CN111929647A

CN111929647A - Ka frequency band multi-horn single pulse feed source network

Info

Publication number: CN111929647A
Application number: CN202010895228.7A
Authority: CN
Inventors: 阮云国; 邓智勇; 周建寨; 王垒; 苏丽; 李毅伟; 李盾; 孙焕金; 孙立杰; 张博; 张根会
Original assignee: CETC 54 Research Institute
Current assignee: CETC 54 Research Institute
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2020-11-13

Abstract

The invention discloses a Ka frequency band multi-horn single-pulse feed source network, and belongs to the technical field of feed source networks. The microwave multi-port differential feed comprises a feed source and a microwave network, and 4 ports are simultaneously output, namely 2 ports of a differential channel and 2 ports of a channel. The system controls the irradiation of the sum and difference primary directional diagrams of the feed network through the medium loading and 9-horn combined feed source technology, and realizes the characteristics of low side lobe, low cross polarization, low difference zero depth and high difference slope of the antenna. The waveguide separator is utilized to skillfully realize the spatial separation of 5 paths of signals, and conditions are provided for the synthesis of difference signals. And the application of the dielectric air waveguide transition and the orthogonal mode coupler also realizes the full polarization characteristic of the feed source. The invention can realize that one antenna outputs 4 wave beams simultaneously, greatly improves the utilization efficiency of the antenna, has the characteristics of compact structure and convenient installation and use, and is an important improvement on the prior art.

Description

Ka frequency band multi-horn single pulse feed source network

Technical Field

The invention relates to the technical field of feed source networks, in particular to a Ka frequency band multi-horn single-pulse feed source network.

Background

In recent years, low-frequency radar applications tend to be saturated, and research on high-frequency radar is gradually started. The high-frequency band radar has important application prospect in the fields of biology and meteorology, so that the high-frequency band radar is favored by researchers.

An important component of radar is the radar antenna, and the core of the radar antenna is the feed network. At present, the low-frequency band feed network technology for radar in China is mature, while the feed network technology of millimeter wave bands is relatively few, so that the related research is concerned at home and abroad.

The traditional five-horn single-pulse feed source has the advantages that the upper horn and the lower horn form a pitching difference, the left horn and the right horn form a azimuth difference, the middle is a sum channel, and due to the contradiction of the horn spacing, the feed source generally has low difference gain and small difference slope, and cannot meet the requirement of high-precision tracking.

Disclosure of Invention

In view of this, the present invention provides a Ka band multi-horn monopulse feed network, which is easy to process and has good electrical performance, and can implement simultaneous differential signal output for one antenna, thereby greatly improving the utilization efficiency of the antenna, and having the advantages of full polarization and high efficiency.

In order to achieve the purpose, the invention provides the technical scheme that:

a Ka frequency band multi-horn single pulse feed source network comprises a multi-horn feed source system 1 and a microwave network; the microwave network comprises a waveguide splitter 2, a first magic T, a second magic T6 and an orthomode coupler 9; the front end of the waveguide separator 2 is provided with an input end for connecting the multi-horn feed source system 1, the rear end is provided with a medium square waveguide, and four side surfaces are respectively provided with a rectangular waveguide output end; the rectangular waveguide output ends of the left and right side surfaces of the waveguide separator 2 are respectively connected with a first rectangular transition waveguide, two H-surface

curved waveguides

7 and 8 are sequentially connected behind each first rectangular transition waveguide, and the two H-surface curved waveguides 8 at the tail end are connected with a first magic T; the rectangular waveguide output ends of the upper side surface and the lower side surface of the waveguide separator 2 are respectively connected with a second rectangular transition waveguide 3, two

E-surface bent waveguides

4 and 5 are sequentially connected behind each second rectangular transition waveguide 3, and the two E-surface bent waveguides 5 at the tail end are connected with a second magic T6; the medium square waveguide of the waveguide separator 2 is connected with the orthogonal mode coupler 9; the orthomode coupler 9 outputs two Ka sum channels, and the first magic T and the second magic T each output one Ka difference channel.

Further, the multi-horn feed system 1 is a 9-horn combined feed system.

Furthermore, four loudspeakers in the 9-loudspeaker combined feed source system are used for improving signals and do not output signals, and the other five loudspeakers respectively have an output end; the input end of the waveguide separator 2 is five square waveguide input ends corresponding to five output ends of the 9-horn combined feed source system, the five square waveguide input ends are distributed in a cross shape, wherein the four peripheral square waveguide input ends change output signals of the four horns into rectangular waveguides through a square-moment natural transition structure and output the rectangular waveguides to the rectangular waveguide output end on the side face of the waveguide separator 2 through a bent waveguide impedance matching structure, and the middle square waveguide input end outputs the output signal of another horn to the dielectric square waveguide at the rear end of the waveguide separator 2.

Further, the dielectric square waveguide is a square transition waveguide with a large rear end and a small front end, and the front end of the dielectric square waveguide is inserted into the air waveguide of the waveguide separator 2 to form the air dielectric transition waveguide.

From the above, it can be seen that the beneficial effects of the present invention are:

1. in the invention, the Ka frequency band 9 horn feed-forward combined feed source provides ideal irradiation level and irradiation phase requirements. The antenna can have side lobe levels below 20dB and a relatively good differential slope.

2. The feed source network of the invention has 4 output ports, which are 2 ports of Ka difference channel and 2 ports of Ka sum channel. And the Ka difference channel azimuth difference and the Ka difference channel pitch difference are output simultaneously. The invention can realize that one antenna can simultaneously output 4 wave beams, namely azimuth difference wave beams, elevation difference wave beams, horizontal wave beams, vertical wave beams and wave beams, thereby greatly improving the utilization efficiency of the antenna.

3. The invention reduces the array pitch of the horn and effectively improves the radiation characteristic of the feed source through medium loading.

4. The application of the waveguide separator in the invention ensures that 5 paths of output waveguides have enough space for difference signal synthesis.

5. The matching performance of the feed source network is better improved through the tip-shaped medium transition structure.

In a word, the invention has the characteristics of good electrical performance, multiple functions and simple structure, and is a great progress compared with the prior art.

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 invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

Fig. 1 is a schematic diagram of an overall structure of a Ka-band multi-horn single-pulse feed network in the embodiment of the invention.

Fig. 2 is a schematic diagram of the waveguide separator of fig. 1, with an input end view on the left and an output end view on the right.

Fig. 3 is a perspective sectional view of fig. 2.

Fig. 4 is a cross-sectional view of fig. 2.

Fig. 5 is a schematic structural diagram of the 9-horn combined feed source in fig. 1.

Fig. 6 and 7 are schematic structural views of the air-medium transition waveguide in the waveguide separator.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention are further described in detail below with reference to the accompanying drawings in combination with the specific embodiments.

As shown in figures 1-7, a Ka frequency band multi-horn monopulse feed network comprises a 9-horn combined feed 1 and a waveguide separator 2, the waveguide separator 2 has five input ends at the front end, four Ka frequency band rectangular waveguide output ends at four side walls and a medium square waveguide output end at the rear end, the input end of the waveguide separator 2 is connected with the 9-horn combined feed 1, the rectangular waveguide output ends in the horizontal direction of the waveguide separator 2 are connected with a rectangular transition waveguide 7, each rectangular transition waveguide 7 is connected with an H-plane curved waveguide 8, two H-plane curved waveguides 8 are connected with a first magic T, the rectangular waveguide output ends in the vertical direction of the waveguide separator 2 are connected with a rectangular transition waveguide 3, each rectangular transition waveguide 3 is connected with an E-plane curved waveguide 4, each E-plane curved waveguide 4 is connected with an E-plane curved waveguide 5, the two E-surface curved waveguides 5 are connected with a second magic T6, air medium transition waveguides are arranged at output ports of the square waveguides of the waveguide separator 2, and output ports of the medium transition waveguides are connected with an orthomode coupler 9.

The 9-horn combined feed source is 9 special-shaped square horn combined feed sources, and the feed source is composed of 9 medium cones, 9 special-shaped square waveguide sections and 4 medium air transitions. One horn located in the middle provides a sum signal, and four horns close to the middle horn provide a potential difference signal and a pitch difference signal. The four outermost horns do not output signals, and only play a role in improving radiation characteristics.

The input end of the waveguide separator 2 is five square waveguide input ends corresponding to five output ends of the 9-horn combined feed source system, and the five square waveguide input ends are distributed in a cross shape, wherein the four peripheral square waveguide input ends change output signals of the four horns into rectangular waveguides through a square moment natural transition structure and output the rectangular waveguides to the rectangular waveguide output end on the side face of the waveguide separator 2 through a bent waveguide impedance matching structure, and the middle square waveguide input end outputs the output signal of another horn to the dielectric square waveguide at the rear end of the waveguide separator 2.

The waveguide separator is isolated by a 5-path signal structure output by a feed source, the input of the waveguide separator is 5 square waveguide ports, the output of the waveguide separator is four rectangular waveguide ports and one square waveguide port, wherein the two parallel ports respectively form a azimuth difference signal and a pitch difference signal after passing through a moment transition, a bent waveguide and a magic T. The square waveguide output port of the waveguide separator forms the horizontal and vertical polarization output of the sum signal through an air dielectric waveguide transition, an orthogonal mode coupler and a feeder waveguide.

In the air dielectric transition waveguide, the low standing wave conversion between the dielectric waveguide and the air waveguide is realized through the tip-shaped dielectric transition conversion. The structure is shown in fig. 6 and 7, and a square transition dielectric waveguide is reversely arranged between the air waveguide and the dielectric waveguide, so that the low standing wave conversion of the two waveguides can be realized.

The multi-horn antenna realizes amplitude phase irradiation, and can ensure low loss, high efficiency and beam consistency of the antenna. Signals received by the feed source horn enter the waveguide separator, and each two paths of rectangular waveguide output signals are synthesized into azimuth and pitch difference signals through the magic T. An air medium transition waveguide 10 is arranged at the output end of the waveguide separator and is connected with an orthogonal mode coupler 9, so that the complete polarization output of the sum channel signal is formed.

In addition, after passing through the waveguide separator, the Ka frequency band signal can be output simultaneously through air medium transition conversion, a circular polarizer and an orthogonal film coupler.

In a word, the invention controls the irradiation of the sum and difference primary directional diagram of the feed network through the medium loading and 9-horn combined feed source technology, and realizes the characteristics of low side lobe, low cross polarization, low difference zero depth and high difference slope of the antenna. In addition, the waveguide separator is utilized to skillfully realize the spatial separation of 5 paths of signals, and conditions are provided for the synthesis of difference signals. The invention also forms the complete polarization output of the sum channel signal through the medium air waveguide transition and the broadband orthogonal mode coupler.

Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, is limited to these examples; within the idea of the invention, also technical features in the above embodiments or in different embodiments may be combined, the order of the steps may be adjusted, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity. Any omissions, modifications, substitutions, improvements and the like in the foregoing embodiments are intended to be included within the scope of the present invention within the spirit and principle of the present invention.

Claims

1. A Ka frequency band multi-horn single pulse feed source network comprises a multi-horn feed source system (1) and a microwave network; the microwave network is characterized by comprising a waveguide separator (2), a first magic T, a second magic T (6) and an orthogonal mode coupler (9); the front end of the waveguide separator (2) is provided with an input end used for being connected with the multi-horn feed source system (1), the rear end of the waveguide separator is provided with a medium square waveguide, and four side surfaces of the waveguide separator are respectively provided with a rectangular waveguide output end; the rectangular waveguide output ends of the left side surface and the right side surface of the waveguide separator (2) are respectively connected with a first rectangular transition waveguide, two H-surface bent waveguides (7 and 8) are sequentially connected behind each first rectangular transition waveguide, and the two H-surface bent waveguides (8) at the tail end are connected with a first magic T; the rectangular waveguide output ends of the upper side surface and the lower side surface of the waveguide separator (2) are respectively connected with a second rectangular transition waveguide (3), two E-surface bent waveguides (4 and 5) are sequentially connected behind each second rectangular transition waveguide (3), and the two E-surface bent waveguides (5) at the tail end are connected with a second magic T (6); the medium square waveguide of the waveguide separator (2) is connected with the orthogonal mode coupler (9); the orthogonal mode coupler (9) outputs two Ka sum channels, and the first magic T and the second magic T respectively output one Ka difference channel.

2. The Ka frequency band multi-horn single-pulse feed network of claim 1, wherein the multi-horn feed system (1) is a 9-horn combined feed system.

3. The Ka band multi-horn monopulse feed network of claim 2, wherein four horns in the 9-horn combined feed system are used for improving signals and have no output, and the other five horns each have an output end; the input end of the waveguide separator (2) is five square waveguide input ends corresponding to five output ends of the 9-horn combined feed source system, and the five square waveguide input ends are distributed in a cross shape, wherein the four peripheral square waveguide input ends change output signals of the four horns into rectangular waveguides through a square moment natural transition structure and output the rectangular waveguides to the rectangular waveguide output end on the side face of the waveguide separator (2) through a bent waveguide impedance matching structure, and the middle square waveguide input end outputs the output signal of the other horn to the dielectric square waveguide at the rear end of the waveguide separator (2).

4. The Ka-band multi-horn single-pulse feed network of claim 1, wherein the dielectric square waveguide is a square transition waveguide with a large rear end and a small front end, and the front end of the dielectric square waveguide is inserted into an air waveguide of the waveguide separator (2) to form the air dielectric transition waveguide.