A waveguide narrow sideband frequency scanning antenna for widening the frequency scanning angle range of a traveling wave array

Abstract

The present invention relates to a waveguide narrow-edge frequency scanning antenna for widening the frequency scanning angle range of a traveling wave array, and belongs to the field of antenna technology. On the basis of an ordinary waveguide narrow-edge traveling wave antenna, by adding a funnel-shaped metal branch, the ordinary straight waveguide is improved into a new type of waveguide narrow-edge slow-wave linear waveguide, and the frequency scanning angle range of the linear array is expanded to three times that of the ordinary waveguide. The waveguide narrow-edge slot antenna array composed of the wide-angle waveguide narrow-edge oblique slot frequency scanning linear array has the characteristics of low cost and wide-angle phase frequency scanning, and can be widely used in the field of low-cost and high-performance reconnaissance radar.

Description

Technical Field

[0001] The invention belongs to the field of antenna technology and proposes a design method for a waveguide narrow sideband frequency scanning antenna for widening the frequency scanning angle range of a traveling wave array, which can be widely used in the field of low-cost, high-performance reconnaissance radars. Background Art

[0002] Two-dimensional active phased array antennas have the advantages of flexible beam scanning and high target measurement accuracy, but at this stage they face problems such as high cost, high power consumption, and high heat dissipation requirements. Compared with two-dimensional active phase-scanning antennas, phase-frequency scanning antennas have been deeply studied and applied in recent years due to their low cost and ability to achieve two-dimensional scanning. Frequency scanning antennas have the advantages of simple form, compact structure, low cost, and fast beam switching speed, which are more conducive to the integration and miniaturization of the system, but their disadvantage is that the achievable scanning angle range within the frequency band is small. For example, in a certain working frequency band, the waveguide slot antenna made of ordinary straight waveguide has a maximum frequency scanning angle range of about 10 degrees within a bandwidth of 11%, and the achievable frequency scanning angle range is small.

[0003] The disadvantage of the frequency scanning antenna is that the scanning range is small. The introduction of slow wave line structure can solve this problem. Microstrip slow wave line, stripline slow wave line, and coplanar waveguide slow wave line have the advantages of low profile and light weight. The wide-angle microstrip frequency scanning antenna array has been widely studied and applied, but this type of slow wave line has large loss in the millimeter wave band and cannot meet the use requirements. In recent years, composite left-handed and right-handed materials have been applied to frequency scanning antenna arrays to achieve low side lobes and wide-angle multi-scanning, but this material is difficult to implement in engineering. In addition, substrate integrated waveguide slot wide-angle frequency scanning antenna array has also become a research hotspot, but this array is wide and cannot be applied to wide-angle phase frequency scanning array. The waveguide slow wave line has low loss. The current reports focus on the method of bending along the waveguide E surface to form a slow wave line, but the wide-angle frequency scanning array formed by this structural form usually has the disadvantages of large volume and weight, and cannot be applied to antenna arrays for one-dimensional wide-angle frequency control scanning and another-dimensional phase control scanning. Summary of the invention

[0004] Technical issues to be solved

[0005] In order to overcome the problem of limited frequency scanning range of existing frequency scanning antenna arrays, the present invention proposes a waveguide narrow-side frequency scanning antenna that widens the frequency scanning angle range of a traveling wave array.

[0006] Technical Solution

[0007] A waveguide narrow-edge frequency-scanning antenna for widening the frequency-scanning angle range of a traveling wave array, characterized in that funnel-shaped metal branches are periodically and evenly loaded on the upper and lower edges of the narrow edge of the waveguide, with a periodic spacing of d2, and an oblique slit is opened on the narrow edge of the waveguide so that the antenna radiates electromagnetic wave energy into space, and the slit period is d1, and the relationship is: d1=2×d2.

[0008] The funnel-shaped metal branch node is composed of a triangular part and a rectangular part, the size of the triangular part is h1×b1, the size of the rectangular part is h2×b2, h is the total depth of the funnel-shaped branch node, and h=h1+h2; adjusting the sizes of h1, b1, h2, and b2 of the funnel-shaped metal branch node can achieve impedance matching of the waveguide narrow-side slow-wave line, ensuring that the waveguide narrow-side slot antenna can efficiently radiate radio frequency energy.

[0009] An array antenna composed of the waveguide narrow-side frequency scanning antennas for widening the frequency scanning angle range of the traveling wave array, characterized in that it includes 6 waveguide narrow-side frequency scanning antennas.

[0010] Beneficial Effects

[0011] The present invention proposes a waveguide narrow-edge frequency scanning antenna that widens the frequency scanning angle range of the traveling wave array, which can efficiently expand the frequency scanning angle range within the waveguide narrow-edge slant slot frequency scanning array band. The waveguide narrow-edge slot active antenna array composed of the wide-angle waveguide narrow-edge slant slot frequency scanning line array has the technical advantages of low cost and wide-angle phase frequency scanning, and can be widely used and promoted in engineering practice. Compared with the prior art, low loss and large frequency scanning range: the present invention realizes a small waveguide narrow-edge slow wave line structure by periodically and evenly loading funnel-shaped metal branches. The structure has the characteristics of small size and low loss, and at the same time widens the frequency scanning angle range of the waveguide narrow-edge slant slot frequency scanning antenna (the frequency scanning range is 31.5 degrees within the 10.7% bandwidth, and the frequency scanning range of the traditional waveguide is 10 degrees). BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of the waveguide narrow-side funnel-type slow-wave line structure

[0013] Figure 2 Schematic diagram of the wide-angle waveguide narrow sideband swept line array of the present invention

[0014] Figure 3 The in-band frequency scanning pattern curve of the waveguide narrow side frequency scanning antenna with wide frequency scanning angle DETAILED DESCRIPTION

[0015] The present invention will now be further described with reference to the embodiments and the accompanying drawings:

[0016] In view of the shortcomings of traditional waveguide narrow-sideband frequency-scanning antennas, the present invention realizes a waveguide narrow-sideband frequency-scanning antenna with low loss and wide frequency-scanning angle range through the following structure, and finally forms an array to form a low-cost, large-scanning-angle phase-frequency-scanning antenna array.

[0017] The wide-angle waveguide narrow-side slanted slot frequency scanning antenna of the present invention improves the ordinary straight waveguide into a new type of waveguide narrow-side slow-wave line structure waveguide by adding funnel-shaped metal branches on the basis of the ordinary waveguide narrow-side traveling wave antenna, thereby doubling the frequency scanning angle range of the linear array.

[0018] The first step is to periodically and evenly load funnel-shaped metal branches (1) on the upper and lower edges of the narrow side of the waveguide, with a periodic spacing of d2. Slanted slits are opened on the narrow side of the waveguide so that the antenna radiates electromagnetic wave energy into space. The slit period is d1, and the relationship is: d1 = 2 × d2. The size of the wide side of the entire waveguide cavity is a, and the size of the narrow side of the waveguide is determined by the linear array spacing d. x Determined. The periodic funnel-shaped metal branch (1) is composed of a triangular part (11) and a rectangular part (12). The size of the triangular part (11) is h1×b1, and the size of the rectangular part (12) is h2×b2. h is the total depth of the funnel-shaped branch, and h=h1+h2. The size of h determines the frequency sweep angle range. The larger h is, the larger the frequency sweep angle range within the fixed frequency band. Reasonable adjustment of the sizes of the funnel-shaped branches h1, b1, h2, and b2 can achieve impedance matching of the waveguide narrow-side slow-wave line, ensuring that the waveguide narrow-side slot antenna can efficiently radiate radio frequency energy. Reference Figure 1 , Figure 2 .

[0019] In the second step, the waveguide narrow sideband frequency scanning antenna linear arrays that widen the frequency scanning angle range of the traveling wave array are alternately arrayed, that is, symmetrical along the axis, in order to suppress cross polarization. The unit spacing of the linear array is d x , which is determined by the phase scanning angle. Figure 2 .

[0020] Embodiment: Within the 10.7% working bandwidth of the Ku band (frequency 14.2 GHz to 15.8 GHz), the waveguide wide side dimension a=20 mm, the narrow side dimension b=7 mm, when the waveguide gap spacing d1=12 mm, the period d2=6 mm of the funnel-shaped branches is obtained, and the frequency scanning range of the waveguide narrow side traveling wave antenna is changed by adjusting the depth of h. Taking h=8 mm, when h1=3 mm, h2=5 mm, b1=5 mm, and b2=1 mm, the waveguide is matched in this frequency band and can efficiently propagate electromagnetic waves.

[0021] Figure 3 The in-band frequency sweep pattern curve of the waveguide narrow-edge frequency sweep antenna with widened frequency sweep angle. Within the working bandwidth of 10.7%, the frequency sweep angle range is 31.5 degrees.

Claims

1. A waveguide narrow sideband frequency scanning antenna for widening the frequency scanning angle range of a traveling wave array, characterized in that Funnel-shaped metal branches (1) are periodically and evenly loaded on the upper and lower edges of the narrow side of the waveguide, the periodic spacing between the upper branch and the lower branch is d2, and an oblique slit is opened on the narrow side of the waveguide so that the antenna radiates electromagnetic wave energy into space, the slit period is d1, and the relationship is: d1 = 2 × d2; the funnel-shaped metal branch (1) is composed of a triangular part (11) and a rectangular part (12), the size of the triangular part (11) is h1 × b1, the size of the rectangular part (12) is h2 × b2, h is the total depth of the funnel-shaped branch, h = h1 + h2; adjusting the sizes of h1, b1, h2, and b2 of the funnel-shaped metal branch (1) can achieve impedance matching of the slow wave line of the narrow side of the waveguide, thereby ensuring that the narrow side slot antenna of the waveguide can radiate radio frequency energy efficiently.

2. An array antenna composed of the waveguide narrow sideband frequency scanning antenna for widening the frequency scanning angle range of the traveling wave array as claimed in claim 1, characterized in that Includes 6 waveguide narrow-sideband frequency-scanning antennas.

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