Stacked Resonant Antenna Array Structure with Slow Wave Effect

Abstract

A stacked resonant antenna array structure with a slow wave effect includes: an antenna unit layer, a metal ground unit layer and a feed unit layer arranged in sequence, wherein: a plurality of stacked resonant antenna subunits are arranged in parallel in the antenna unit layer, and the stacked resonant antenna subunits form an array along a straight line; a plurality of rectangular gaps are arranged on the metal ground unit layer to couple the signal to the stacked resonant antenna subunits; a coplanar waveguide, a strip line and a vertical switching structure therebetween are arranged in the feed unit layer. The present invention significantly improves the propagation constant of the rectangular resonant cavity in the vertical direction by arranging periodically arranged metal diaphragms inside the rectangular resonant cavity, thereby reducing the antenna aperture and making the antenna unit more compact. At the same time, by loading short branches on the metal feeder, the impedance matching of the stacked antenna unit is improved.

Description

Technical Field

[0001] The present invention relates to a technology in the field of antennas, and specifically to a stacked resonant antenna array structure with a slow-wave effect. Background Art

[0002] With the continuous development of electronic communication technologies, the demand for array antennas in communication devices is increasing. Especially in MIMO communication systems and phased array radar systems, only when the antenna array elements are small enough can more antenna elements be placed in a limited area, thereby improving the communication channel capacity and expanding the scanning angle of the radar. When using a stacked resonant antenna in this form as an antenna element, its lateral size is relatively large, making it difficult to meet the requirement of being less than half the wavelength in vacuum. Summary of the Invention

[0003] Aiming at the above deficiencies existing in the prior art, the present invention proposes a stacked resonant antenna array structure with a slow-wave effect. By arranging periodically arranged metal diaphragms inside a rectangular resonant cavity, the propagation constant in the vertical direction of the rectangular resonant cavity is significantly increased, thereby reducing the antenna aperture and making the antenna element more compact. At the same time, by loading short stubs on the metal feeder line, the impedance matching of the stacked antenna element is improved.

[0004] The present invention is realized through the following technical solutions:

[0005] The present invention relates to a stacked resonant antenna array structure with a slow-wave effect, including: an antenna element layer, a metal ground element layer, and a feeding unit layer arranged in sequence, wherein: a plurality of stacked resonant antenna sub-units are arranged in parallel in the antenna element layer, and the stacked resonant antenna sub-units form an array along a straight line.

[0006] Both the antenna element layer and the feeding unit layer include: a plurality of groups of metal layers and dielectric layers arranged alternately.

[0007] The stacked resonant antenna sub-unit includes: an upper metal ring strip arranged on each metal layer except the top layer, an upper metallized via array arranged in each dielectric layer, a periodic metal diaphragm arranged on each metal layer, and a plurality of rectangular resonant cavities arranged in the metal layer and the dielectric layer, wherein: the upper metal ring strip and the upper metallized via array are vertically intersecting and jointly form the outer wall of the rectangular resonant cavity.

[0008] A corresponding rectangular slit is provided directly below the axis of each stacked resonant antenna sub-unit on the metal ground element layer for coupling the signal to the stacked resonant antenna sub-unit.

[0009] The feed unit layer is provided with a coplanar waveguide and a strip line, wherein: the coplanar waveguide and the strip line are connected by a vertical transition structure to form a metal feed line, a lower metalized via array is provided on both sides of the metal feed line, and a lower metal ring strip perpendicularly intersecting the lower metalized via array is provided on the metal layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a three-dimensional schematic diagram of a 3×1 stacked resonant antenna array structure;

[0011] Figure 2 It is a side view of the 3×1 stacked resonant antenna array structure;

[0012] Figure 3 It is a schematic diagram of the specific structure of the stacked resonant antenna unit;

[0013] Figure 4 It is a three-dimensional schematic diagram of a 6×1 stacked resonant antenna array structure;

[0014] Figure 5 It is a top view of the 6×1 stacked resonant antenna array structure;

[0015] Figure 6 It is a side view of the 6×1 stacked resonant antenna array structure;

[0016] Figure 7 is a graph showing the change in the resonant frequency of the stacked resonant antenna unit as a function of the width of the periodic metal diaphragm;

[0017] Figure 8 It is the return loss curve of 6×1 stacked resonant antenna array;

[0018] Figure 9 This is the gain curve of 6×1 stacked resonant antenna array;

[0019] Figure 10 The E-plane radiation pattern of the 6×1 stacked resonant antenna array;

[0020] Figure 11 It is the H-plane radiation pattern of 6×1 stacked resonant antenna array;

[0021] In the figure: 1 antenna unit layer, 2 metal ground unit layer, 3 feed unit layer, 4 coplanar waveguide, 5 vertical switching structure, 6 strip line, 7 short branch, 8 lower metal ring strip, 9 lower metalized via array, 10 rectangular slot, 11 stacked resonant antenna unit, 12 periodic metal diaphragm, 13 upper metal ring strip, 14 upper metalized via array, 15 rectangular resonant cavity, 16 metal layer, 17 dielectric layer. DETAILED DESCRIPTION

[0022] like Figure 1 and Figure 2As shown, this embodiment relates to a miniaturized stacked resonant antenna array structure, including an antenna unit layer 1, a metal ground unit layer 2 and a feeding unit layer 3 arranged in sequence, wherein: a plurality of stacked resonant antenna sub-units 11 are arranged in parallel in the antenna unit layer 1.

[0023] The stacked resonant antenna subunits 11 are arranged in a straight line and can be arranged horizontally or vertically according to actual needs. The array element spacing is one waveguide wavelength in the metal feed line. The number of subunits is but not limited to Figures 1 - 3 3 shown.

[0024] like Figure 2 As shown, the antenna unit layer 1 and the feed unit layer 3 both include: a plurality of groups of metal layers 16 and dielectric layers 17 that are staggered.

[0025] like Figure 3 As shown, the stacked resonant antenna subunit 11 includes: an upper metal ring strip 13 arranged on each metal layer 16 other than the top layer, an upper metallized via array 14 arranged in each dielectric layer 17, a periodic metal diaphragm 12 arranged in each metal layer 16, and a plurality of rectangular resonant cavities 15 arranged in the metal layer 16 and the dielectric layer 17, wherein: the upper metal ring strip 13 and the upper metallized via array 14 intersect vertically and together constitute the outer wall of the rectangular resonant cavity 15.

[0026] The periodic metal diaphragms 12 are arranged in the vertical direction and symmetrically distributed on both sides of the inner wall of the rectangular resonant cavity 15, so as to realize the miniaturization of the stacked resonant antenna.

[0027] The periodic metal diaphragms 12 are all configured as rectangular diaphragms of the same size, and their shapes can be designed according to actual needs.

[0028] The top of the rectangular resonant cavity 15 is an open structure. When the antenna is working, the rectangular resonant cavity 15 resonates in the main mode TE 101 mode and radiates electromagnetic energy into space.

[0029] A corresponding rectangular slot 10 is provided on the metal ground unit layer 2 directly below the axis of each stacked resonant antenna subunit 11 for coupling the signal to the stacked resonant antenna subunit 11. The size of each rectangular slot 10 can be individually set according to the requirements of the array antenna radiation pattern.

[0030] The feed unit layer 3 is provided with a coplanar waveguide 4 and a strip line 6, wherein: the coplanar waveguide 4 and the strip line 6 are connected by a vertical transfer structure 5 to form a metal feed line, and a lower layer metalized via array 9 is provided on both sides of the metal feed line, and a lower layer metal ring strip 8 vertically intersecting the lower layer metalized via array 9 is provided on the metal layer.

[0031] A number of short stubs 7 are provided on the strip line 6 to improve the impedance matching of the antenna unit. The spacing of the short stubs 7 is preferably the same as the spacing of the rectangular slots 10 on the metal ground unit layer 2, and the size of each short stub 7 can be set individually according to the requirements of impedance matching.

[0032] The spacing of the lower metallized via array 9 is less than half of the operating wavelength to suppress higher-order modes.

[0033] As Figure 4 As shown, the operating frequency of the miniaturized 6×1 stacked resonator antenna array structure is 60 GHz. The overall structure is fabricated by a low-temperature co-fired ceramic process. Among them, the low-temperature co-fired ceramic substrate has a dielectric constant of 5.9, a loss tangent of 0.002, each dielectric layer has a thickness of 0.096 mm, each metal layer has a thickness of 0.01 mm, and the planar size of the dielectric board is 4 mm×13.9 mm. If the operating frequency changes, the size of the dielectric board also changes accordingly.

[0034] As Figure 4 As shown, the stacked resonator antenna array structure includes six stacked resonator antenna sub-units 11 arranged in a straight line. The planar size of each stacked resonator antenna sub-unit 11 is 1.8 mm×1.3 mm, the element spacing is 1.92 mm, and the planar size of all the metal diaphragms in the periodic metal diaphragm 12 is 0.9 mm×0.23 mm.

[0035] As Figure 5 As shown, the metallized via diameter of the upper metallized via array 14 and the lower metallized via array 9 of the miniaturized 6×1 stacked resonator antenna array structure is 0.1 mm, and the spacing between adjacent metallized vias is equal, set to 0.25 mm. The strip width of the upper metal ring strip 13 and the lower metal ring strip 8 is 0.2 mm.

[0036] The planar size of all the rectangular slots 10 is 0.7 mm×0.1 mm, and the spacing of the rectangular slots 10 is 1.92 mm.

[0037] The overall antenna structure adopts a series feeding form. The planar size of all the short stubs 7 is 0.4 mm×0.15 mm, the spacing of the short stubs 7 is 1.92 mm, and the planar size of the strip line is 0.2 mm×11.2 mm.

[0038] As Figure 6 As shown, the antenna unit layer 1 of the miniaturized 6×1 stacked resonator antenna array structure includes 4 dielectric boards, and the feeding unit layer 3 includes 2 dielectric boards.

[0039] As Figure 7As shown, it is a graph of the resonant frequency of the stacked resonant antenna sub-unit 11 varying with the width of the periodic metal diaphragm 12. As the width of the periodic metal diaphragm 12 increases, the resonant frequency of the stacked resonant antenna sub-unit 11 gradually decreases.

[0040] As Figure 8 shown, it is the reflection coefficient curve of the 6×1 stacked resonant antenna array structure. Its -10dB impedance bandwidth range is 57.2GHz to 62.7GHz, and the bandwidth is 5.5GHz.

[0041] As Figure 9 shown, it is the gain curve of the 6×1 stacked resonant antenna array structure. Its maximum gain is 11.3dBi, and the 3dB gain bandwidth range is 57.3GHz to 62.7GHz, and the bandwidth is 5.4GHz.

[0042] As Figure 10 shown, it is the E-plane radiation pattern of the 6×1 stacked resonant antenna array structure. The 3dB main lobe beam width is 22°, and the cross-polarization level is less than -45dB.

[0043] As Figure 11 shown, it is the H-plane radiation pattern of the 6×1 stacked resonant antenna array structure. The 3dB main lobe beam width is 82°, and the maximum cross-polarization level is -32.6dB.

[0044] Compared with the prior art, the present invention significantly reduces the volume of the antenna unit through the periodic metal diaphragm. While the structural design is simple and convenient for processing, it reduces the element spacing, making the array antenna more compact. More antenna units can be accommodated in the same area, improving the communication channel capacity. The present invention improves the impedance matching of the stacked resonant antenna unit and expands the operating bandwidth of the array antenna by loading short stubs on the metal feeder, and is applicable to millimeter-wave communication and millimeter-wave radar.

[0045] The above specific implementation can be locally adjusted in different ways by those skilled in the art without departing from the principles and purposes of the present invention. The protection scope of the present invention is subject to the claims and is not limited by the above specific implementation. All implementation solutions within its scope are subject to the constraints of the present invention.

Claims

1. A stacked resonant antenna array structure with a slow wave effect, characterized in that include: It comprises an antenna unit layer, a metal ground unit layer and a feeding unit layer which are arranged in sequence, wherein: a plurality of stacked resonant antenna sub-units are arranged in parallel in the antenna unit layer, and the stacked resonant antenna sub-units form an array along a straight line; The antenna unit layer and the feed unit layer both include: a plurality of groups of metal layers and dielectric layers arranged alternately; The stacked resonant antenna subunit comprises: an upper metal ring strip arranged on each metal layer other than the top layer, an upper metallized via array arranged in each dielectric layer, a periodic metal diaphragm arranged in each metal layer, and a plurality of rectangular resonant cavities arranged in the metal layer and the dielectric layer, wherein: the upper metal ring strip and the upper metallized via array intersect vertically, and together constitute the outer wall of the rectangular resonant cavity; The periodic metal diaphragms are arranged in the vertical direction and symmetrically distributed on both sides of the inner wall of the rectangular resonant cavity; The feed unit layer is provided with a coplanar waveguide and a strip line, wherein: the coplanar waveguide and the strip line are connected by a vertical transition structure to form a metal feed line, a lower metalized via array is provided on both sides of the metal feed line, and a lower metal ring strip perpendicularly intersecting the lower metalized via array is provided on the metal layer.

2. The stacked resonant antenna array structure with slow wave effect according to claim 1, characterized in that, The periodic metal diaphragms are all configured as rectangular diaphragms with the same size.

3. The stacked resonant antenna array structure with slow wave effect according to claim 1, characterized in that, The top of the rectangular resonant cavity is an open structure. When the antenna is working, the rectangular resonant cavity resonates in the main TE mode and radiates electromagnetic energy into space.

4. The stacked resonant antenna array structure with slow wave effect according to claim 1, characterized in that, A corresponding rectangular slot is provided on the metal ground unit layer just below the axis of each stacked resonant antenna subunit, for coupling the signal to the stacked resonant antenna subunit.

5. The stacked resonant antenna array structure with slow wave effect according to claim 1, characterized in that, The strip line is provided with a plurality of short branches for improving the impedance matching of the antenna unit, and the spacing between the short branches is consistent with the spacing between the rectangular gaps on the metal ground unit layer.

6. The stacked resonant antenna array structure with slow wave effect according to claim 1, characterized in that, The spacing of the lower metallized via array is less than half of the operating wavelength.

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