阅读说明：本技术 一种基于多层矩形波导功分结构的cts天线 (CTS antenna based on multilayer rectangular waveguide power dividing structure ) 是由 吴锡东 雷国清 冀俊超 童利 周金芳 于 2021-04-06 设计创作，主要内容包括：本发明公开了一种基于多层矩形波导功分结构的CTS天线,包括矩形波导馈电网络,以及与所述矩形波导馈电网络的输出端口连接的CTS辐射结构,所述矩形波导馈电网络包括一个一分N的矩形波导水平功率分配网络,以及N个一分M的矩形波导垂直功率分配网络,所述N个矩形波导垂直功率分配网络通过矩形波导弯头分别与所述矩形波导水平功率分配网络的N个输出端口相连接；所述N个矩形波导垂直功率分配网络沿水平方向等间距平行排列,其所在平面与矩形波导水平功率分配网络所在平面正交。本发明具有低损耗、低副瓣、低剖面等特点,适用于移动卫星通信、高速数据传输等应用场合。(The invention discloses a CTS antenna based on a multilayer rectangular waveguide power distribution structure, which comprises a rectangular waveguide feed network and a CTS radiation structure connected with an output port of the rectangular waveguide feed network, wherein the rectangular waveguide feed network comprises a one-to-N rectangular waveguide horizontal power distribution network and N one-to-M rectangular waveguide vertical power distribution networks, and the N rectangular waveguide vertical power distribution networks are respectively connected with N output ports of the rectangular waveguide horizontal power distribution network through rectangular waveguide elbows; the N rectangular waveguide vertical power distribution networks are arranged in parallel at equal intervals along the horizontal direction, and the plane where the N rectangular waveguide vertical power distribution networks are located is orthogonal to the plane where the rectangular waveguide horizontal power distribution networks are located. The invention has the characteristics of low loss, low side lobe, low profile and the like, and is suitable for application occasions of mobile satellite communication, high-speed data transmission and the like.)

1. A CTS antenna based on a multilayer rectangular waveguide power distribution structure is characterized by comprising a rectangular waveguide feed network and a CTS radiation structure connected with an output port of the rectangular waveguide feed network, wherein the rectangular waveguide feed network comprises a one-to-N rectangular waveguide horizontal power distribution network and N one-to-M rectangular waveguide vertical power distribution networks, the N rectangular waveguide vertical power distribution networks are respectively connected with N output ports of the rectangular waveguide horizontal power distribution network through rectangular waveguide elbows, the N rectangular waveguide vertical power distribution networks are arranged in parallel at equal intervals in the horizontal direction, and the plane of each rectangular waveguide vertical power distribution network is orthogonal to the plane of the rectangular waveguide horizontal power distribution network.

2. A CTS antenna based on multilayer rectangular waveguide power splitting structure according to claim 1, wherein the rectangular waveguide horizontal power splitting network includes a plurality of rectangular waveguide H-plane power splitters, and the rectangular waveguide vertical power splitting network includes a plurality of rectangular waveguide E-plane power splitters; or the rectangular waveguide horizontal power distribution network comprises a plurality of rectangular waveguide E-plane power distributors, and the rectangular waveguide vertical power distribution network comprises a plurality of rectangular waveguide H-plane power distributors.

3. A CTS antenna based on multilayer rectangular waveguide power splitting structure as claimed in claim 2, wherein said one-to-N rectangular waveguide horizontal power splitting network includes several one-to-two rectangular waveguide equal and unequal power splitters for equally or unequally splitting energy in H-plane or E-plane, said power splitter branch waveguide plane being parallel to the plane of TE10 mode magnetic or electric field.

4. A CTS antenna based on multilayer rectangular waveguide power splitting structure as claimed in claim 2, wherein said one-to-M rectangular waveguide vertical power splitting network includes several one-to-two rectangular waveguide equal and unequal power splitters for equally or unequally splitting energy in E-plane or H-plane, said power splitter branch waveguide plane being parallel to the plane of TE10 mode electric or magnetic field.

5. A CTS antenna based on multilayer rectangular waveguide power splitting structure as claimed in claim 2, wherein the rectangular waveguide H-plane power splitter includes an H-plane T-junction, two rectangular waveguide bends, several steps and two output arms; the rectangular waveguide E-surface power divider comprises an E-surface T-shaped junction, two rectangular waveguide elbows, a plurality of steps and two output arms; the E-surface T-shaped junction or the H-surface T-shaped junction is formed by connecting an input arm and two horizontal arms, and the horizontal arms are connected with the output arm through rectangular waveguide elbows.

6. A CTS antenna based on multilayer rectangular waveguide power dividing structure as claimed in claim 1, wherein the rectangular waveguide elbow is composed of rectangular waveguides perpendicular to each other, and wherein a matching structure is provided at the waveguide junction.

7. A CTS antenna based on multilayer rectangular waveguide power dividing structure according to claim 2, wherein when the horizontal power dividing network includes a plurality of rectangular waveguide H-plane power dividers and the vertical power dividing network includes a plurality of rectangular waveguide E-plane power dividers, the CTS radiating structure includes a plurality of radiating elements, the radiating elements are tangential through slot structures, and are composed of steps or horns with single-stage or multi-stage openings gradually increasing, and the tangential direction is the direction in which the plurality of rectangular waveguide vertical power dividing networks are arranged. The single CTS radiation unit is connected with the same output ports of the N vertical power distribution networks, the arrangement distance of the same output ports of the N vertical power distribution networks is smaller than lambda, wherein lambda is the free space wavelength of the highest working frequency, the arrangement direction of the M CTS radiation units is orthogonal to the tangential direction, and the arrangement distance is smaller than lambda.

8. A CTS antenna based on multilayer rectangular waveguide power dividing structure as claimed in claim 2, wherein when the horizontal power dividing network includes a plurality of rectangular waveguide E-plane power dividers and the vertical power dividing network includes a plurality of rectangular waveguide H-plane power dividers, the CTS radiating structure includes a plurality of radiating elements, the radiating elements are transverse through slot structures, and are composed of steps or horns with single-stage or multi-stage openings gradually increasing, and the transverse direction is perpendicular to the arrangement direction of the plurality of rectangular waveguide vertical power dividing networks. The single CTS radiation unit is connected with all output ports of the single vertical power distribution network, the arrangement distance of the same output ports of the N vertical power distribution networks is smaller than lambda, wherein lambda is the free space wavelength of the highest working frequency, the arrangement direction of the N CTS radiation units is orthogonal to the transverse direction, and the arrangement distance is smaller than lambda.

9. An antenna arrangement comprising a CTS antenna as claimed in any one of claims 1 to 8.

10. A terminal device, characterized in that it comprises an antenna arrangement according to claim 9.

Technical Field

The invention relates to the technical field of antenna communication, in particular to a CTS antenna and an antenna device based on a multilayer rectangular waveguide power division structure.

Background

There is an increasing demand for wireless channels to transmit data at very high data rates, particularly in the field of mobile satellite communications. However, particularly in the aeronautical field, suitable antennas capable of meeting the conditions required for mobile use, such as in particular transceive-integrated and low-profile antennas, are lacking. For directional wireless data communication with satellites (e.g., in the Ku or Ka band), there are also extremely high requirements on the side lobe performance of the antenna, since interference between adjacent satellites must be reliably placed.

All regulatory requirements are intended to ensure that no interference is generated between adjacent satellites during directional transmission or reception operations of the mobile satellite antenna, according to the regulatory requirements of the satellite communication antenna. For this purpose, the maximum output main lobe width and side lobe level are usually defined based on the separation angle from the target satellite, and during the transmitting operation of the antenna system the value for a particular side lobe level must not be exceeded, and during the receiving operation of the antenna system the lower side lobe level may also reduce the interference of the ambient signal. This results in strict requirements on the antenna characteristics according to the angle. As the separation angle of the target satellite decreases, the antenna main lobe width needs to decrease, which requires the output phase configuration and amplitude configuration of the antenna to achieve. Therefore, a parabolic antenna having these characteristics is generally used. However, for most mobile applications, particularly for aircraft, a paraboloid has poor utility because of its large size. For example, in the case of commercial aircraft, the antenna is mounted to the fuselage and therefore must have a minimum profile height due to additional air resistance.

Due to the increasing demand for high transmission rates and highly reliable transmissions in communication systems, the CTS antenna is becoming a candidate antenna for advanced antenna systems as a flat panel antenna with good performance and manufacturing stability. Therefore, a series of studies have been conducted internationally on CTS antennas, which are waveguide slot antennas first proposed by William w.milory of the american leishment company in the nineties of the twentieth century, and which caused strong reverberation in the academic world (Milroy, w.w., "Continuous Transition Stub (CTS) element devices and methods of makingg same," U.S. patent 5,266,961, aug.29, 1991). The traditional CTS antenna is composed of a plurality of parallel plate waveguides with tangential slits at the openings, any longitudinal current component generated by the parallel plate waveguides excited by plane waves can be cut off by the transverse slits, the radiation unit and the parallel plate waveguides form a simple T-shaped structure, the structure is a non-resonant structure, and the CTS antenna has the characteristics of wide frequency band, low cross polarization and easiness in processing.

In practical application, the operating bandwidth of the radiating element is relatively wide, but the overall bandwidth of the antenna is limited by a series feeding mode and a port switching network. In order to increase the overall bandwidth of the antenna and achieve beam orientation, the CTS antenna (etorre, m., f.follia Manzillo, m.caseetti, r.sauleau, l.le Coq, and n.cap, "connecting transition stub for Ka-base applications," IEEE trans. antennas pro. No. vol.63, No.9, 4798-. Mauro Ettore et al describes a parallel-feed CTS antenna with 16 array elements of all metals, the antenna works in Ka wave band, the radiation unit is excited by quasi-TEM signals with equal amplitude and same phase generated by a plurality of equal power division waveguide T-shaped junctions, and the experimental result proves that the antenna is a CTS antenna array with high gain and low profile.

However, in the conventional CTS panel antenna, the equal power dividers are cascaded to form a feed network, and the antenna radiation units are fed with equal amplitude and in phase, so that the antenna efficiency is high, but the first minor lobe level cannot meet the requirement of guard-pass. This also directly results in that the panel antenna is difficult to access the network in the satellite communication system and the utilization rate is not high. In view of the above reasons, analyzing the conventional CTS panel antenna, the radiation intensity of the antenna radiation unit may be weighted, and the control of the side lobe level may be implemented by using a cone-shaped distribution.

Disclosure of Invention

The invention mainly aims to overcome the defects of the prior art and provides a CTS antenna and an antenna device based on a multilayer rectangular waveguide power division structure, which have the characteristics of low profile, low loss, low side lobe and the like.

In order to achieve the purpose, the invention adopts the following technical scheme: a CTS antenna based on a multilayer rectangular waveguide power distribution structure comprises a rectangular waveguide feed network and a CTS radiation structure connected with an output port of the rectangular waveguide feed network, wherein the rectangular waveguide feed network comprises a one-to-N rectangular waveguide horizontal power distribution network and N one-to-M rectangular waveguide vertical power distribution networks, the N rectangular waveguide vertical power distribution networks are respectively connected with N output ports of the rectangular waveguide horizontal power distribution network through rectangular waveguide elbows, the N rectangular waveguide vertical power distribution networks are arranged in parallel at equal intervals in the horizontal direction, and the plane of each rectangular waveguide vertical power distribution network is orthogonal to the plane of the rectangular waveguide horizontal power distribution network.

Further, the rectangular waveguide horizontal power distribution network comprises a plurality of rectangular waveguide H-plane power distributors, and the rectangular waveguide vertical power distribution network comprises a plurality of rectangular waveguide E-plane power distributors; or the rectangular waveguide horizontal power distribution network comprises a plurality of rectangular waveguide E-plane power distributors, and the rectangular waveguide vertical power distribution network comprises a plurality of rectangular waveguide H-plane power distributors.

Further, the one-to-N rectangular waveguide horizontal power distribution network comprises a plurality of one-to-two rectangular waveguide equal-dividing and unequal-dividing power distributors, and is used for equally or unequally distributing energy in an H plane (when the vertical power distribution network comprises a plurality of rectangular waveguide E-plane power distributors) or an E plane (when the vertical power distribution network comprises a plurality of rectangular waveguide H-plane power distributors), and the branch waveguide planes of the power distributors are parallel to the plane where the TE10 mode magnetic field or electric field is located.

Further, the one-to-M rectangular waveguide vertical power distribution network comprises a plurality of one-to-two rectangular waveguide equal-division and unequal-division power distributors, and is used for equally or unequally distributing energy in an E plane (when the horizontal power distribution network comprises a plurality of rectangular waveguide H-plane power distributors) or an H plane (when the horizontal power distribution network comprises a plurality of rectangular waveguide E-plane power distributors), and the branch waveguide planes of the power distributors are parallel to a plane where a TE10 mode electric field or magnetic field is located.

Further, the rectangular waveguide H-surface power divider comprises an H-surface T-shaped junction, two rectangular waveguide elbows, a plurality of steps and two output arms; the rectangular waveguide E-surface power divider comprises an E-surface T-shaped junction, two rectangular waveguide elbows, a plurality of steps and two output arms; the E-surface T-shaped junction or the H-surface T-shaped junction is formed by connecting an input arm and two horizontal arms, and the horizontal arms are connected with the output arm through rectangular waveguide elbows.

Furthermore, the rectangular waveguide elbow is composed of rectangular waveguides which are perpendicular to each other, wherein a matching structure is arranged at the joint of the waveguides.

Further, when the horizontal power distribution network comprises a plurality of rectangular waveguide H-surface power distributors and the vertical power distribution network comprises a plurality of rectangular waveguide E-surface power distributors, the CTS radiation structure comprises a plurality of radiation units, the radiation units are tangential groove structures which are communicated in a tangential manner and are formed by steps or loudspeakers with single-stage or multi-stage openings which are gradually increased, and the tangential direction is the arrangement direction of the rectangular waveguide vertical power distribution networks. The single CTS radiation unit is connected with the same output ports of the N vertical power distribution networks, the arrangement distance of the same output ports of the N vertical power distribution networks is smaller than lambda, wherein lambda is the free space wavelength of the highest working frequency, the arrangement direction of the M CTS radiation units is orthogonal to the tangential direction, and the arrangement distance is smaller than lambda.

Further, when the horizontal power distribution network comprises a plurality of rectangular waveguide E-plane power distributors and the vertical power distribution network comprises a plurality of rectangular waveguide H-plane power distributors, the CTS radiating structure comprises a plurality of radiating units, the radiating units are transverse through groove structures, and are formed by steps or horns with single-stage or multi-stage openings gradually increasing, and the transverse direction is perpendicular to the arrangement direction of the plurality of rectangular waveguide vertical power distribution networks. The single CTS radiation unit is connected with all output ports of the single vertical power distribution network, the arrangement distance of the same output ports of the N vertical power distribution networks is smaller than lambda, wherein lambda is the free space wavelength of the highest working frequency, the arrangement direction of the N CTS radiation units is orthogonal to the transverse direction, and the arrangement distance is smaller than lambda.

The invention also provides an antenna device comprising the CTS antenna.

The invention also provides terminal equipment comprising the antenna device.

Compared with the prior art, the invention has the following beneficial effects: firstly, the antenna of the invention adopts rectangular waveguide feed, compared with a strip, a microstrip line and a coplanar waveguide, the loss of the whole system caused by signal transmission is reduced, and the system efficiency is improved, which is very important under the millimeter wave frequency band. Secondly, the antenna adopts a novel tree-shaped feed network structure, the structure has a lower section compared with the traditional feed structure, so the weight is lighter, and the network can output excitation signals with unequal amplitude and in-phase distribution, so that the antenna output gain has lower side lobes under the condition of meeting the target requirement; in terms of manufacturing, since the cross-section of the antenna feed is constant in one dimension, cheaper, larger-volume manufacturing techniques, such as injection molding and extrusion processes, can be used in addition to milling.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 schematically illustrates a front view of a CTS antenna in accordance with an exemplary disclosed embodiment of the invention;

FIG. 2 is a schematic representation of a three-dimensional structure of a CTS antenna in accordance with an exemplary embodiment of the present disclosure;

fig. 3 schematically shows a three-dimensional structure diagram of a rectangular waveguide E-plane unequal power divider of a CTS antenna in an embodiment of the present disclosure;

fig. 4 schematically shows a front view of a rectangular waveguide E-plane unequal power divider of a CTS antenna in accordance with an embodiment of the present disclosure;

fig. 5 schematically shows a three-dimensional structure diagram of a CTS antenna rectangular waveguide H-plane equipartition power divider according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram showing a front view of a rectangular waveguide H-plane equal-division power divider of a CTS antenna in an embodiment of the present disclosure;

fig. 7 schematically shows a three-dimensional structure diagram of a final stage power divider and a radiation unit of a CTS antenna according to an embodiment of the present disclosure;

fig. 8 schematically illustrates a front view of a final stage power divider and a radiating element of a CTS antenna in accordance with an exemplary embodiment of the present disclosure;

fig. 9 schematically shows a three-dimensional structure of a rectangular waveguide bend of a CTS antenna in accordance with an embodiment of the present disclosure.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that, if directional indications (such as up, down, left, right, front, back, horizontal, vertical, etc.) are involved in the embodiment of the present invention, the directional indications are only used for explaining the relative positional relationship, motion conditions, etc. of the components in a certain posture (as shown in the drawing), and if the certain posture is changed, the directional indications are changed accordingly.

In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

As shown in fig. 1 to 9, a CTS antenna based on a multilayer rectangular waveguide power division structure provided by an embodiment of the present invention includes a rectangular waveguide feed network, and a CTS radiating unit 3 connected to an output port of the rectangular waveguide feed network; the rectangular waveguide feed network comprises a one-to-N rectangular waveguide horizontal power distribution network 1 and N one-to-M rectangular waveguide vertical power distribution networks 2, wherein the N rectangular waveguide vertical power distribution networks 2 are respectively connected with N output ports of the rectangular waveguide horizontal power distribution network 1 through rectangular waveguide elbows 4; the N rectangular waveguide vertical power distribution networks 2 are arranged in parallel at equal intervals, and the plane where the N rectangular waveguide vertical power distribution networks are arranged is orthogonal to the plane where the rectangular waveguide horizontal power distribution network 1 is arranged.

In one embodiment, the rectangular waveguide horizontal power distribution network 1 includes a plurality of rectangular waveguide H-plane equal-division power dividers 6 and a plurality of rectangular waveguide H-plane unequal-division power dividers 7.

Further, the rectangular waveguide H-plane equipartition power divider 6 and the rectangular waveguide H-plane equipartition power divider 7 are two-way power dividers, each of which includes an H-plane T-junction, two rectangular waveguide elbows 5, a plurality of steps, and two output arms 13, the H-plane T-junction is formed by connecting an input arm 11 and two horizontal arms 12, the horizontal arm 12 is connected with the output arms 13 through the rectangular waveguide elbows 5, the waveguide height of the horizontal arm 12 is equal to the waveguide height of the output arms, and is as small as possible in consideration of the conductor loss.

Further, the rectangular waveguide vertical power distribution network 2 includes a plurality of rectangular waveguide E-plane equal-division power dividers 8 and rectangular waveguide E-plane unequal-division power dividers 9.

Further, the rectangular waveguide E-plane equipartition power divider 8 and the rectangular waveguide E-plane unequal power divider 9 are both two-way power dividers, wherein each power divider is composed of an E-plane T-junction, two rectangular waveguide elbows 10, a plurality of steps, and two output arms 16; the E-plane T-shaped junction is formed by connecting an input arm 14 and two horizontal arms 15, the horizontal arms 15 are connected with an output arm 16 through rectangular waveguide elbows 10, and the waveguide height of the horizontal arms 15 is equal to that of the output arm and is as small as possible under the condition of considering conductor loss. When all the radiating elements 3 are excited in a defined manner, mutual coupling between the elements of the array antenna occurs and energy is radiated.

Further, the structures of the rectangular waveguide E-plane equipartition power divider 8 and the rectangular waveguide E-plane unequal power divider 9 are as follows: a plurality of first steps 18 are arranged on the junction of the horizontal arm and the input arm in the vertical direction of the lower surface of the horizontal arm and used for impedance matching; a second step 17 is arranged at the junction of the horizontal arm and the input arm in the central axis direction of the upper surface of the horizontal arm and is used for isolating the output port; the rectangular waveguide bend 10 includes a third step 20 for impedance matching. The first step 18, the second step 17 and the third step 20 are all rectangular steps. In this embodiment, the first step 18 is a two-step stepped structure, and the step height thereof gradually decreases from the horizontal arm to the two ends.

Further, the rectangular waveguide E-plane unequal power divider 9 has a phase compensation structure and a power division ratio adjustment structure; the phase compensation structure specifically comprises: at the junction of the horizontal arm at one side and the output arm at one side, the upper surface of the horizontal arm is provided with a fourth step 19 (rectangular step) towards the outer side of the waveguide for phase compensation; the power division ratio adjusting structure specifically comprises: the adjustment of the output port power ratio is achieved by adjusting the height difference of the two highest steps 21 in the first step 18. In this embodiment, the height difference between the two highest steps 21 in the first steps 18 is different, and the height difference is used for adjusting the power dividing ratio of the output end by changing the input impedance of the horizontal arm branch; the adjusting range of the power ratio is 1-3, the height of the highest step 21 in the first steps 18 is not more than 0.75h, and h is the waveguide height of the horizontal arm. In addition, the waveguide wavelength of the horizontal arm rectangular waveguide can be changed by changing the step height and width of the fourth step 19, which is used to compensate for the phase difference caused by the highest step height difference of the first step 18, so that the phases of the electromagnetic waves of the output arms are made uniform. Wherein, the phase takes 0 degree as the center, and plus or minus 20 degrees is adjustable.

Further, the rectangular waveguide H-plane equal-division power divider 6, the rectangular waveguide H-plane equal-division power divider 7, the rectangular waveguide E-plane equal-division power divider 8, and the rectangular waveguide E-plane equal-division power divider 9 change the impedance value of the port by changing the step height. The junction of the horizontal arm and the input arm is provided with a plurality of rectangular steps, and the multistage steps are used as an impedance transformer of the horizontal arm to match a T-shaped junction and a waveguide elbow.

Further, the output port of the rectangular waveguide vertical power distribution network 2 is connected to the N × M radiation ports 22, and the radiation ports 22 are extended from the H plane and connected to obtain M radiation units 3.

Further, energy is fed through the rectangular waveguide input port, power dividers at each stage of the rectangular waveguide horizontal power distribution network 1 are uniformly or non-uniformly distributed, then the power dividers are connected and input into the rectangular waveguide vertical power distribution network 2 through the rectangular waveguide elbows 4, power dividers at each stage of the rectangular waveguide vertical power distribution network 2 are uniformly or non-uniformly distributed, finally the phase reaching the final stage output port is the same, and the amplitude is in taylor distribution with two flattened ends along the central axis.

Further, the radiation unit 3 is implemented by a waveguide impedance transformer or a waveguide slot; the waveguide impedance converter is realized by a fan-shaped horn structure (including an asymptote structure or a linear structure) or a step with gradually increased multi-stage openings. In the direction of the front surface, an appropriate cell pitch can be selected to prevent the occurrence of grating lobes.

Further, the feed network must be non-dispersive, i.e. the nonlinear phase and amplitude changes with frequency are negligible.

Further, the rectangular waveguide can be made of a metal material, such as 6061T6 aluminum, or a low-loss microwave dielectric material with a metal-plated surface, and the dielectric filling mode can be partial filling or whole filling. The processing mode can be milling, injection molding and extrusion molding. In order to maximize the antenna aperture efficiency, the width of the portion between two adjacent radiating elements 3 should be made as thin as possible, set to the minimum size that can be achieved by nc milling, injection molding, extrusion molding, and it is necessary to assemble with a specific structure (such as an end plate) and to ensure the assembly accuracy.

In one embodiment of the present invention, as shown in fig. 1 and 2, an example of a low sidelobe shunt-fed CTS antenna is implemented in accordance with the principles of the present invention. The antenna example uses rectangular metal waveguides as transmission lines, the overall structure is divided into an eight-in-eight rectangular waveguide horizontal power distribution network, eight one-in-sixteen rectangular waveguide vertical power distribution networks vertically connected with the eight-in-eight rectangular waveguide horizontal power distribution network and a CTS radiation array surface with sixteen radiation units, wherein the rectangular waveguide horizontal power distribution network is an eight-way waveguide power divider symmetrical along a central axis, and consists of a three-level two-way rectangular waveguide H-plane equal-division power divider 6 and a rectangular waveguide H-plane unequal-division power divider 7, the function is to distribute energy to the next level uniformly or non-uniformly, and the design of each rectangular waveguide power divider adopts the design method described in the invention. The rectangular waveguide vertical power distribution network is a sixteen-way waveguide power divider symmetrical along a central axis, and consists of a four-level two-way rectangular waveguide E-surface equal power divider 8 and a rectangular waveguide E-surface unequal power divider 9, and is used for distributing energy to the next level according to a certain proportion, and the design of each rectangular waveguide power divider adopts the design method described in the invention. The radiation front is composed of sixteen radiation units 3 which are formed by connecting 16-8 radiation ports in an extending mode in the direction of an H face, and the radiation front has the function of matching waveguide and air impedance and radiating energy to free space. When the antenna works, radio frequency energy is fed in through the rectangular waveguide input port, the energy is uniformly or non-uniformly distributed between the two horizontal arms of each stage of power divider, the energy reaching the output port of the last stage of the tree-shaped feed network is identical in phase, and the amplitude is in Taylor distribution with two flattened ends along the central axis.

As shown in fig. 3 and 4, the rectangular waveguide E-plane power divider is composed of an E-plane T-junction, two rectangular waveguide bends 10, a plurality of steps, and two output arms 16; the E-plane T-shaped junction is formed by connecting an input arm 14 and two horizontal arms 15, and the horizontal arms 15 are connected with an output arm 16 through rectangular waveguide elbows 10. Two output arms 16 are arranged parallel to the input arm 14 and a horizontal arm 15 is arranged in the middle for connecting the input and output ports. Because the relation between the waveguide height of the first step 18 of the horizontal arm and the waveguide impedance is simple, the design method for controlling the power division ratio of the power divider by controlling the waveguide height of the first step 18 is simple and easy to implement, and the larger the height difference between the left end and the right end is, the larger the output power division ratio of the two output ports is. A plurality of first steps 18 are arranged on the junction of the horizontal arm and the input arm in the vertical direction of the lower surface of the horizontal arm and used for impedance matching; a second step 17 is arranged at the junction of the horizontal arm and the input arm in the central axis direction of the upper surface of the horizontal arm and is used for isolating the output port; the rectangular waveguide bend 10 includes a third step 20 for impedance matching, and the size of the third step can be selected to cut off unwanted higher order modes. The first step 18, the second step 17 and the third step 20 are all rectangular steps.

As shown in fig. 5 and 6, the H-plane equipartition power divider includes an H-plane T-junction, two rectangular waveguide bends 5, a plurality of steps, and two output arms 13, the H-plane T-junction is formed by connecting an input arm 11 and two horizontal arms 12, the horizontal arms 12 are connected to the output arms 13 through the rectangular waveguide bends 5, and the waveguide height of the horizontal arms 12 is equal to that of the output arms, and is as small as possible in consideration of conductor loss.

Fig. 7 and 8 are schematic diagrams of the radiation unit 3 and the final stage power divider, in which the input arm 14 and the output arm 16 are disposed in parallel, and the impedance transformer is a fan-shaped horn structure 23 for radiating energy. And the impedance matching is realized by the combination of the impedance converter and the final-stage power divider.

Fig. 9 is a schematic diagram of a rectangular waveguide elbow in which the rectangular third step 20 is an impedance matching structure.

The CTS antenna of the present invention may be applied to a corresponding antenna apparatus. Furthermore, the antenna device can also be installed on various terminal devices, such as a communication base station, a vehicle-mounted antenna terminal, a satellite terminal and the like.

The above is a specific implementation manner of the embodiment of the present invention, and those skilled in the art can manufacture the low sidelobe and feed CTS antenna by applying the method disclosed in the present invention and some alternative ways without creative efforts. The antenna has the characteristics of low profile, high efficiency and the like, and is suitable for being used as a directional antenna. However, the embodiments of the present invention are not limited to the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and they are included in the scope of the present invention.