CN104795639B - A Compact Circularly Polarized Microstrip Antenna and Its Antenna Array - Google Patents

Abstract

The present invention is a kind of compact circularly-polarized microstrip antenna and its antenna array, circular polarization microstrip antenna levels dielectric-slab and substrate are identical square, square radiation patch is attached at top dielectric plate upper surface, substrate is attached at layer dielectric plate upper surface, and microstrip feed line is attached at the lower surface of layer dielectric plate.It is air layer between substrate and top dielectric plate.The center of substrate have in length and breadth groove be mutually perpendicular to the cross recess divided equally, the radiation patch four of top layer while it is upper per while have 3~7 grooves, the groove on center line is most deep, and grooves on two sides depth is gradually reduced, the groove on four sides using radiation patch center be symmetrical.This compact circularly-polarized microstrip antenna constitutes antenna array for array element.Each power splitter is connected with each array element feeder line, and multiple array elements are arranged in a straight line at grade, or is arranged as quadrate array at grade.The present invention has more preferable circular polarization characteristics, reduces antenna size, and reduction antenna array array element spacing is 0.6 λ, antenna array compact conformation.

Description

A Compact Circularly Polarized Microstrip Antenna and Its Antenna Array

technical field

The invention relates to the technical field of receiving antennas in communication, in particular to a compact circularly polarized microstrip antenna and an antenna array thereof.

Background technique

The circularly polarized microstrip antenna is a patch-shaped antenna composed of a metal copper sheet attached to a medium. The circularly polarized microstrip antenna includes a radiation patch on the top layer, an air layer and a bottom feeder. Circularly polarized microstrip antennas are mainly used for receiving antennas and require better circular polarization characteristics. At present, the circularly polarized microstrip antenna radiation patch has symmetrical grooves of the same depth on the four sides to extend the surface current path of the radiation patch and reduce the size of the antenna. While making the antenna array compact, it also ensures the circular pole of the antenna. characteristics. However, the existence of uniform and symmetrical slots will affect the current distribution in the patch and damage the circular polarization characteristics of the antenna.

The circularly polarized microstrip antenna array is composed of several microstrip antenna elements. Due to the coupling between the antenna elements, in order to reduce the influence of the coupling on the performance of each antenna element, at present, the element spacing of the general microstrip antenna array is 0.5λ (λ is the wavelength of the electromagnetic wave in the medium), the microstrip Due to circular polarization interference, the circularly polarized antenna array has relatively large element spacing, at least 0.83λ, which is not conducive to the miniaturization of the antenna array.

Contents of the invention

The purpose of the present invention is to design a compact circularly polarized microstrip antenna. The grooves on the center line of each side on the four sides of the radiation patch are the deepest, and the depths of the grooves on both sides gradually decrease. The centerlines of each side are symmetrical. The size of the antenna is reduced, the antenna has a compact structure and a small mass.

Another object of the present invention is to design an antenna array formed by a compact circularly polarized microstrip antenna. With the compact circularly polarized microstrip antenna of the present invention as an array element, the mutual spacing of the array elements is reduced to 0.6λ or less , in order to facilitate the miniaturization of the antenna array.

A compact circularly polarized microstrip antenna designed by the present invention includes a top radiation patch, an upper dielectric board, a substrate, a lower dielectric board and a bottom microstrip feeder stacked in sequence, and the upper dielectric board, the substrate and the lower dielectric board are The same square has a side length of S, and the radiation patch is also a square with a side length of s, and S=(1.5˜2.5)s. The radiation patch is attached to the upper surface of the upper dielectric board, the substrate is attached to the upper surface of the lower dielectric board, the microstrip feeder is attached to the lower surface of the lower dielectric board, and the substrate and the radiation patch are copper sheets. The upper dielectric board and the lower dielectric board are insulating dielectric boards. There is an air layer between the upper surface of the substrate and the lower surface of the upper dielectric plate. The centers of the top radiation patch, the upper dielectric board, the substrate and the lower dielectric board are on the same vertical line, and the centerlines of each side are on the same vertical plane. There is a cross groove in the center of the base plate, and the longitudinal groove and the transverse groove of the cross groove are vertically bisected to each other and are respectively parallel to two adjacent sides of the base plate. There are 3 to 7 rectangular grooves on each of the four sides of the radiation patch on the top layer. The center line of the groove is perpendicular to the side where it is located. The groove on the center line of each side is the deepest. The depth of the grooves on both sides of the center line of each side gradually Reduced, the grooves on each side are symmetrical to the center line of each side. The width W of each groove is the same, the distance between the sides of each groove and the distance W' between the outer edge of the groove at both ends of each side and the edge of the radiation patch is greater than W, W'=(1.8-2.2)W. The width W of each groove is 0.1mm-0.3mm, the depth of the groove on the center line of each side is L, L=(0.25-0.35)s, and the depth of the grooves on both sides of the center line of each side decreases proportionally. The grooves on the four sides are symmetrical to the center of the radiation patch.

The substrate and the radiation patch are copper sheets with a thickness of 0.02mm-0.08mm.

The upper dielectric board and the lower dielectric board are insulating dielectric boards with a thickness of 0.5 mm to 2 mm.

The thickness of the air layer between the upper surface of the substrate and the lower surface of the upper dielectric plate is 3 mm to 6 mm.

The groove width Ws of the cross groove is smaller than the width W of the grooves on each side of the radiation patch, W=(1.1˜1.5)Ws.

The length Ls of the cross groove is equal to the side length s of the radiation patch.

An antenna array composed of a compact circularly polarized microstrip antenna designed by the present invention, a plurality of the above-mentioned compact circularly polarized microstrip antennas are array elements to form an antenna array, and the equal fraction of the power divider is the same as the number of array elements , each port of the power divider is connected to the feeder of each array element in the antenna array one by one, and the signal of equal amplitude and same phase is input. The wavelength in the substrate medium; 2 to 7 array elements are arranged in a straight line on the same plane, and the line connecting the centers of the array elements is a straight line, or N×N array elements are arranged in a square array on the same plane, and N is 2 to Integer of 8.

Compared with prior art, the advantage of a kind of compact circularly polarized microstrip antenna of the present invention and the antenna array that constitutes thereof is: 1, the groove that each side of radiator patch changes gradually, prolongs the patch surface current path, At the same time, the radiation patch has better circular polarization characteristics than grooves of the same depth, making the circularly polarized microstrip antenna array compact, while ensuring the narrow beam and circular polarization characteristics of the antenna, greatly reducing the size of the antenna. The patch size of the microstrip antenna radiator is 45mm×45mm, which is reduced to 30mm×30mm, which is reduced by 30%. The spacing between the circularly polarized antenna array elements is 0.83λ, which is reduced to be equal to or less than 0.6λ, which is reduced by 25%, thus reducing the micro Dimensions of an antenna array with circular polarization.

Description of drawings

Fig. 1 is the top view schematic diagram of this compact circularly polarized microstrip antenna embodiment;

Fig. 2 is the schematic diagram of the side view of this compact circularly polarized microstrip antenna embodiment;

Fig. 3 is a schematic diagram of a bottom view of an embodiment of the compact circularly polarized microstrip antenna;

Fig. 4 is the schematic structural diagram of the antenna array embodiment 1 that this compact circularly polarized microstrip antenna forms;

FIG. 5 is a schematic structural diagram of Embodiment 2 of the antenna array composed of the compact circularly polarized microstrip antenna. The labels in the figure are:

1. Upper dielectric board, 2. Radiation patch, 3. Air layer, 4. Substrate, 5. Lower dielectric board, 6. Microstrip feeder, 7. Cross groove.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings.

Compact Circularly Polarized Microstrip Antenna Embodiment

The embodiment of the compact circularly polarized microstrip antenna is shown in Figures 1 to 3, including a radiation patch 2 on the top layer, an upper dielectric board 1, a substrate 4, a lower dielectric board 5 and a microstrip feeder 6 on the bottom layer, which are stacked in sequence. The upper dielectric board 1 , the substrate 4 and the lower dielectric board 5 are the same square with a side length S, and S=60mm in this example. The radiation patch 2 is also a square with side length s, s=30mm. The upper dielectric board 1 is a single-sided copper-clad laminate, and the copper foil with a thickness of 0.05 mm attached to its upper surface is etched into a radiation patch 2. The lower dielectric board 5 is a double-sided copper-clad laminate, and the copper foil with a thickness of 0.05 mm attached to its upper The copper foil is the substrate 4 , and a cross groove 7 is etched in its center. The vertical groove and the horizontal groove of the cross groove 7 are perpendicular to each other and parallel to two adjacent sides of the substrate 4 . The groove width Ws of the cross groove 7 is smaller than the width W of the grooves on each side of the radiation patch 2, in this example W=1.3Ws, and the length Ls of the cross groove 7 is equal to the side length s of the radiation patch 2. The copper foil with a thickness of 0.05 mm attached to the lower surface of the lower dielectric board 5 is etched into a microstrip feeder 6 . The upper dielectric board 1 and the lower dielectric board 5 are insulating dielectric boards with a thickness of d1 = d2 = 5mm. Between the upper surface of the substrate 4 and the lower surface of the upper dielectric plate 1 is an air layer 3 with a thickness d2 = 4.5mm. The centers of the top radiation patch 2 , the upper dielectric board 1 , the substrate 4 and the lower dielectric board 5 are on the same vertical line, and the centerlines of each side of each layer are on the same vertical plane.

There are 5 rectangular grooves on each of the four sides of the radiation patch 2 on the top layer. The center line of the groove is perpendicular to the side where it is located. The groove on the center line of each side is the deepest, and the depth of the groove on both sides of the center line of each side gradually decreases Small, the grooves on each side are symmetrical to the centerline of each side. The width W of each groove is the same, the distance between each groove and the distance W' between the outer side of the groove at both ends of each side and the same side of the radiation patch 2 is greater than W, and in this example W'=2W. The width W of each groove is 0.2mm, the depth of the groove on the center line of each side is L1, L1=10mm, the depth of the grooves on both sides of the center line is successively reduced to L2=7mm, L3=2mm. The grooves on the four sides are symmetrical to the center of the radiation patch.

Embodiment 1 of Antenna Array Formed by Compact Circularly Polarized Microstrip Antennas

The antenna array embodiment 1 that this compact circularly polarized microstrip antenna forms is shown in Figure 4, and 3 above-mentioned compact circularly polarized microstrip antenna embodiments are array elements to form a linear antenna array, and 3 identical power dividers and The feeders of the 3 array elements are connected one by one, and the signals of equal amplitude and phase are input. The 3 array elements are arranged in a straight line on the same plane, and the connection line between the centers of the 3 array elements is a straight line.

In this example, the operating frequency of the microstrip circularly polarized antenna array is 2.4GHz, and the wavelength λ in the substrate medium is 59.55mm. The distance D between the elements of the microstrip circularly polarized antenna array (that is, the distance between adjacent radiation patches) is 35mm, D=0.6λ.

In this example, the return loss bandwidth of the microstrip circularly polarized antenna array is 200MHz, that is, 2.3GHz to 2.5GHz, and the circularly polarized radiation of the antenna, the axial ratio bandwidth is 70MHz, that is, _2.35GHz to _2.42GHz , and the beam angle is 31.5° .

Embodiment 2 of Antenna Array Formed by Compact Circularly Polarized Microstrip Antennas

Embodiment 2 of the antenna array formed by the compact circularly polarized microstrip antenna is shown in Figure 5, and 2×2 above-mentioned compact circularly polarized microstrip antenna embodiments are array elements to form a square array antenna array, and 4 of the same function The splitter is connected to the feeders of the 4 array elements one by one, and the signals of equal amplitude and phase are input, and the 4 array elements are arranged in a 2×2 square array on the same plane.

In this example, the operating frequency of the microstrip circularly polarized antenna array is 2.4 GHz, the wavelength λ in the substrate medium is 59.55 mm, and the distance D between array elements is 35 mm, D=0.6λ.

The above-mentioned embodiments are only specific examples for further specifying the purpose, technical solutions and beneficial effects of the present invention, and the present invention is not limited thereto. Any modifications, equivalent replacements, improvements, etc. made within the disclosed scope of the present invention are included in the protection scope of the present invention.

Claims (7)

1. A compact circularly polarized microstrip antenna, comprising a radiation patch (2), an upper dielectric plate (1), a substrate (4), a lower dielectric plate (5) and a bottom layer of the microstrip stacked in sequence The feeder (6), the upper dielectric board (1), the substrate (4) and the lower dielectric board (5) are the same square with a side length of S, and the radiation patch (2) is also a square with a side length of s. S=(1.5～2.5)s; the radiation patch (2) is attached to the upper surface of the upper dielectric board (1), the substrate (4) is attached to the upper surface of the lower dielectric board (5), and the microstrip feeder (6) is attached to Attached to the lower surface of the lower dielectric board (5), the substrate (4) and the radiation patch (2) are copper sheets; the upper dielectric board (1) and the lower dielectric board (4) are insulating dielectric boards; the upper dielectric board (4) There is an air layer (3) between the surface and the lower surface of the upper dielectric board (1); the centers of the radiation patch (2), the upper dielectric board (1), the substrate (4) and the lower dielectric board (5) are at the same vertical On the line, the center line of each side is on the same vertical plane; it is characterized in that: There is a cross groove (7) in the center of the base plate (4), the longitudinal groove and the transverse groove of the cross groove (7) are perpendicular to each other, and are respectively parallel to the adjacent two sides of the base plate (4), on the base plate (4) The length Ls of the cross groove (7) is equal to the side length s of the radiation patch (2); there are 3 to 7 rectangular grooves on each side of the four sides of the radiation patch (2), and the center line of the groove is in line with the radiation patch ( The sides of 2) are vertical, and the groove on the centerline of each side is the deepest. The depth of the groove on the centerline of each side on the four sides of the radiation patch (2) is L, L=(0.25～0.35)s, each side The depth of the grooves on both sides of the center line is proportionally reduced, the grooves on each side are symmetrical to the center line of each side, and the grooves on the four sides are symmetrical to the center of the radiation patch (2); the radiation patch (2) ) the width W of each groove on the four sides is the same, the distance between the sides of each groove and the distance W' between the outer edge of the groove at both ends of each side and the side of the radiation patch (2) is greater than W, W'=(1.8～2.2)W. 2. The compact circularly polarized microstrip antenna according to claim 1, characterized in that: The width W of each groove on the four sides of the radiation patch (2) is 0.1mm-0.3mm. 3. The compact circularly polarized microstrip antenna according to claim 1, characterized in that: The substrate (4) and radiation patch (2) are copper sheets with a thickness of 0.02 mm to 0.08 mm. 4. The compact circularly polarized microstrip antenna according to claim 1, characterized in that: The upper dielectric board (1) and the lower dielectric board (5) are insulating dielectric boards with a thickness of 0.5 mm to 2 mm. 5. The compact circularly polarized microstrip antenna according to claim 1, characterized in that: The thickness of the air layer (3) between the upper surface of the substrate (4) and the lower surface of the upper dielectric plate (5) is 3 mm to 6 mm. 6. The compact circularly polarized microstrip antenna according to claim 2, characterized in that: The groove width Ws of the cross groove (7) on the substrate (4) is smaller than the width W of the grooves on each side of the radiation patch (2), W=(1.1-1.5)Ws. 7. The antenna array formed by the compact circularly polarized microstrip antenna according to any one of claims 1 to 6, characterized in that: A plurality of the above-mentioned compact circularly polarized microstrip antennas constitute an antenna array as array elements, and the same power dividers with the same number as the array elements are connected to the feeders of each array element in the antenna array one by one, and input signals of equal amplitude and phase , the distance between adjacent array element substrates (4) is 3 mm to 10 mm; 2 to 7 array elements are arranged in a straight line on the same plane, and the lines connecting the centers of the array elements are in a straight line, or N×N array elements are arranged in a straight line. They are arranged in a square array on the same plane, and N is an integer from 2 to 8.