CN206098694U - A Microstrip Array Antenna - Google Patents

Abstract

The utility model relates to a microstrip array antenna. Compared with the prior art, the utility model solves the defects that the microstrip array antenna is difficult to miniaturize, has high gain and low side lobe. The dielectric substrate of the utility model is circular, and 52 microstrip antenna units are arranged on the upper surface of the dielectric substrate, and a quarter wavelength conversion section is connected to the 52 microstrip antenna units. Based on the Y-axis direction of the dielectric substrate, it is divided into eight transverse sequences. The quarter-wavelength conversion sections of the microstrip antenna units in each transverse sequence are connected by a three-quarter-wavelength transmission line. The first transverse sequence and the eighth transverse sequence Each sequence has 4 microstrip antenna units, the second transverse sequence and the seventh transverse sequence both have 6 microstrip antenna units, the third transverse sequence, the fourth transverse sequence, the fifth transverse sequence and the sixth transverse sequence all have 8 A microstrip antenna unit. The utility model reduces the volume of the antenna, and simultaneously obtains larger gain and lower side lobe.

Description

A Microstrip Array Antenna

technical field

The utility model relates to the technical field of microstrip antennas, in particular to a microstrip array antenna.

Background technique

Microstrip antenna has the characteristics of light weight, small volume, thin section and easy array formation. Compared with reflector antenna and horn antenna, it is easier to meet the design requirements of array antenna, and its manufacturing cost is low, so it is widely used in various fields. In actual application, according to different application scenarios, it is difficult to meet the requirements of the microstrip unit structure such as antenna with strong directivity, high gain and low sidelobe, which requires the use of microstrip antenna unit array to meet the requirements of strong directivity, high gain , Low sidelobe application requirements.

In the prior art, the structure of a common microstrip array antenna is shown in FIG. 1 , which is mainly composed of a dielectric substrate, a ground plate, several radiation elements, a waveguide-microstrip conversion connection part and a metal waveguide part. The radiating elements (microstrip antenna elements) are evenly arranged in the horizontal (X-axis) and vertical (Y-axis) two-dimensional directions, the number of radiating elements remains unchanged in the vertical and horizontal two-dimensional directions, and the radiating elements are arranged in a rectangular shape as a whole . The waveguide-microstrip conversion connection part has an opposite A surface and a B surface, and the A surface and the B surface are electrically connected through several through holes.

In the case of keeping the antenna radiation direction characteristic index unchanged, if it is necessary to carry out miniaturization design and reduce the planar size of the microstrip array antenna, it will be difficult for this kind of microstrip array to meet the requirements, and the method of sacrificing the performance index of the antenna can only be adopted to achieve miniaturization. Therefore, how to realize miniaturization, high gain and low sidelobe of the microstrip array antenna has become an urgent technical problem to be solved.

Utility model content

The purpose of this utility model is to provide a microstrip array antenna to solve the above-mentioned problems in order to solve the defects of the microstrip array antenna in the prior art that it is difficult to miniaturize, have high gain and low sidelobes.

In order to achieve the above object, the technical scheme of the utility model is as follows:

A microstrip array antenna, comprising a dielectric substrate and a conductive ground plate installed on the lower surface of the dielectric substrate,

The dielectric substrate is circular, and the upper surface of the dielectric substrate is provided with 52 microstrip antenna units, and the 52 microstrip antenna units are connected with a quarter wavelength conversion section, and the 52 microstrip antenna units are on the dielectric substrate. Based on the Y-axis direction of the dielectric substrate, it is divided into eight transverse sequences, and the quarter-wavelength conversion sections of the microstrip antenna units in each transverse sequence are connected by three-quarter wavelength transmission lines, the first transverse sequence and the eighth transverse sequence Both have 4 microstrip antenna units, the second transverse sequence and the seventh transverse sequence both have 6 microstrip antenna units, and the third transverse sequence, the fourth transverse sequence, the fifth transverse sequence and the sixth transverse sequence each have 8 Microstrip antenna unit;

The central points of the three-quarter wavelength transmission lines of the eight transverse sequences are all connected in series with the main quarter-wavelength impedance converter, and the eight main quarter-wavelength impedance converters are connected in series through the main transmission line to form a feed network, and the waveguide - The coaxial backfeed connector is installed at the center of the main transmission line.

The waveguide-coaxial backfeed joint includes a standard waveguide, the standard waveguide is embedded with an L-shaped coaxial probe, and the L-shaped coaxial probe is embedded in the standard waveguide for half the waveguide wavelength and then connected to the side where the wide side of the standard waveguide is located .

The excitation current amplitude ratios of the quarter-wavelength conversion section of the first transverse sequence and the quarter-wavelength conversion section of the eighth transverse sequence are both 0.5096:1:1:0.5096, and the The order of the excitation current amplitude ratios of the quarter-wavelength conversion section and the quarter-wavelength conversion section of the seventh transverse sequence is 0.4447:0.7224:1:1:0.7224:0.4447, and a quarter of the third transverse sequence The excitation current amplitude ratio sequence of the first wavelength conversion section, the quarter wavelength conversion section of the fourth transverse sequence, the quarter wavelength conversion section of the fifth transverse sequence and the quarter wavelength conversion section of the sixth transverse sequence Both are 0.4235:0.5937:0.8317:1:1:0.8317:0.5937:0.4235.

The order of excitation current amplitude ratios of the eight main quarter wavelength impedance converters on the main transmission line is 0.4235:0.5937:0.8317:1:1:0.8317:0.5937:0.4235.

The thickness of the dielectric substrate is 10mil, the dielectric constant is 2.94, and the loss tangent angle δ is 0.0012.

The diameter of the dielectric substrate is 50 mm.

The distance between the 52 microstrip antenna elements is one waveguide wavelength.

The wide side of the standard waveguide is 5.69mm, and the narrow side is 2.845mm.

Beneficial effect

Compared with the prior art, the microstrip array antenna of the utility model reduces the volume of the antenna, and simultaneously obtains larger gain and lower side lobe. The utility model adopts the waveguide-coaxial backfeed joint to realize power feeding to the center of the microstrip array antenna, which can solve the problem of high installation precision of the conventional waveguide feeding method due to the structural size limitation of the antenna product. At the same time, based on the Taylor synthesis method to calculate the excitation current distribution, the arrangement and array design of the microstrip antenna units reduces the sidelobe level of the antenna, and has the advantages of high gain, low sidelobe level and easy integration.

Description of drawings

FIG. 1 is a schematic structural diagram of a microstrip array antenna in the prior art;

Fig. 2 is the structural top view of the utility model;

Fig. 3 is the installation structure diagram of the dielectric substrate and the conductive grounding plate in the utility model;

Fig. 4 is a structural side view of the waveguide-coaxial backfeed joint in the utility model;

Fig. 5 is a schematic diagram of the gain simulation results of the microstrip array antenna described in the present invention;

Among them, 1-dielectric substrate, 2-microstrip antenna unit, 3-conductive ground plate, 4-quarter wavelength conversion section, 5-three-quarter wavelength transmission line, 6-main quarter-wavelength impedance converter , 7-main transmission line, 8-waveguide-coaxial backfeed connector, 9-standard waveguide, 10-L-type coaxial probe.

detailed description

In order to have a further understanding and understanding of the structural features and the achieved effects of the utility model, a detailed description is provided in conjunction with preferred embodiments and accompanying drawings, as follows:

As shown in FIG. 3 , a microstrip array antenna according to the present invention includes a dielectric substrate 1 and a conductive ground plate 3 installed on the lower surface of the dielectric substrate 1 . As shown in FIG. 2 , the dielectric substrate 1 is circular, the thickness of the dielectric substrate 1 is 10 mil, the dielectric constant is 2.94, and the loss tangent angle δ is 0.0012. The upper surface of the dielectric substrate 1 is provided with 52 microstrip antenna units 2, and each of the 52 microstrip antenna units 2 is connected with a quarter-wavelength conversion section 4. The circular design of the dielectric substrate 1 is adopted to reduce the area of the antenna . The diameter of the dielectric substrate 1 is 50 mm, that is, the diameter of the antenna is 50 mm.

52 microstrip antenna units 2 are arranged in eight horizontal sequences on the dielectric substrate 1 based on the Y-axis direction of the dielectric substrate 1. The antenna units 2 are divided into eight horizontal sequences. Wherein, the number of microstrip antenna units 2 of the first transverse sequence and the eighth transverse sequence are the same as 4, the number of microstrip antenna units 2 of the second transverse sequence and the seventh transverse sequence are the same as 6, and the third transverse sequence The number of microstrip antenna units 2 in the fourth, fifth, and sixth horizontal sequences is the same as 8. Therefore, the descending or ascending order of the eight horizontal sequences based on the Y axis can be used as a reference. The integral structure of the microstrip antenna unit 2 on the dielectric substrate 1 further reduces the area of the antenna, and has the advantages of high gain, low sidelobe level, simple structure, and easy fabrication.

In the eight transverse sequences, the quarter-wavelength conversion section 4 of the microstrip antenna unit 2 in each transverse sequence is connected by a three-quarter-wavelength transmission line 5, that is, there are 8 three-quarter wavelength transform sections on the dielectric substrate 1. Wavelength transmission line 5. The central points of the three-quarter wavelength transmission lines 5 of the eight transverse sequences are all connected in series with main quarter-wavelength impedance converters 6, and similarly, there are eight main quarter-wavelength impedance converters 6, and eight main ones The quarter-wavelength impedance converters 6 are connected in series through the main transmission line 7 to form a feed network, and the feed network thus formed has the effect of reducing side lobes.

The waveguide-coaxial backfeed connector 8 is installed at the center of the main transmission line 7, and the waveguide-coaxial backfeed connector 8 has the functions of simple structure and easy assembly. As shown in FIG. 4 , the waveguide-coaxial backfeed joint 8 includes a standard waveguide 9 whose wide side is 5.69 mm and narrow side is 2.845 mm. An L-shaped coaxial probe 10 is embedded in the standard waveguide 9, and the L-shaped coaxial probe 10 is embedded in the standard waveguide 9 for half the waveguide wavelength and then connected to the side where the wide side of the standard waveguide 9 is located.

The working frequency of the array antenna described in the present invention can be 35.15 GHz. Based on this working frequency, the distance between 52 microstrip antenna units 2 can be designed as one waveguide wavelength. The excitation current distribution is calculated based on the Taylor synthesis method, and the specific structural parameters of the microstrip antenna unit 2, the three-quarter wavelength transmission line 5, the quarter wavelength conversion section 4 and the main quarter wavelength impedance converter 6 can be carried out. design. The array designed by the Taylor synthesis method, its pattern has sidelobe characteristics that gradually decrease as the angle away from the main lobe increases, and based on this, the quarter-wavelength conversion section 4 of the first transverse sequence and the eighth transverse sequence are designed. The excitation current amplitude ratios of the quarter-wavelength conversion section 4 are all in the order of 0.5096:1:1:0.5096. That is, the excitation current amplitude ratios of the four microstrip antenna units 2 included in the first or eighth transverse sequence are all 0.5096:1:1:0.5096 in the first or eighth transverse sequence. Based on this excitation current amplitude ratio sequence, the characteristic impedance value of the quarter wavelength conversion section 4 is designed according to the prior art method, and then the width and length of the quarter wavelength conversion section 4 are obtained by using the characteristic impedance value, and the microstrip antenna unit The dimension parameters such as width, length, insertion depth and slot width of 2 can be designed according to the prior art method according to the parameters of the dielectric substrate and the working frequency.

Similarly, the excitation current amplitude ratios of the quarter-wavelength conversion section 4 of the second transverse sequence and the quarter-wavelength conversion section 4 of the seventh transverse sequence are both 0.4447:0.7224:1:1:0.7224:0.4447. The quarter wavelength conversion section 4 of the third transverse sequence, the quarter wavelength conversion section 4 of the fourth transverse sequence, the quarter wavelength conversion section 4 of the fifth transverse sequence and the quarter wavelength transformation section 4 of the sixth transverse sequence The excitation current amplitude ratios of one of the wavelength conversion sections 4 are all in the order of 0.4235:0.5937:0.8317:1:1:0.8317:0.5937:0.4235.

Similarly, based on the Taylor synthesis method, the excitation current amplitude ratio sequence of the eight main quarter-wavelength impedance converters 6 on the main transmission line 7 is 0.4235:0.5937:0.8317:1:1:0.8317:0.5937:0.4235, that is, based on The excitation current amplitude ratio sequence can be obtained by directly calculating the impedances of the eight main quarter-wavelength impedance converters 6 according to the method in the prior art.

As shown in Figure 5, the gain simulation results of the circular aperture array antenna of the present invention show that the gain is greater than 22dB, and the side lobe level is less than -24dB. The utility model can be widely used in the field of microwave communication as a front-end device for sending or receiving electromagnetic waves. The waveguide-coaxial feeding method can solve the problem that the conventional feeding method of antenna products cannot meet the performance requirements of the radiation direction due to the limitation of the structural size. And optimizing the unit feed current of the conventional antenna feed method makes the sidelobe gain suppression index better, and it is also conducive to rational use of space in product design to reduce costs, reduce debugging difficulty, increase product qualification rate and good stability. The Taylor synthesis method is used to form an array, which reduces the side lobe level. Compared with the 8x6 microstrip array antenna, the utility model removes two microstrip antenna units on the left and right sides of the first row (based on the Y-axis direction), and removes one microstrip antenna unit from the second row. Similarly, the seventh Two microstrip antenna units are removed from the left and right sides of the row, and one microstrip antenna unit is removed from the eighth row, which reduces the number of microstrip antenna units and enables it to become a circular-caliber microstrip array antenna. The reduction reduces the antenna area.

The basic principles, main features and advantages of the present utility model have been shown and described above. Those skilled in the industry should understand that the utility model is not limited by the above-mentioned embodiments. The above-mentioned embodiments and descriptions describe only the principle of the utility model. There will be various changes and improvements, and these changes and improvements all fall within the scope of the claimed utility model. The protection scope required by the utility model is defined by the appended claims and their equivalents.

Claims (8)

1. A microstrip array antenna, comprising a dielectric substrate (1) and a conductive ground plate (3) installed on the lower surface of the dielectric substrate (1), characterized in that: The dielectric substrate (1) is circular, and 52 microstrip antenna units (2) are arranged on the upper surface of the dielectric substrate (1), and the 52 microstrip antenna units (2) are all connected with a quarter-wavelength conversion Section (4), 52 microstrip antenna units (2) are divided into eight horizontal sequences on the dielectric substrate (1) based on the Y-axis direction of the dielectric substrate (1), and the microstrip antenna units (2) in each horizontal sequence The quarter-wavelength conversion section (4) is connected by a three-quarter-wavelength transmission line (5), the first transverse sequence and the eighth transverse sequence both have four microstrip antenna units (2), the second transverse sequence and The seventh transverse sequence has 6 microstrip antenna units (2), and the third transverse sequence, the fourth transverse sequence, the fifth transverse sequence and the sixth transverse sequence each have 8 microstrip antenna units (2); The central points of the three-quarter wavelength transmission lines (5) of the eight transverse sequences are all connected in series with the main quarter-wavelength impedance converter (6), and the eight main quarter-wavelength impedance converters (6) pass through the main The transmission lines (7) are connected in series to form a feed network, and the waveguide-coaxial backfeed connector (8) is installed at the center of the main transmission line (7). 2. A microstrip array antenna according to claim 1, characterized in that: the waveguide-coaxial backfeed joint (8) includes a standard waveguide (9), and the standard waveguide (9) is embedded with an L-shaped The coaxial probe (10), the L-shaped coaxial probe (10) is embedded in the standard waveguide (9) half the wavelength of the guided wave and then connected to the side where the broad side of the standard waveguide (9) is located. 3. A microstrip array antenna according to claim 1, characterized in that: the quarter-wavelength conversion section (4) of the first transverse sequence and the quarter-wavelength conversion section of the eighth transverse sequence (4) The excitation current amplitude ratios are all in the order of 0.5096:1:1:0.5096, the quarter-wavelength conversion segment (4) of the second transverse sequence and the quarter-wavelength conversion segment (4) of the seventh transverse sequence ( 4) The excitation current amplitude ratios are all in the order of 0.4447:0.7224:1:1:0.7224:0.4447, the quarter wavelength conversion section (4) of the third transverse sequence, the quarter wavelength of the fourth transverse sequence The excitation current amplitude ratio sequence of the conversion section (4), the quarter-wavelength conversion section (4) of the fifth transverse sequence and the quarter-wavelength conversion section (4) of the sixth transverse sequence is all 0.4235:0.5937: 0.8317:1:1:0.8317:0.5937:0.4235. 4. A microstrip array antenna according to claim 1, characterized in that: the excitation current amplitude ratio sequence of the eight main quarter-wavelength impedance converters (6) on the main transmission line (7) is 0.4235:0.5937:0.8317:1:1:0.8317:0.5937:0.4235. 5. A microstrip array antenna according to claim 1, characterized in that: the dielectric substrate (1) has a thickness of 10 mil, a dielectric constant of 2.94, and a loss tangent angle δ of 0.0012. 6. The microstrip array antenna according to claim 1, characterized in that: the diameter of the dielectric substrate (1) is 50 mm. 7. A microstrip array antenna according to claim 1, characterized in that the distance between the 52 microstrip antenna units (2) is one waveguide wavelength. 8. A microstrip array antenna according to claim 2, characterized in that: the wide side of the standard waveguide (9) is 5.69 mm, and the narrow side is 2.845 mm.