Coupled feed slot antenna applied to satellite navigation frequency band

Abstract

The utility model relates to the technical field of antennas, in particular to a coupled feed slot antenna applied to a satellite navigation frequency band, which comprises a medium bottom plate, a metal bottom surface arranged at the bottom of the medium bottom plate, an upper three-quarter feed ring, a lower three-quarter feed ring, a slot antenna structure, a coaxial probe and the like. According to the utility model, the radiation principle of a four-arm helical antenna is utilized, a slotted gap on a slot antenna structure is used as a radiator, and the radiator is connected with a feed network through a coupling feeder line, namely the feed network is formed by the upper three-quarter feed ring, the lower three-quarter feed ring and the inner and outer cores of the coaxial probe in a mutual relation manner; according to the utility model, a simple and efficient coupling feed mode is realized, so that the antenna can effectively realize circular polarization and effective radiation, and in addition, the antenna also has the characteristics of simple structure and easiness in production.

Description

Technical Field

[0001] The utility model relates to the technical field of antennas, and more particularly to a coupled-feed slot antenna applied to a satellite navigation frequency band. Background Art

[0002] Antennas, as core components in wireless communication systems, have a direct impact on the efficiency and stability of signal transmission. In complex electromagnetic environments, antenna design must not only consider basic radiation and reception capabilities but also optimize for interference factors in specific scenarios. Circularly polarized waves, with their unique properties—strong resistance to ionospheric and multipath interference—have become an indispensable choice in satellite communications, a field with extremely high signal quality requirements.

[0003] The traditional four-arm helical antenna, with its unique structural design and good circular polarization performance, has a place in the field of satellite communications. However, this antenna also has some limitations that cannot be ignored. First, its operating bandwidth is relatively narrow, which makes it difficult to meet the broadband transmission requirements of modern communication technology. Second, the processing precision of the metal spiral arms is high, which not only increases manufacturing costs but also limits the improvement of production efficiency and output. Utility Model Content

[0004] The purpose of the present invention is to solve the technical problems of the above-mentioned traditional four-arm helical antenna. The present invention provides a coupled-fed slot antenna for use in the satellite navigation frequency band. The coupled-fed slot antenna utilizes the radiation principle of the four-arm helical antenna and realizes circular polarization and effective radiation through a simple coupled-feeding method. The antenna has a simple structure and is easy to produce.

[0005] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0006] The utility model proposes a coupled feed slot antenna for use in satellite navigation frequency bands, comprising a dielectric base plate and a metal bottom surface arranged at the bottom of the dielectric base plate, wherein the antenna further comprises an upper three-quarter feed ring, a lower three-quarter feed ring, a slot antenna structure and a coaxial probe;

[0007] An upper three-quarters feed ring is printed on the top of the dielectric substrate, and a lower three-quarters feed ring is printed on the bottom of the dielectric substrate;

[0008] The centers of the upper three-quarter feed loop and the lower three-quarter feed loop are connected to the inner core and the outer core of the coaxial probe, respectively; or, the centers of the upper three-quarter feed loop and the lower three-quarter feed loop are connected to the outer core and the inner core of the coaxial probe, respectively, and the relationship between the upper three-quarter feed loop and the lower three-quarter feed loop is an orthogonal relationship. Through these relationships, a feeding network of the antenna is formed;

[0009] The slot antenna structure is arranged symmetrically around the top of the dielectric base plate;

[0010] There are 2N slot antenna structures, where N is 2, 3, or 4;

[0011] 2N slot antenna structures are grouped in pairs, with one group connected to the upper three-quarters feed ring and the other group connected to the lower three-quarters feed ring;

[0012] The slot antenna structure includes a dielectric side plate, a coupling feed line, a metal layer and a slotted slot;

[0013] The medium side plate is arranged on the top of the medium bottom plate;

[0014] A side surface of the dielectric side plate away from the upper three-quarters feed ring is a metal layer, and a side surface of the dielectric side plate close to the upper three-quarters feed ring is printed with a coupling feed line;

[0015] The metal layer is etched with slotted gaps that serve as radiators;

[0016] One end of the slot is open to the outer edge of the metal layer, and the other end is closed downward;

[0017] The coupling feed line is connected to the upper three-quarters feed ring or the lower three-quarters feed ring.

[0018] As a preferred technical solution of the present invention, the width of one end of the slot is gradually narrowed toward the opening direction.

[0019] As an optimal technical solution of the present invention, the slot openings on the 2N slot antenna structure are arranged in a clockwise or counterclockwise direction in the circumferential direction of the above three-quarters of the feed ring; if arranged clockwise, the antenna radiates left-handed polarized waves, and if arranged counterclockwise, the antenna radiates right-handed polarized waves.

[0020] As a preferred technical solution of the present invention, the opening of the slotted gap is tilted upward, with an inclination angle of 0-90° between the horizontal direction of the metal bottom surface and the tilt direction of the opening.

[0021] As a preferred technical solution of the present invention, the dielectric bottom plate and the dielectric side plates are both made of FR4 plates.

[0022] The beneficial effects of the utility model are as follows:

[0023] The utility model utilizes the radiation principle of the four-arm helical antenna, uses the slotted slot on the slot antenna structure as a radiator, and connects it to the feeding network through a coupling feed line, that is, the upper three-quarters feeding ring, the lower three-quarters feeding ring, and the inner and outer cores of the coaxial probe form a feeding network, which realizes a simple and efficient coupling feeding method, so that the antenna can effectively achieve circular polarization and effective radiation. In addition, the utility model also has the characteristics of simple structure and easy production. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural diagram of the present utility model.

[0025] Figure 2 It is a schematic diagram of the connection between the upper three-quarters feed ring and the lower three-quarters feed ring of the utility model.

[0026] Figure 3 It is a partial structural diagram of the slot antenna structure of the utility model.

[0027] Figure 4 This is a reflection coefficient simulation result diagram of an embodiment of the present utility model.

[0028] Figure 5 This is a diagram of the axial ratio simulation results of an embodiment of the present utility model.

[0029] Figure 6 This is a right-hand direction diagram of an embodiment of the present utility model.

[0030] Figure 7 Left-hand direction diagram of the embodiment of the present utility model.

[0031] Figure numerals: 1-dielectric bottom plate, 2-metal ground, 3-upper three-quarters feed ring, 4-lower three-quarters feed ring, 5-slot antenna structure, 51-dielectric side plate, 52-coupling feed line, 53-metal layer, 54-slotted gap, 6-coaxial probe. DETAILED DESCRIPTION

[0032] Reference Figure 1-3 As shown, the present invention proposes a coupled-feed slot antenna for use in satellite navigation frequency bands, comprising a dielectric base plate and a metal bottom surface disposed below the dielectric base plate (for isolating the antenna feed network from the environment below the antenna). The antenna also comprises an upper three-quarter feed ring, a lower three-quarter feed ring, a slot antenna structure, and a coaxial probe.

[0033] An upper three-quarters feed ring is printed on the top of the dielectric substrate, and a lower three-quarters feed ring is printed on the bottom of the dielectric substrate;

[0034] The centers of the upper three-quarter feed loop and the lower three-quarter feed loop are connected to the inner core and the outer core of the coaxial probe, respectively; or, the centers of the upper three-quarter feed loop and the lower three-quarter feed loop are connected to the outer core and the inner core of the coaxial probe, respectively, and the relationship between the upper three-quarter feed loop and the lower three-quarter feed loop is orthogonal (which means that they are staggered at an angle of 90 degrees in space to generate ideal circularly polarized radiation. In this way, the antenna can better resist multipath interference and ionospheric interference, thereby improving the reliability of the entire system). Through these relationships, the antenna feeding network is formed;

[0035] The slot antenna structure is arranged symmetrically around the top of the dielectric base plate;

[0036] There are 2N slot antenna structures, where N is 2, 3, or 4;

[0037] 2N slot antenna structures are grouped in pairs, with one group connected to the upper three-quarters feed ring and the other group connected to the lower three-quarters feed ring;

[0038] The slot antenna structure includes a dielectric side plate, a coupling feed line, a metal layer and a slotted slot;

[0039] The medium side plate is arranged on the top of the medium bottom plate;

[0040] A side surface of the dielectric side plate away from the upper three-quarters feed ring is a metal layer, and a side surface of the dielectric side plate close to the upper three-quarters feed ring is printed with a coupling feed line;

[0041] The metal layer is etched with slotted gaps that serve as radiators;

[0042] One end of the slot is open to the outer edge of the metal layer, and the other end is closed downward;

[0043] The coupling feed line is connected to the upper three-quarters feed ring or the lower three-quarters feed ring.

[0044] The width of one end of the slot is gradually narrowed toward the opening direction.

[0045] Among them, the slot openings on the 2N slot antenna structures are arranged in a clockwise or counterclockwise direction on the circumference of the above three-quarters of the feed ring; when arranged clockwise, the antenna radiates left-handed polarized waves, and when arranged counterclockwise, the antenna radiates right-handed polarized waves.

[0046] The opening of the slotted gap is tilted upward, and the tilt angle between the horizontal direction of the metal bottom surface and the tilt direction of the opening is set to 0-90 degrees.

[0047] Wherein, the dielectric bottom plate and dielectric side plates are both made of FR4 plates, which are low in cost.

[0048] Example: The following are all examples of four slot antenna structures:

[0049] Figure 4 This is a reflection coefficient simulation result diagram of an embodiment of the present utility model, wherein the horizontal axis is the frequency and the vertical axis is the antenna port reflection coefficient. Generally, the frequency band where the antenna port reflection coefficient is less than -10dB is considered to be its operating frequency band;

[0050] Figure 5 This is a diagram of the axial ratio simulation results of an embodiment of the present utility model, where the horizontal axis is the frequency and the vertical axis is the axial ratio of the antenna. Generally, when the axial ratio of the antenna is less than 3dB, the electromagnetic wave radiated by the antenna is considered to be a circularly polarized wave;

[0051] Figure 6 This is the right-hand directional pattern of the embodiment of the present utility model, where the radial coordinate is the gain, the angular coordinate is the elevation angle, and the elevation angle of 0° is directly above the antenna.

[0052] Figure 7 This is the left-hand direction diagram of the embodiment of the utility model, and its coordinates are the same as Figure 6 .

[0053] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all perspectives, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and range of equivalents of the claims be included in the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0054] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A coupled-feed slot antenna for use in a satellite navigation frequency band, comprising a dielectric base plate and a metal bottom surface disposed below the dielectric base plate, characterized in that: It also includes an upper three-quarters feed ring, a lower three-quarters feed ring, a slot antenna structure and a coaxial probe; An upper three-quarters feed ring is printed on the top of the dielectric substrate, and a lower three-quarters feed ring is printed on the bottom of the dielectric substrate; The centers of the upper three-quarter feed loop and the lower three-quarter feed loop are connected to the inner core and the outer core of the coaxial probe, respectively; or, the centers of the upper three-quarter feed loop and the lower three-quarter feed loop are connected to the outer core and the inner core of the coaxial probe, respectively, and the relationship between the upper three-quarter feed loop and the lower three-quarter feed loop is an orthogonal relationship, so as to form a feeding network of the antenna; The slot antenna structure is arranged symmetrically around the top of the dielectric base plate; There are 2N slot antenna structures, where N is 2, 3, or 4; 2N slot antenna structures are grouped in pairs, with one group connected to the upper three-quarters feed ring and the other group connected to the lower three-quarters feed ring; The slot antenna structure includes a dielectric side plate, a coupling feed line, a metal layer and a slotted slot; The medium side plate is arranged on the top of the medium bottom plate; A side surface of the dielectric side plate away from the upper three-quarters feed ring is a metal layer, and a side surface of the dielectric side plate close to the upper three-quarters feed ring is printed with a coupling feed line; The metal layer is etched with slotted gaps that serve as radiators; One end of the slot is open to the outer edge of the metal layer, and the other end is closed downward; The coupling feed line is connected to the upper three-quarters feed ring or the lower three-quarters feed ring.

2. The coupled-fed slot antenna for use in a satellite navigation frequency band according to claim 1, wherein: The width of one end of the slot is gradually narrowed toward the opening direction.

3. The coupled-fed slot antenna for use in a satellite navigation frequency band according to claim 1, wherein: The slot openings on the 2N slot antenna structures are arranged in a clockwise or counterclockwise direction on the three-quarters of the circumference of the feed ring; If it is set clockwise, the antenna radiates left-hand polarized waves, and if it is set counterclockwise, the antenna radiates right-hand polarized waves.

4. The coupled-fed slot antenna for use in a satellite navigation frequency band according to claim 1, wherein: The opening of the slotted gap is tilted upward, and the tilt angle between the horizontal direction of the metal bottom surface and the tilt direction of the opening is set to 0-90 degrees.

5. The coupled-fed slot antenna for use in a satellite navigation frequency band according to claim 1, wherein: The dielectric bottom plate and dielectric side plates are both FR4 plates.

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