CN107959113B

CN107959113B - Dual-polarized antenna

Info

Publication number: CN107959113B
Application number: CN201711417406.XA
Authority: CN
Inventors: 桂万如; 季文涛; 邓庆勇; 陈士兵
Original assignee: Hefei Rhosoon Intelligent Technology Co ltd
Current assignee: Hefei Rhosoon Intelligent Technology Co ltd
Priority date: 2017-12-25
Filing date: 2017-12-25
Publication date: 2023-10-20
Anticipated expiration: 2037-12-25
Also published as: CN107959113A

Abstract

The invention discloses a dual-polarized antenna which comprises a main reflector, a feed source array, an auxiliary reflector and a mounting frame. The mounting frame is used for mounting the feed source array on the main reflecting surface of the main reflecting member, and the auxiliary reflecting member is further mounted above the feed source array, so that the auxiliary reflecting surface of the auxiliary reflecting member is parallel to the feed source array, the center of the auxiliary reflecting surface and the center of the feed source array are positioned on the same straight line, and the feed source array is positioned at the focus of the main reflecting surface. The mounting bracket includes: one end of the upright post is vertically fixed at the center of the main reflecting surface; a slot fixed on the other end of the upright post and positioned at the focus of the main reflecting surface; a plurality of first positioning parts which are welded on the secondary reflecting surface and are circularly distributed by taking the center of the secondary reflecting surface as the center of a circle; a plurality of second positioning parts which are welded on the bottom surface of the slot and are circularly distributed by taking the center of the feed source array as the center of a circle; a plurality of support rods with one end fixed on one positioning part I and the other end fixed on the other positioning part II. The feed source array is mounted on the slot.

Description

Dual-polarized antenna

Technical Field

The invention relates to an antenna in the fields of microwave communication and satellite-ground communication, in particular to a dual-polarized antenna.

Background

The antenna is formed by using a metal reflecting surface and a feed source as main components, mainly comprises a single reflecting surface antenna and a double reflecting surface antenna, is an antenna form derived based on an optical principle, and is widely used for microwaves and wave bands with shorter wavelengths. A variety of single-reflector antennas have come into wide use around the second world war, and double-reflector antennas typified by cassegrain antennas have emerged by the 60 s. They have become the most commonly used type of microwave and millimeter wave high gain antennas, and are widely used in the technical fields of communication, radar, radio navigation, electronic countermeasure, telemetry, radio astronomy, weather, etc. Taking satellite communication as an example, the reflecting surface antenna is a main antenna form of a communication satellite earth station due to high gain and simple structure; it is also the basic form of spacecraft and satellite antennas, since it can be made into an expandable folded umbrella structure. Not only have various reflecting surface forms been produced so far to meet different needs, but also various feed structures with excellent performance have appeared.

Communication-in-motion is an abbreviation for "satellite ground station communication system in motion". The satellite-to-ground communication in motion is a new application generated for meeting the requirement of a user for transmitting broadband video information in dynamic movement through a satellite, and the mobile communication is performed by using the Ku frequency band of a fixed orbit satellite to transmit the broadband information, so that the satellite-to-ground communication in motion is an emerging service application. Through the communication-in-motion system, a vehicle, a ship, an airplane and other mobile carriers can track a satellite and other platforms in real time in the motion process, and can continuously transmit voice, data, images and other multimedia information, so that the requirements of various military and civil emergency communication and multimedia communication under mobile conditions can be met.

Currently, the "in-motion" system mainly uses the Ku band to communicate with fixed-orbit satellites. According to the document requirements of the general technical requirements of the vehicle-mounted satellite communication earth station used in the stationary of the Ku frequency band, the general technical requirements of the portable satellite communication earth station of the Ku frequency band and the like published in 2014 of China, a Ku wave band communication-in-motion system is required to be composed of an application subsystem, a power subsystem, a channel subsystem, an antenna, a control system of the antenna and the like. The antenna system needs to cover uplink/downlink frequency bands simultaneously, wherein the uplink frequency band is 13.75-14.5 GHz, the downlink frequency band is 10.95-11.75 GHz and 12.25-12.75 GHz, and the polarizations of the uplink frequency band and the downlink frequency band are two orthogonal linear polarizations. In order to ensure smooth communication between the satellite and the ground mobile device, the system antenna needs to be pointed to the communication satellite in real time. In order to avoid interference to adjacent satellites when the antenna is transmitting, the tracking error of the antenna in motion of the mobile device is usually required to be less than 0.1 degrees, the feed source also performs rotation tracking, and the polarization isolation between the receiving and transmitting is more than 30dB. In addition, corresponding requirements are also put on the transmitting power, side lobe level and the like of the antenna in the document.

At present, a plurality of enterprise units at home and abroad have proposed products related to 'communication in motion', such as a plurality of groups of patch antennas proposed by RaySat company in israel, IMVS450M products proposed by TracStar in the U.S., mijet series products proposed by Starling company in israel, 0.5M and 1.2M vehicle-mounted loop focal antennas developed by domestic electric group 54, and the like. In order to meet the requirement of the antenna on the high-precision real-time tracking alignment of the satellite, the 'communication in motion' products all comprise an automatic tracking system. The automatic tracking system is that under the initial static condition, the GPS, theodolite and strapdown inertial navigation system measure the course angle, longitude and latitude of the carrier position and initial angle relative to the horizontal plane, then automatically determine the antenna elevation angle based on the horizontal plane according to the attitude, geographic position and satellite longitude, rotate the azimuth on the premise of keeping the elevation angle unchanged to the horizontal plane, and automatically aim at the satellite in a signal maximum mode. In the carrier movement process, the change of the carrier posture is measured, the carrier posture is converted into the error angle of the antenna through the operation of a mathematical platform, the azimuth angle, the pitch angle and the polarization angle of the antenna are adjusted through a servo mechanism, the antenna pair star is ensured to be in a specified range in the carrier movement process, and the satellite transmitting antenna tracks the geosynchronous satellite in real time in the carrier movement. The tracking mode of the system comprises two modes of self-tracking and inertial navigation tracking. The self-tracking is to rely on satellite beacons to perform antenna closed loop servo tracking; the inertial navigation tracking is to utilize the change of the gyro inertial navigation combined sensitive carrier to carry out antenna tracking. The two kinds of tracking can be automatically switched according to the field condition. When the system finishes the star alignment and automatically tracks, the system works in a self-tracking mode; meanwhile, the inertial navigation system also enters a working state and continuously outputs data such as antenna polarization, azimuth and pitching. When the antenna beacon signal is interrupted due to occlusion or other reasons, the system automatically switches to the inertial tracking mode.

Regardless of the tracking mode adopted by the antenna, a high-precision servo system is always one of key parts of a traditional 'communication-in-motion' system. In general, the high-precision servo system needs to have high tracking precision of about 0.1 degrees, and meanwhile, the "communication-in-motion" antenna has a larger caliber (the caliber of the antenna meeting the network access requirement currently exceeds 1 meter) and weight, so that the high-precision servo system has higher cost. At present, the high-precision servo system applied to the communication in motion takes tens of thousands, even more than one hundred thousands, which accounts for a large part of the cost of the whole communication in motion, and the wide application of the communication system in motion in the civil field is limited.

In the current satellite communication antenna, the auxiliary reflection piece is additionally arranged according to the environmental requirement, and when the auxiliary reflection piece is additionally arranged, the auxiliary reflection surface of the auxiliary reflection piece is required to be ensured to face the feed source array and face the upper air field of the feed source array. Thus, a mount for mounting the secondary reflector on the slot of the feed array is required, and: the secondary reflecting surface of the secondary reflecting piece is parallel to the feed source array, and the center of the secondary reflecting surface and the center of the feed source array are positioned on the same straight line. Otherwise, larger communication data errors are easy to occur, so that tool errors during assembly are required to be reduced, and stability of the auxiliary reflecting piece relative to the feed source array in the long-term use process is ensured.

Disclosure of Invention

In view of the above, the invention provides a dual-polarized antenna, the feed source array of the invention is matched with the main reflecting surface, so that the antenna system can scan and track the electronic beam of a satellite at a small angle, at a high speed and with high precision, and by adopting the technology, the requirements on the precision and the dynamic response speed of the servo system can be reduced, thereby reducing the cost of the servo system; furthermore, the invention can reduce the tool error when the auxiliary reflector is assembled on the upper part of the feed source array, and ensure the stability of the auxiliary reflector relative to the feed source array in the long-term use process.

The solution of the invention is as follows: a dual-polarized antenna comprises a main reflector, a feed source array, an auxiliary reflector and a mounting frame; the mounting frame is used for mounting the feed source array on the main reflecting surface of the main reflecting member, and the auxiliary reflecting member is also arranged above the feed source array, so that the auxiliary reflecting surface of the auxiliary reflecting member is parallel to the feed source array, the center of the auxiliary reflecting surface and the center of the feed source array are positioned on the same straight line, and the feed source array is positioned at the focus of the main reflecting surface;

the mounting frame comprises a stand column, a slot, a plurality of first positioning parts, a plurality of second positioning parts and a plurality of support rods; one end of the upright post is vertically fixed at the center of the main reflecting surface, the slot is fixed at the other end of the upright post and positioned at the focus of the main reflecting surface, and the feed source array is arranged on the slot; the first positioning parts are welded on the secondary reflecting surface and are distributed in an annular mode by taking the center of the secondary reflecting surface as the center of a circle; the second positioning parts are welded on the bottom surface of the slot and are distributed in an annular mode by taking the center of the feed source array as the center of the circle, the second positioning parts are respectively corresponding to the first positioning parts one by one, the second positioning parts and the corresponding first positioning parts are located on the same plane, and the plane where the second positioning parts are located is perpendicular to the auxiliary reflecting surface; one end of each supporting rod is fixed on one of the first positioning parts, and the opposite other end of each supporting rod is fixed on one of the second positioning parts; each supporting rod is of a sheet-shaped structure which is bent for many times, and the two ends of each supporting rod are arranged up and down oppositely and are parallel to each other;

the feed source array comprises an upper layer circuit board, a middle layer circuit board and a bottom layer circuit board which are sequentially arranged from top to bottom; the upper layer circuit board, the middle layer circuit board and the bottom layer circuit board are fixed at intervals and are parallel to each other; the bottom circuit board is a microstrip reflecting plate with a metal floor, and a plurality of transmitting antenna feed ports and receiving antenna feed ports are formed in the bottom circuit board; the middle layer circuit board is a microstrip antenna structure, the front and the back of the middle layer circuit board are divided into a plurality of areas by a latticed metal strip circuit, and the latticed metal strip circuit on the front and the back is conducted with each other through a metallized through hole; the upper circuit board is a dielectric board; the bottom side of the bottom layer circuit board is attached with a conductor;

the space between the middle layer circuit board and the bottom layer circuit board is 0.1-0.3 lambda, the space between the upper layer circuit board and the middle layer circuit board is 0.3-0.7 lambda, lambda is the free space wavelength corresponding to the working frequency; the front of each area of the middle layer circuit board is provided with a metal dipole serving as a receiving antenna, a receiving antenna feed pad and a transmitting antenna feed pad, the back of each area is provided with a metal dipole serving as a transmitting antenna, the receiving antenna feed pad is connected with the receiving antenna, the transmitting antenna feed pad is connected with the transmitting antenna, and the receiving antennas and the transmitting antennas in the areas corresponding to the front and the back are arranged in a 90-degree crossed mode.

As a further improvement of the scheme, the mounting frame further comprises a base, the base is fixed at the circle center of the main reflecting surface, and the upright post is vertically fixed on the base.

As a further improvement of the scheme, the base is fixed at the center of the main reflecting surface through a plurality of fasteners; the slot and the upright post are cylindrical, and the diameter of the upright post is smaller than that of the slot.

As a further improvement of the scheme, one end of each support rod fixing positioning part I extends in parallel along the edge of the auxiliary reflection surface, extends out of the auxiliary reflection surface, bends downwards, extends to the positioning part II, bends and extends to the corresponding positioning part II in parallel along the bottom surface.

As a further improvement of the scheme, one end of each supporting rod fixing and positioning part I extends in parallel along the edge of the auxiliary reflecting surface, extends out of the auxiliary reflecting surface, bends downwards and extends vertically, bends towards the positioning part II and extends to the positioning part II, bends towards the positioning part II and extends to the corresponding positioning part II in parallel along the bottom surface.

As a further improvement of the above solution, the mounting frame further comprises a plurality of fasteners, and each support rod is fixed to the corresponding first positioning portion by at least one fastener and also fixed to the corresponding second positioning portion by at least another fastener.

Further, the support rod is positioned on the same side of the corresponding first positioning part and the corresponding second positioning part, and one side of the support rod is attached to the corresponding first positioning part and the corresponding second positioning part.

As a further improvement of the scheme, 4 feed holes are formed in the bottom layer circuit board along the radial direction, 2 feed holes are further formed in two sides of the 4 radial feed holes respectively, 8 feed holes are formed in total, four feed holes are feed holes of the transmitting antenna, and four feed holes of the receiving antenna.

As a further improvement of the scheme, a plurality of first nylon studs are arranged between the upper layer circuit board and the middle layer circuit board, the middle shaft holes of the first nylon studs are respectively aligned with the fixing holes on the upper layer circuit board and the fixing holes on the middle layer circuit board, a plurality of second nylon studs are arranged between the middle layer circuit board and the bottom layer circuit board, and the middle shaft holes of the second nylon studs are respectively aligned with the fixing holes on the middle layer circuit board and the fixing holes on the bottom layer circuit board.

Preferably, the nylon screws I are screwed into the nylon studs I after downwards penetrating through the fixing holes on the upper circuit board from the upper part of the upper circuit board, the nylon screws II are screwed into the nylon studs I after upwards penetrating through the fixing holes on the bottom circuit board, the nylon screws Long Luozhu II and the fixing holes on the middle circuit board in sequence from the bottom of the bottom circuit board, and therefore the upper circuit board, the middle circuit board and the bottom circuit board are fixed together.

Compared with the prior art, the invention has the following advantages:

1. the designed antenna feed source array can be conveniently applied to a satellite communication antenna with a single reflection surface or a double reflection surface, and realizes small-angle, high-speed and high-precision beam tracking and scanning so as to reduce the requirements on the precision and dynamic speed of a mechanical servo system, thereby reducing the cost of an antenna system and promoting the application of a 'communication-in-motion' system in the civil field;

2. the feed source applicable to the 'communication in motion' antenna is realized by adopting the principle of a printed metal cross dipole structure and a 'Fabry-Perot' antenna; compared with the traditional feed source structures such as a waveguide port, a waveguide loudspeaker and the like, the feed source structure is simple and compact, so that a plurality of units and receiving/transmitting channels can be realized in a smaller area, and the higher-precision beam pointing control required by the communication-in-motion antenna is facilitated;

3. the cancellation technology can realize 30dB isolation between the receiving/transmitting channels at the same position at the antenna structure end, thereby reducing the pressure of the rear-end device;

4. the feed source adopts a microstrip printed circuit board structure, has mature process, simple processing and lower cost, and is suitable for mass production;

5. the mounting frame is adopted, the fixing mode of the first locating part on the auxiliary reflecting surface and the fixing mode of the second locating part on the bottom surface ensure the stable connection between the feed source array and the auxiliary reflecting piece; the first positioning part is circularly distributed by taking the center of the secondary reflecting surface as the center of the circle, the second positioning part is circularly distributed by taking the center of the feed source array as the center of the circle, and the plane where the second positioning part and the corresponding first positioning part are positioned is perpendicular to the secondary reflecting surface, so that the secondary reflecting surface of secondary reflection can be ensured to be parallel to the feed source array, and the center of the secondary reflecting surface and the center of the feed source array are ensured to be positioned on the same straight line. Therefore, the invention can reduce the tool error when the auxiliary reflector is assembled on the upper part of the feed source array, and ensure the stability of the auxiliary reflector relative to the feed source array in the long-term use process.

Drawings

Fig. 1 is a schematic diagram of the overall structure of a cassegrain antenna to which the dual-polarized antenna of the present invention is applied.

Fig. 2 is a schematic perspective view of the sub-reflector and feed array of fig. 1 assembled using a mounting bracket.

Fig. 3 is an enlarged partial schematic view of fig. 2.

Fig. 4 is a side view of a dual polarized antenna feed array of the present invention.

Fig. 5 is an exploded perspective view of a dual-polarized antenna feed array of the present invention.

Fig. 6 is a schematic top view of the underlying circuit board of the dual-polarized antenna feed array of the present invention.

Fig. 7 is a side cross-sectional view of the underlying circuit board of fig. 6.

Fig. 8 is a schematic top view of the intermediate layer circuit board of the dual-polarized antenna feed array of the present invention.

Fig. 9 is a bottom view of the intermediate layer circuit board of fig. 8.

Fig. 10 is a side cross-sectional view of the intermediate layer circuit board of fig. 8.

Fig. 11 is a schematic top view of the upper circuit board of the dual-polarized antenna feed array of the present invention.

Fig. 12 is a side cross-sectional view of the upper circuit board of fig. 11.

Fig. 13 is a graph of return loss simulation results for a dual-polarized antenna feed array of the present invention.

Fig. 14 is a graph showing the actual measurement results of the receiving port and the transmitting port of the dual-polarized antenna feed array of the present invention.

Fig. 15 is a simulated array receiving directivity diagram of the dual-polarized antenna feed array of the present invention at an operating frequency of 12.5GHz and within 0 ° of the azimuth plane and 90 ° of the azimuth plane.

Fig. 16 is a diagram of the measured array receiving directivity of the dual-polarized antenna feed array of the present invention at an operating frequency of 12.5GHz and in azimuth 0 ° and azimuth 90 °.

Fig. 17 is a simulated array emission directivity diagram of a dual-polarized antenna feed array of the present invention at an operating frequency of 14.1GHz and within 0 ° of the azimuth plane and 90 ° of the azimuth plane.

Fig. 18 is a graph of the measured array emission directivity of the dual-polarized antenna feed array of the present invention at an operating frequency of 14.1GHz and within 0 ° of the azimuth plane and 90 ° of the azimuth plane.

Detailed Description

The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

The dual-polarized antenna of the present invention is applied to the cassegrain antenna shown in fig. 1, which is applied to the in-motion communication, and includes a main reflecting member 3 in addition to the dual-polarized antenna. The dual-polarized antenna comprises a feed source array 2, a secondary reflector 1 and a mounting frame. The feed array 2 is fixed to the main reflecting surface of the main reflector 3, and the center of the feed array 2 is placed at the focal point of the cassegrain type antenna.

Referring to fig. 2 and 3 together, the mounting frame mounts the sub-reflector 1 above the feed source array 2, and the mounting frame can ensure that the sub-reflecting surface 75 of the sub-reflector 1 is parallel to the feed source array 2, and that the center of the sub-reflecting surface 75 and the center of the feed source array 2 are located on the same straight line, and that the feed source array 2 is located at the focus of the main reflecting surface 710. .

The mounting frame comprises a base 711, a column 712, a slot 73, a plurality of first positioning parts 74, a plurality of second positioning parts 76, a plurality of support rods 78 and a plurality of fasteners 79. One end of the upright post 712 is vertically fixed at the center of the main reflecting surface 710, the slot 73 is fixed on the other end of the upright post 712 and is positioned at the focus of the main reflecting surface 710, and the feed source array 2 is installed on the slot 73. In this embodiment, the base 711 is fixed at the center of the main reflecting surface 710, the upright post 712 is vertically fixed on the base 711, and the base 711 is fixed at the center of the main reflecting surface 710 by a plurality of fasteners. Both slot 73 and post 712 may be cylindrical, with the diameter of post 712 being smaller than the diameter of slot 73.

The number of the first positioning portion 74, the second positioning portion 76, and the supporting rod 78 generally corresponds, and in other embodiments, the number of the first positioning portion 74 and the second positioning portion 76 may be greater than the number of the supporting rod 78, respectively. There is no particular limitation on the number of the fasteners 79 as long as the devices to be fixed can be fixed, and each device can be added with fasteners as appropriate according to the time installation environment at the time of fixation.

The first positioning portions 74 are welded on the secondary reflecting surface 75, are circularly arranged by taking the center of the secondary reflecting surface 75 as the center, the second positioning portions 76 are welded on the bottom surface 77 of the slot 73, are circularly arranged by taking the center of the feed source array 2 as the center, the second positioning portions 76 are respectively in one-to-one correspondence with the first positioning portions 74, the second positioning portions 76 and the corresponding first positioning portions 74 are positioned on the same plane, and the plane is perpendicular to the secondary reflecting surface 75.

One end of each supporting rod 78 is fixed on one of the positioning parts 74, the other opposite end of each supporting rod 78 is fixed on one of the positioning parts 76, each supporting rod 78 is of a multi-bending sheet structure, and two ends of each supporting rod 78 are arranged up and down oppositely and are parallel to each other. The structural design of the support bar 78 reduces the impact of the inventive mount on the reflective properties of the secondary reflector 1 and the feedback properties of the feed array 2, as well as on the primary reflecting surface of the antenna. Therefore, the first positioning portions 74 are uniformly distributed on the sub-reflection surface 75 as much as possible, and the second positioning portions 76 are uniformly distributed on the bottom surface 77 as much as possible.

The support rod 78 is fixed on the secondary reflecting surface 75 through the first positioning part 74, and the support rod 78 is fixed on the bottom surface 77 through the second positioning part 76, so that the stable connection between the feed source array 2 and the secondary reflecting piece 1 is ensured. The first positioning part 74 is circularly arranged by taking the center of the secondary reflecting surface 75 as the center, the second positioning part 76 is circularly arranged by taking the center of the feed source array 2 as the center, and the plane where the second positioning part 76 and the corresponding first positioning part 74 are positioned is perpendicular to the secondary reflecting surface 75, so that the secondary reflecting surface 75 of the secondary reflecting member 1 can be ensured to be parallel to the feed source array 2, and the center of the secondary reflecting surface 75 and the center of the feed source array 2 are ensured to be positioned on the same straight line.

One end of each support rod 78, which fixes the first positioning portion 74, may extend in parallel along the edge of the secondary reflecting surface 75, extend out of the secondary reflecting surface 75, bend downward and extend to the second positioning portion 76, bend and extend in parallel along the bottom surface 77 to the corresponding second positioning portion 76. In this embodiment, one end of each support rod 78 fixes the first positioning portion 74 and extends in parallel along the edge of the secondary reflecting surface 75, and extends out of the secondary reflecting surface 75, then bends downward and extends vertically, bends and extends toward the second positioning portion 76, bends after extending to the second positioning portion 76, and extends in parallel along the bottom surface 77 to the corresponding second positioning portion 76.

Each support bar 78 is secured to a respective one of the positioning portions 74 by at least one fastener 79. Each support bar 78 is secured to a respective second positioning portion 76 by at least one other fastener 79. The fasteners 79 may be screws, bolts, pins or the like for securing.

The advantage of the sheet-like structure of the support bar 78 is that the two ends of the support bar 78 can be connected with the first positioning portion 74 and the second positioning portion 76 in a stable manner. The support rods 78 are located on the same side of the first positioning portion 74 and the second positioning portion 76, and one side of the support rods 78 is attached to the first positioning portion 74 and the second positioning portion 76. The contact area between the two ends of the support rod 78 and the first and second positioning portions 74 and 76 is increased by the attachment manner.

Referring to fig. 4 and 5, the feed array 2 takes the form of a microstrip Printed Circuit Board (PCB) -based "fabry-perot" antenna, comprising an upper circuit board 16, a middle circuit board 17, and a lower circuit board 18, arranged in sequence from top to bottom. The upper circuit board 16, the middle circuit board 17 and the bottom circuit board 18 are fixed at intervals and parallel to each other, and can be locked by screws.

The three layers of circuit boards can be made on a dielectric copper-clad plate with a dielectric constant of 3, wherein the bottom layer of circuit board 18 is a microstrip reflecting plate with a metal floor, the middle layer of circuit board 17 is an antenna structure in a microstrip form, and the upper layer of circuit board 16 is a pure dielectric board with the effect of enhancing orientation. The thicknesses of the upper layer circuit board 16, the middle layer circuit board 17 and the bottom layer circuit board 18 are respectively 3mm, 0.5mm and 1.5mm, and the diameters are the same and are all 54mm. The three layers of circuit boards are connected with each other through four fixing holes which are identical in position and are rotationally symmetrical, the hole distance of the fixing holes at the opposite angles is 49mm, and the hole diameter is 2mm.

Referring to fig. 6 and 7, a conductor, such as copper, is attached to the bottom side of the bottom circuit board 18, and 4 fixing holes 4 are formed thereon, and 4 feeding holes 5 are radially provided. Two sides of the 4 radial feed holes 5 are also respectively provided with 2 feed holes 5, and a total of 8 feed holes 5 are arranged, wherein four feed holes are feed holes of the transmitting antenna, and four feed holes of the receiving antenna. The SSMA interface 24 is welded to the bottom circuit board 18 through the feed hole, the upper and lower ends of the SSMA interface extend out of the bottom circuit board 18, the hollow copper stand 6 is welded to the upper end of the bottom circuit board 18 through the feed hole, and the hollow copper stand covers the inner core of the SSMA interface 24. When the feed source array 2 is fixed on the main reflector 3 of the cassegrain antenna, a waist hole gasket 22 is arranged between the feed source array 2 and the main reflector 3, specifically, two ends of the waist hole gasket 22 are respectively provided with a through hole, and the waist hole gasket 22 is locked on the bottom layer circuit board 18 through one of through hole screws.

Referring to fig. 8, 9 and 10, the intermediate circuit board 17 is shown in schematic configuration, wherein fig. 8 is a top view, fig. 9 is a bottom view, and fig. 10 is a side sectional view. The middle layer circuit board 17 is provided with 4 fixing holes 7, the front side and the back side of the middle layer circuit board 17 are equally divided into 4 areas, the structures of all the areas on the front side are the same, specific parameters are slightly different, the structures of all the areas on the back side are the same, and specific parameters are slightly different.

For the convenience of processing and assembly, each area of the front and the back is provided with 1 dielectric plate window 11. To isolate the influence of the surface wave on the pattern, the front and back sides of the intermediate circuit board 17 are divided into 4 areas by the lattice-shaped metal strip circuits 14 with a certain opening structure 172, and the lattice-shaped metal strip circuits 14 on the front and back sides are mutually conducted by metallized through holes (not shown). Here, the openings in the latticed metal strip circuit 14 are introduced to avoid forming a closed resonant cavity so as not to deteriorate the matching characteristics of the antenna. The cross coupling between array elements is reduced by providing a metallized via structure and dividing the area in the circuit board using the latticed metal strip circuit 14 and the placement of the latticed metal strip circuit 14 isolates the surface waves in the medium.

The front side of each area is provided with a metal dipole as a receiving antenna 9, a receiving antenna feed pad 10, a transmitting antenna feed pad 8, respectively, and the back side of each area is provided with a metal dipole as a transmitting antenna 13. The receiving antenna feed pad 10 is connected with the receiving antenna 9, the transmitting antenna feed pad 8 is connected with the transmitting antenna 13, the receiving antenna 9 and the transmitting antenna 13 in the corresponding areas on the front and back face are arranged in a 90-degree crossed mode, the receiving antenna 9 and the transmitting antenna 13 respectively work in a receiving/transmitting (downlink/uplink) frequency band, the crossed metal dipole structure can correspondingly realize two orthogonal linear polarizations required by receiving/transmitting, and the arm lengths of the receiving antenna 9 and the transmitting antenna 13 are adjustable.

For convenience of soldering, the receiving antenna feed pad 10 and the transmitting antenna feed pad 8 are provided at one side. In order to further reduce the influence of the feed structure on the isolation between the receiving and transmitting, in the design, the receiving antenna 9 and the transmitting antenna 13 which are positioned on the front and back surfaces of the circuit board and are positioned on the same position, namely the two dipole structures at the same position, are connected through a section of printed fine wire, and meanwhile, a printed metal disc 12 for improving the isolation of the receiving and transmitting channels is also arranged. The diameter of the metal disc 12 is about 0.05λ to 0.2λ, which is located near the apex angle of the rectangular unit divided by the metal strip 14, and the distance between the center of the metal disc 12 and the two sides surrounding the corresponding apex angle is about 0.15λ to 0.35λ. Lambda is the free space wavelength corresponding to the operating frequency. By adjusting the parameters of the length, thickness, etc. of the thin wire, the size and position of the metal disc 12 can be adjusted to achieve high isolation between the transmit and receive by appropriate cancellation means.

The receiving antenna 9 and the transmitting antenna 13 in the structure all realize bottom coaxial feed through the SSMA interface 24. Wherein the two arms of the receiving antenna 9 and the transmitting antenna 13 are connected to the inner core and the outer wall of the SSMA interface 24, respectively, by a length of printed fine wire. The reason for the thin wires is here to reduce the effect of the feed structure on the isolation between the transmit and receive.

Referring to fig. 11 and 12, the upper circuit board 16 is provided with 4 fixing holes 15, and the upper circuit board 16 is a pure dielectric board with all copper-clad plates etched away, so as to form a "fabry-perot" upper structure.

As a preferred connection mode, 4 nylon studs 20 and 4 nylon studs 20 are arranged between the upper circuit board 16 and the middle circuit board 17, and the middle shaft holes of the nylon studs 20 are aligned with the fixing holes 15 and 7 on the upper circuit board 16 and the middle circuit board 17 respectively. And 4 nylon studs (21,4) are arranged between the middle layer circuit board (17) and the bottom layer circuit board (18), and the middle shaft holes of the nylon studs (21) are respectively aligned with the fixing holes (7) on the middle layer circuit board (17) and the fixing holes (4) on the bottom layer circuit board (18). The first nylon screws 19 penetrate through the fixing holes 15 on the upper circuit board 16 downwards from the upper part of the upper circuit board 16 and then are screwed into the first nylon studs 20, the second nylon screws 23 penetrate through the fixing holes 4, the second nylon studs 21 and the fixing holes 7 on the middle circuit board 17 on the bottom circuit board 18 upwards from the bottom of the bottom circuit board 18 and then are screwed into the first nylon studs 20, and therefore the upper circuit board 16, the middle circuit board 17 and the bottom circuit board 18 are fixed together.

In this feed structure, the spacing of the dielectric substrates has a direct effect on the operating bandwidth of the structure and the radiation gain. The suitable distance between the middle layer circuit board 17 and the bottom layer circuit board 18 is about 0.1λ -0.3λ, where λ is the free space wavelength corresponding to the operating frequency. When the distance between the two is too small, the gain of the feed source structure is higher, but the whole working bandwidth is too narrow; when the distance between the two is too large, the gain of the feed source structure is too low, the bandwidth is narrower, and the feed source physical structure is larger.

In addition, a suitable distance between the upper circuit board 16 and the intermediate circuit board 17 is about 0.3λ to 0.7λ. When the distance between the two is too large or too small, the gain of the feed source structure is too low, and the working bandwidth is narrow. In the feed source array structure, the distance between the upper circuit board 16, the middle circuit board 17 and the bottom circuit board 18 can be correspondingly adjusted by adjusting the height of the nylon bolts, so that the radiation gain of the structure can be conveniently adjusted to meet the requirements of different reflecting surface sizes and focal lengths.

In addition, by adjusting the arm length of the metal dipole, the operating frequency of the structure can be adjusted. Because of the structure operation and higher frequency, the dielectric substrate in the structure needs to have good high frequency characteristics. The dielectric constant, thickness, interval and other parameters of the dielectric substrate in the feed source structure have obvious influence on the overall working frequency band, working bandwidth, gain, inter-unit mutual coupling and the like of the structure, and comprehensive design and optimization adjustment are required to be emphasized in actual design.

The manufacturing method of the dual-linear polarized antenna comprises the following steps when the dual-linear polarized antenna is manufactured.

In step one, the center of the main reflecting surface 710 of the main reflecting member 3 is determined, and the mount 711 is fixed at the center of the main reflecting surface 710. To ensure that the center of the subsequent main reflector 3, the center of the feed source array 2 and the center of the secondary reflector 1 are positioned on the same straight line, a circular base 711 is selected as much as possible, and the center of the base 711 is positioned at the center of the main reflecting surface 710.

And secondly, one end of the upright post 712 is vertically fixed at the center of the base 711, the other end of the upright post is fixed with the slot 73, and the slot 73 is positioned at the focus of the main reflecting surface 710. This ensures that the feed array 2 inserted in the slot 73 is located at the focus of the primary reflective surface 710. To reduce assembly errors, the post 712 and the slot 73 may be assembled as a unit and then fixed to the base 711.

Step three, the feed source array 2 is inserted into the slot 73.

Fourth, the positioning portions 74 are welded on the secondary reflecting surface 75, and are arranged in a ring shape with the center of the secondary reflecting surface 75 as the center.

Fifth, the second positioning portions 76 are welded on the bottom surface 77 of the slot 73, and are circularly distributed with the center of the feed source array 2 as the center, the second positioning portions 76 are in one-to-one correspondence with the first positioning portions 74, the second positioning portions 76 and the first positioning portions 74 are located on the same plane, and the plane is perpendicular to the secondary reflecting surface 75.

Step six, one end of each supporting rod 78 is fixed on one of the first positioning parts 74, and the opposite end is fixed on one of the second positioning parts 76; the two ends of each support rod 78 are disposed opposite each other up and down and parallel to each other, wherein the center of the main reflector 3, the center of the feed source array 2, and the center of the sub reflector 1 are on the same line.

The fourth to sixth steps can be relatively adjusted, after the first positioning portions 74 are welded on the secondary reflecting surface 75, one end of each supporting rod 78 is fixed on one of the first positioning portions 74, and the secondary reflecting member 1, the first positioning portions 74 and the supporting rods 78 are assembled after being integrally formed, so that the installation is convenient and the assembly tolerance is reduced. Then, after the second positioning portions 76 are welded to the bottom surface 77 of the slot 73, the opposite end of each support rod 78 is fixed to one of the second positioning portions 76. In other embodiments, the base 711, the post 712, the second positioning portion 76, and the slot 73 may be integrally formed.

When the feed source array 2 is manufactured, the manufacturing method of the feed source array 2 comprises the following steps:

the middle shaft hole of the nylon stud 20 is aligned with the fixing hole 15 on the upper layer circuit board 16 and the fixing hole 7 on the middle layer circuit board 17 respectively;

the middle shaft hole of the nylon stud II 21 is aligned with the fixing hole 7 on the middle layer circuit board 17 and the fixing hole 4 on the bottom layer circuit board 18 respectively;

the nylon screw 19 downwards passes through the fixing hole 15 on the upper circuit board 16 from the upper part of the upper circuit board 16 and then is screwed into the nylon stud 20;

the nylon screw II 23 passes through the fixing holes 4, the nylon studs 21 and the fixing holes 7 on the middle layer circuit board 17 on the bottom layer circuit board 18 in turn from the bottom of the bottom layer circuit board 18 upwards and then is screwed into the nylon studs 20, so that the upper layer circuit board 16, the middle layer circuit board 17 and the bottom layer circuit board 18 are fixed together.

Fig. 13 and 14 are graphs showing simulation and test return loss results of the dual-linear polarized antenna feed array of embodiment 1 of the present invention, wherein: fig. 13 simulation (where port 1, port 3, port 5, port 7 are receiving ports, port 2, port 4, port 6, port 8 are transmitting ports); fig. 14 receive and transmit port measurements. Therefore, the echoes of the receiving port and the transmitting port are respectively smaller than-10 dB within the ranges of 12.25 GHz-12.75 GHz and 13.75 GHz-14.5 GHz, and good matching is achieved.

Fig. 15 and 16 are simulation and actual measurement array receiving directivity diagrams of the dual-linear polarized antenna feed source array of embodiment 1 of the present invention at 12.5GHz of the operating frequency point, wherein: FIG. 15 simulation results in azimuth plane 0℃and azimuth plane 90 °; fig. 16 shows the results of actual measurement in azimuth plane 0 ° and azimuth plane 90 °. It can be seen that when the antenna is operated at 12.5GHz, the gain of the antenna in the zenith direction is 15dB, and the side lobe is 10dB (simulation)/18 dB lower than the main lobe (actual measurement).

Fig. 17 and fig. 18 are simulation and actual measurement array emission directivity diagrams of the dual-linear polarized antenna feed source array of embodiment 1 of the present invention at an operating frequency point of 14.1GHz, wherein: FIG. 17 simulation results in azimuth plane 0℃and azimuth plane 90 °; fig. 18 shows the results of actual measurement in azimuth plane 0 ° and azimuth plane 90 °. It can be seen that when the antenna is operated at 14.1GHz, the gain of the antenna in the zenith direction is 15dB, and the side lobe is 11dB (simulation)/10 dB lower than the main lobe (actual measurement).

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.

Claims

1. A dual-polarized antenna comprises a main reflector (3), a feed source array (2), a subsidiary reflector (1) and a mounting frame; the feed source array (2) is arranged on a main reflecting surface (710) of the main reflecting piece (3) by the mounting frame, the auxiliary reflecting piece (1) is arranged above the feed source array (2), the auxiliary reflecting surface (75) of the auxiliary reflecting piece (1) is parallel to the feed source array (2), the center of the auxiliary reflecting surface (75) and the center of the feed source array (2) are positioned on the same straight line, and the feed source array (2) is positioned at the focus of the main reflecting surface (710); it is characterized in that the method comprises the steps of,

the mounting frame comprises a column (712), a slot (73), a plurality of first positioning parts (74), a plurality of second positioning parts (76) and a plurality of support rods (78); one end of the upright post (712) is vertically fixed at the center of the main reflecting surface (710), the slot (73) is fixed at the other end of the upright post (712) and positioned at the focus of the main reflecting surface (710), and the feed source array (2) is arranged on the slot (73); the first positioning parts (74) are welded on the secondary reflecting surface (75) and are circularly distributed by taking the center of the secondary reflecting surface (75) as the center of a circle; the second positioning parts (76) are welded on the bottom surface (77) of the slot (73) and are in annular layout by taking the center of the feed source array (2) as the center, the second positioning parts (76) are respectively in one-to-one correspondence with the first positioning parts (74), the second positioning parts (76) and the corresponding first positioning parts (74) are positioned on the same plane, and the plane is perpendicular to the secondary reflecting surface (75); one end of each supporting rod (78) is fixed on one of the first positioning parts (74), and the opposite other end of each supporting rod (78) is fixed on one of the second positioning parts (76); each supporting rod (78) is of a sheet-shaped structure which is bent for many times, and the two ends of each supporting rod (78) are arranged up and down oppositely and are parallel to each other;

the feed source array (2) comprises an upper layer circuit board (16), a middle layer circuit board (17) and a bottom layer circuit board (18) which are sequentially arranged from top to bottom; the upper layer circuit board (16), the middle layer circuit board (17) and the bottom layer circuit board (18) are fixed at intervals and are parallel to each other; the bottom circuit board (18) is a microstrip reflecting plate with a metal floor, and a plurality of transmitting antenna feed ports and receiving antenna feed ports are formed on the bottom circuit board; the middle layer circuit board (17) is of a microstrip antenna structure, the front and the back of the middle layer circuit board are divided into a plurality of areas by the latticed metal strip circuits (14), and the latticed metal strip circuits (14) on the front and the back are mutually conducted by metallized through holes; the upper circuit board (16) is a dielectric board; a bottom side of the bottom layer circuit board (18) is attached with a conductor;

the distance between the middle layer circuit board (17) and the bottom layer circuit board (18) is 0.1-0.3 lambda, the distance between the upper layer circuit board (16) and the middle layer circuit board (17) is 0.3-0.7 lambda, lambda is the free space wavelength corresponding to the working frequency; the front of each area on the middle layer circuit board (17) is respectively provided with a metal dipole serving as a receiving antenna (9), a receiving antenna feed pad (10) and a transmitting antenna feed pad (8), the back of each area is provided with a metal dipole serving as a transmitting antenna (13), the receiving antenna feed pad (10) is connected with the receiving antenna (9), the transmitting antenna feed pad (8) is connected with the transmitting antenna (13), and the receiving antennas (9) and the transmitting antennas (13) in the front and back corresponding areas are arranged in a 90-degree crossed mode.

2. The dual-polarized antenna of claim 1, wherein: the mounting frame also comprises a base (711), wherein the base (711) is fixed at the center of the main reflecting surface (710), and the upright posts (712) are vertically fixed on the base (711).

3. The dual-polarized antenna of claim 1, wherein: the base (711) is fixed at the center of the main reflecting surface (710) through a plurality of fasteners; the slot (73) and the upright post (712) are both cylindrical, and the diameter of the upright post (712) is smaller than the diameter of the slot (73).

4. The dual-polarized antenna of claim 1, wherein: one end of each supporting rod (78) is fixed with the first positioning part (74) and extends in parallel along the edge of the secondary reflecting surface (75), and after extending out of the secondary reflecting surface (75), the supporting rod is bent downwards and extends to the second positioning part (76), and then is bent and extends to the corresponding second positioning part (76) in parallel along the bottom surface (77).

5. The dual-polarized antenna of claim 1, wherein: one end of each supporting rod (78) is fixed on the first positioning part (74) and extends in parallel along the edge of the secondary reflecting surface (75), and after extending out of the secondary reflecting surface (75), the supporting rod is bent downwards and extends vertically, and then is bent towards the second positioning part (76) and extends, after extending to the second positioning part (76), the supporting rod is bent and extends to the corresponding second positioning part (76) in parallel along the bottom surface (77).

6. The dual-polarized antenna of claim 1, wherein: the mounting bracket further includes a plurality of fasteners, each support rod (78) being secured to a respective first location (74) by at least one fastener and to a respective second location (76) by at least one other fastener.

7. The dual-polarized antenna of claim 6, wherein: the support rods (78) are positioned on the same side of the corresponding first positioning part (74) and the corresponding second positioning part (76), and one side edge of the support rods (78) is adhered to the corresponding first positioning part (74) and the corresponding second positioning part (76).

8. The dual-polarized antenna of claim 1, wherein: the bottom layer circuit board (18) is provided with 4 feed holes (5) along the radial direction, two sides of the 4 radial feed holes (5) are also provided with 2 feed holes (5) respectively, 8 feed holes (5) are arranged in total, four feed holes are feed holes of the transmitting antenna, and four feed holes of the receiving antenna.

9. The dual-polarized antenna of claim 1, wherein: a plurality of nylon studs (20) are arranged between the upper circuit board (16) and the middle circuit board (17), the middle shaft holes of the nylon studs (20) are respectively aligned with the fixing holes (15) on the upper circuit board (16) and the fixing holes (7) on the middle circuit board (17), a plurality of nylon studs (21) are arranged between the middle circuit board (17) and the bottom circuit board (18), and the middle shaft holes of the nylon studs (21) are respectively aligned with the fixing holes (7) on the middle circuit board (17) and the fixing holes (4) on the bottom circuit board (18).

10. The dual-polarized antenna of claim 9, wherein: the nylon screw I (19) downwards passes through the fixing holes (15) on the upper circuit board (16) from the upper part of the upper circuit board (16) and then is screwed into the nylon stud I (20), the nylon screw II (23) upwards passes through the fixing holes (4) on the bottom circuit board (18), the nylon studs II (21) and the fixing holes (7) on the middle circuit board (17) from the bottom of the bottom circuit board (18) in sequence, and then is screwed into the nylon stud I (20), so that the upper circuit board (16), the middle circuit board (17) and the bottom circuit board (18) are fixed together.