening located on a side surface; A second substrate is stacked on the first substrate, wherein a transmission waveguide is provided in the stacked structure formed by the second substrate and the first substrate, and one end of the transmission waveguide is connected to the waveguide port; At least one intermediate substrate is stacked on the second substrate, a signal transmission path is formed in the stacked structure formed by the at least one intermediate substrate, the signal transmission path has an input port and a plurality of output ports, and a plurality of power dividers connecting the input port and the output ports, and used to connect the input port to each output port; An antenna substrate, stacked on the intermediate substrate, wherein a plurality of openings are provided in the antenna substrate, and the openings serve as waveguide antenna array elements and are connected to each of the output ports; The first substrate, the second substrate, the intermediate substrate and the antenna substrate all include an insulating layer and a metal film covering at least part of the surface of the insulating layer; the inner wall surfaces of the waveguide port, the transmission waveguide and the signal transmission path are all formed with the metal film, and the thickness of the metal film is 1/200 of the wavelength of the center frequency of the working frequency band; The first substrate has a first surface and a second surface opposite to each other, the waveguide port is located on the first surface side, the first substrate also includes a first transmission slot located on the second surface side, and the waveguide port is connected to the first transmission slot; the second substrate has a first surface and a second surface opposite to each other, including a second transmission slot located on the first surface side of the second substrate, the second transmission slot is connected to the first transmission slot, and the opening edges are aligned to form the transmission waveguide; The second substrate further includes: a third transmission slot located on one side of the second surface of the second substrate, and a first transmission through hole located between the second transmission slot and the third transmission slot and connecting the second transmission slot and the third transmission slot; The intermediate substrate comprises a first surface and a second surface opposite to each other; the first surface side of the intermediate substrate has a fourth transmission slot, and a fifth transmission slot and a sixth transmission slot are formed on the second surface side of the intermediate substrate, the fourth transmission slot is connected to the fifth transmission slot through a second transmission hole, and the fourth transmission slot is connected to the sixth transmission slot through a third transmission hole; the third transmission slot of the second substrate and the fourth transmission slot of the intermediate substrate constitute a first power divider for distributing the signal received by the third transmission slot to the fifth transmission slot and the sixth transmission slot; The antenna substrate includes a first surface and a second surface relative to each other, the opening of the antenna substrate is located on the second surface side of the antenna substrate, and the antenna substrate also includes a seventh transmission slot and an eighth transmission slot located on the first surface side of the antenna substrate, and the seventh transmission slot and the eighth transmission slot are connected to at least two of the openings; the fifth transmission slot of the intermediate substrate is connected to the seventh transmission slot of the antenna substrate to form a second power divider, and the sixth transmission slot of the intermediate substrate is connected to the eighth transmission slot of the antenna substrate to form a third power divider, which is used to distribute the signals received by the fifth transmission slot and the sixth transmission slot to each of the openings. 2 . The waveguide antenna according to claim 1 , wherein the material of the metal film comprises at least one of gold, silver, copper, aluminum and tin. 3 . The waveguide antenna according to claim 1 , wherein the conductivity of the metal film is greater than 10 s/cm. 4 . The waveguide antenna according to claim 1 , wherein the material of the insulating layer comprises at least one of polyphenylene sulfide, phenolic plastic, polyurethane plastic, epoxy plastic and unsaturated polyester plastic. 5 . The waveguide antenna according to claim 1 , wherein the cross-section of the transmission waveguide and the signal transmission path perpendicular to the signal transmission direction is rectangular. The waveguide antenna according to claim 1, characterized in that the waveguide length _GL of the transmission waveguide is _GL = P* _λg /360.00, wherein _λg is the waveguide wavelength of the transmission waveguide, and P is the phase of the transmission signal. 7. The waveguide antenna according to claim 1, characterized in that at least one side wall of the fifth transmission slot of the second power divider and the sixth transmission slot of the third power divider is a stepped structure. 8. The waveguide antenna according to claim 1 is characterized in that it also includes a positioning pin and a positioning hole, wherein the positioning pin and the positioning hole are respectively located on the surfaces of the adjacent substrates that are bonded on both sides, and the positioning pin is embedded in the positioning hole. 9. The waveguide antenna according to claim 1 or 8, characterized in that adjacent substrates are bonded together by glue. 10. A signal transmission device, comprising: The waveguide antenna according to any one of claims 1 to 9; A signal converter, wherein the signal converter is connected to the waveguide port, and the signal converter is used to generate electromagnetic waves and transmit them to the waveguide antenna.