Hybrid omnidirectional circularly polarized planar helical antenna and communication equipment

Abstract

The present invention discloses a hybrid omnidirectional circularly polarized planar helical antenna and communication equipment, wherein the antenna comprises an upper and lower part, each part comprises two first planar helical antenna units and one second planar helical antenna unit, the two first planar helical antenna units and one second planar helical antenna unit are connected in series, the first planar helical antenna unit and the second planar helical antenna unit are both formed by surrounding a double helical structure, and a feeding port is provided between the two first planar helical antenna units closest to the upper and lower parts. The present invention has the characteristics of omnidirectional circularly polarized radiation, low profile, small size, easy integration, etc.

Description

Technical Field

[0001] The invention relates to a helical antenna, in particular to a hybrid omnidirectional circularly polarized planar helical antenna and communication equipment, belonging to the technical field of antennas. Background Art

[0002] In wireless local area networks (WLANs), circularly polarized antennas that radiate electromagnetic waves omnidirectionally have broad application prospects. Omnidirectional radiation can make the antenna beam cover a range of 360°, which can effectively increase the signal coverage range; circularly polarized antennas can effectively receive electromagnetic waves of different polarizations, suppress multipath transmission, and make them more resistant to interference in multipath propagation environments. At the same time, as the design of modern electronic equipment gradually tends to be portable and highly integrated, the miniaturization and planarization of antennas have become the general trend of the development of modern communication technology. By miniaturizing and planarizing antennas, the space occupied by antennas can be reduced, allowing antennas to be directly integrated into circuit boards, expanding the application range of antennas, reducing antenna costs, and also having the characteristics of low energy consumption.

[0003] The spiral structure is a common antenna for circular polarization. The radiation characteristics are divided into two types: axial mode radiation and normal mode radiation. When the circumference of the spiral is about one wavelength, that is, the diameter of the spiral is from one quarter wavelength to one half wavelength (D / λ=0.25-0.5), the spiral antenna works in the axial mode radiation state, and the antenna is directional radiation; when the circumference of one turn of the spiral is less than half a wavelength, that is, the spiral diameter is less than 0.18 wavelengths (D / λ<0.18), the spiral antenna works in the normal mode radiation state, and the antenna is omnidirectional radiation. It can be seen that the axial mode spiral antenna is larger in size, while the normal mode spiral is smaller in size, which is conducive to realizing the omnidirectional circular polarization radiation characteristics and miniaturization of the antenna.

[0004] Most of the existing circularly polarized helical antennas are three-dimensional structures and work in an axial mode. They have problems such as large size and inability to radiate omnidirectionally. Existing planar helical antennas are also mostly directional in radiation and have a high cross-section. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and provide a hybrid omnidirectional circularly polarized planar helical antenna, which has the characteristics of omnidirectional circularly polarized radiation, low profile, small size, easy integration, etc.

[0006] Another object of the present invention is to provide a communication device comprising the above-mentioned hybrid omnidirectional circularly polarized planar helical antenna.

[0007] The purpose of the present invention can be achieved by adopting the following technical solutions:

[0008] A hybrid omnidirectional circularly polarized planar helical antenna comprises an upper and lower part, each part comprises two first planar helical antenna units and one second planar helical antenna unit, the two first planar helical antenna units and the second planar helical antenna unit are connected in series, the first planar helical antenna unit and the second planar helical antenna unit are both formed by surrounding a double helical structure, and a feeding port is provided between the two first planar helical antenna units closest to each other in the upper and lower parts.

[0009] Furthermore, the first planar helical antenna unit and the second planar helical antenna unit both include multiple sections of metal layers and multiple metal vias, and the first planar helical antenna unit and the second planar helical antenna unit are both composed of multiple sections of metal layers and multiple metal vias surrounded by a double helical structure.

[0010] Furthermore, it also includes two first dielectric substrates and one second dielectric substrate, wherein the two first dielectric substrates are laminated together with the second dielectric substrate sandwiched between them;

[0011] The metal layers of the first planar helical antenna unit are respectively arranged on the upper and lower surfaces of the second dielectric substrate, and the metal layers of the first planar helical antenna unit on the upper and lower surfaces of the second dielectric substrate are connected through metal vias;

[0012] The metal layers of the second planar helical antenna unit are respectively arranged on the upper surface of the first first dielectric substrate and the lower surface of the second first dielectric substrate, and the metal layer on the upper surface of the first first dielectric substrate and the metal layer on the lower surface of the second first dielectric substrate are connected through metal vias;

[0013] The metal layer on the upper surface of the second dielectric substrate of the first planar spiral antenna unit is connected to the metal layer on the upper surface of the first dielectric substrate of the second planar spiral antenna unit through a metal via, and the metal layer on the lower surface of the second dielectric substrate of the first planar spiral antenna unit is connected to the metal layer on the lower surface of the second dielectric substrate of the second planar spiral antenna unit through a metal via.

[0014] Furthermore, the length and width of the first dielectric substrate are the same as the length and width of the second dielectric substrate, and the height of the first dielectric substrate is greater than the height of the second dielectric substrate.

[0015] Furthermore, the two sections of the double helix structure have opposite directions of rotation and the same helix width.

[0016] Furthermore, each spiral structure is a square spiral.

[0017] Furthermore, the first planar helical antenna unit and the second planar helical antenna unit have the same helical rotation direction and different helical widths, forming a hybrid normal mode helical structure.

[0018] Furthermore, the total circumference of one section of the double helical structure of the first planar helical antenna unit in the upper and lower parts is half the wavelength.

[0019] Furthermore, the circumference of one segment of the double helical structure of each second planar helical antenna unit is half the wavelength.

[0020] Another object of the present invention can be achieved by adopting the following technical solutions:

[0021] A communication device comprises the above-mentioned hybrid omnidirectional circularly polarized planar helical antenna.

[0022] The present invention has the following beneficial effects compared with the prior art:

[0023] 1. The present invention adopts a radiation structure of a hybrid normal mode spiral, which enables the amplitudes of the horizontal and vertical polarized waves radiated by the spiral antenna to be changed by adjusting the size parameters of different spiral structures to achieve the conditions of equal amplitude and 90° phase difference, thereby achieving better circularly polarized radiation. This can solve the problems of existing spiral antennas that are difficult to achieve circularly polarized omnidirectional radiation, large size, high profile, and difficult to integrate.

[0024] 2. The present invention adopts a method of constructing a planar spiral structure on a dielectric substrate through a metal layer and metal vias. This method enables the spiral antenna to work in a form of a lower cross-section while retaining structural characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0026] Figure 1 It is a three-dimensional perspective structural diagram of the hybrid omnidirectional circularly polarized planar helical antenna according to an embodiment of the present invention.

[0027] Figure 2 It is a cross-sectional structural diagram of a hybrid omnidirectional circularly polarized planar helical antenna according to an embodiment of the present invention.

[0028] Figure 3 It is a three-dimensional perspective structural diagram of the upper part of the hybrid omnidirectional circularly polarized planar helical antenna according to an embodiment of the present invention.

[0029] Figure 4 This is a top view of the upper portion of the hybrid omnidirectional circularly polarized planar helical antenna according to an embodiment of the present invention.

[0030] Figure 5 The figure is a general schematic diagram of the current flow of the hybrid omnidirectional circularly polarized planar helical antenna according to an embodiment of the present invention.

[0031] Figure 6 for Figure 5 Enlarged view of point A in the middle.

[0032] Figure 7 for Figure 5 Enlarged view of point B in the middle.

[0033] Figure 8 for Figure 5 Enlarged view of point C in the middle.

[0034] Fig. 9 : This is the radiation pattern of the hybrid omnidirectional circularly polarized planar helical antenna at 5.25 GHz according to an embodiment of the present invention.

[0035] Fig.10 1 is an axial ratio diagram of the XOY cross section of the hybrid omnidirectional circularly polarized planar helical antenna according to an embodiment of the present invention at 5.25 GHz.

[0036] Among them, 100 is a first planar helical antenna unit, 200 is a second planar helical antenna unit, 300 is a first dielectric substrate, 400 is a second dielectric substrate, 1 is a metal layer, 2 is a metal via, and 3 is a feeding port. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0038] Embodiment 1:

[0039] like Figure 1 to Figure 4 As shown, this embodiment provides a hybrid omnidirectional circularly polarized planar helical antenna, which includes two upper and lower parts, each of which includes two first planar helical antenna units 100 and one second planar helical antenna unit 200, and the two first planar helical antenna units 100 and one second planar helical antenna unit 200 are connected in series.

[0040] The first planar helical antenna unit 100 and the second planar helical antenna unit 200 are coaxially arranged in series in the manner shown in the figure, that is, the central axes of all the first planar helical antenna units 100 and the second planar helical antenna units 200 coincide, and the first planar helical antenna units 100 and the second planar helical antenna units 200 are both constructed with a double helix structure; specifically, the first planar helical antenna unit 100 and the second planar helical antenna unit 200 both include a multi-segment metal layer 1 and a plurality of metal vias 2, and the first planar helical antenna unit 100 and the second planar helical antenna unit 200 are both constructed with a multi-segment metal layer 1 and a plurality of metal vias 2 in a double helix structure, which structure can ensure that the radiation pattern of the antenna will not be tilted, so that it can perform circularly polarized radiation in the horizontal direction perpendicular to the axial direction.

[0041] Furthermore, it also includes two first dielectric substrates 300 and one second dielectric substrate 400, and the two first dielectric substrates 300 sandwich the second dielectric substrate 400 and overlap together; wherein the length and width of the first dielectric substrate 300 are the same as the length and width of the second dielectric substrate 400, and the height (thickness) of the first dielectric substrate 300 is greater than the height (thickness) of the second dielectric substrate 400.

[0042] In this embodiment, the metal layer 1 of the first planar helical antenna unit 100 is respectively disposed on the upper and lower surfaces of the second dielectric substrate 400 , and the metal layers 1 on the upper and lower surfaces of the second dielectric substrate 400 are connected through metal vias 2 .

[0043] In this embodiment, the metal layer 1 of the second planar helical antenna unit 200 is respectively arranged on the upper surface of the first first dielectric substrate 300 and the lower surface of the second first dielectric substrate 300, and the metal layer 1 on the upper surface of the first first dielectric substrate 300 and the metal layer 1 on the lower surface of the second first dielectric substrate 300 are connected through a metal via 2.

[0044] In this embodiment, the metal layer 1 on the upper surface of the second dielectric substrate 400 of the first planar helical antenna unit 100 is connected to the metal layer 1 on the upper surface of the first dielectric substrate 300 of the second planar helical antenna unit 200 through the metal via 2, and the metal layer 1 on the lower surface of the second dielectric substrate 400 of the first planar helical antenna unit 200 is connected to the metal layer 1 on the lower surface of the second dielectric substrate 300 of the second planar helical antenna unit 100 through the metal via 2.

[0045] Furthermore, the turn spacing g1 of the first planar helical antenna unit 100 and the turn spacing g2 of the second planar helical antenna unit 200 may be the same or different, that is, the planar helical antenna units may be arranged and distributed with equal or unequal spacing.

[0046] Furthermore, the length of the metal layer that constitutes the spiral and affects the size of the spiral cross-section perpendicular to the spiral axis is called the spiral width; the first planar spiral antenna unit and the second planar spiral antenna unit have the same spiral rotation direction and different spiral widths, forming a mixed normal mode spiral structure, that is, the antenna as a whole has only one spiral rotation direction, regardless of clockwise or counterclockwise, and the design criteria of the mixed normal mode spiral structure are the double helix structure of the upper and lower parts of the first planar spiral antenna unit 100 (four first planar spiral antenna units 100) wherein the total circumference of one section of the spiral structure is half a wavelength, and the double helix structure of each second planar spiral antenna unit wherein the circumference of one section of the spiral structure is half a wavelength; the two sections of the double helix structure have opposite rotation directions and the same spiral width, and each section of the spiral structure is a square spiral, which is different from a traditional circular spiral.

[0047] Specifically, each first planar helical antenna unit 100 has the same helical width D1, and each second planar helical antenna unit 200 has the same helical width D2, and D1 and D2 are different in size, forming a hybrid helical structure. Compared with the traditional helical structure, this structure has stronger radiation resistance and higher radiation efficiency. At the same time, in order to achieve circularly polarized radiation, the helical widths D1, D2 and turn spacings g1, g2 of the first planar helical antenna unit 100 and the second planar helical antenna unit 200 can be adjusted so that the total circumference of the four first planar helical antenna units 100 and the circumference of a single second planar helical antenna unit 200 are both about half a wavelength in length, so that the current flow direction in the four first planar helical antenna units 100 is opposite to the flow direction in the upper and lower second planar helical antenna units 200, such as Figures 5 to 8 As shown, the horizontal and vertical components of the radiation waves of the first planar helical antenna unit 100 and the second planar helical antenna unit 200 cancel each other out and balance each other, thereby achieving omnidirectional circularly polarized radiation.

[0048] Furthermore, a feeding port 3 is provided between the two first planar helical antenna units 100 that are closest to each other in the upper and lower parts. Specifically, a feeding port 3 is provided between the two metal layers between the two first planar helical antenna units 100 that are closest to each other in the upper and lower parts, and the length p2 of the metal layer 1 can be adjusted according to feeding requirements.

[0049] In this embodiment, the dimensions of the helical antenna structure are 28 mm in length × 5.8 mm in width × 3.81 mm in height (0.73 λg × 0.15 λg × 0.1 λg), wherein λg is 38.53 mm, the line width w of the metal layer 1 is 0.4 mm, and the radius r of the metal via 2 is 0.1 mm; the helical width D1 of the first planar helical antenna unit 100 is 1 mm, and the turn spacing g1 is 0.6 mm; the helical width D2 of the second planar helical antenna unit 200 is 5.4 mm, and the turn spacing g2 is 0.8 mm; the first dielectric substrate 300 and the second dielectric substrate 400 are both made of Rogers RT / duroid 5880 material, the size parameters of the first dielectric substrate 300 are 52.4mm×21.4mm×1.524mm in length×width×height, the size parameters of the second dielectric substrate 400 are 52.4mm×21.4mm×0.762mm in length×width×height, the width of the feeding port 3 is consistent with the thickness of the second dielectric substrate 400, which is 0.762mm, the length p1 is 0.4mm, and the length p2 of the two metal layers 2 above and below the feeding port 3 are both 2.2mm; the simulation results of the antenna of this embodiment are shown by Fig. 9 and Fig.10 As shown, Fig. 9 The radiation patterns of the antenna in the XOY plane and YOZ plane at 5.25 GHz indicate that the antenna achieves omnidirectional radiation in the XOY plane at 5.25 GHz. Fig.10 The axial ratio diagram of the antenna at 5.25 GHz shows that the axial ratio of the antenna within 360° at 5.25 GHz is less than 3 dB, and omnidirectional circularly polarized radiation can be achieved.

[0050] To summarize, the present invention adopts a hybrid normal mode spiral radiation structure, which enables the amplitudes of the horizontal and vertical polarized waves radiated by the spiral antenna to be changed by adjusting the dimensional parameters of different spiral structures to achieve the conditions of equal amplitude and 90° phase difference, thereby achieving better circularly polarized radiation. This can solve the problems of existing spiral antennas that are difficult to achieve circularly polarized omnidirectional radiation, large size, high cross-section, and difficult integration.

[0051] The above is only a preferred embodiment of the present invention, but the implementation of the present invention is not limited to the above embodiment. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A hybrid omnidirectional circularly polarized planar helical antenna, characterized in that: It comprises two parts, an upper part and an lower part, each part comprises two first planar spiral antenna units, a second planar spiral antenna unit, two first dielectric substrates and a second dielectric substrate, the two first planar spiral antenna units and the second planar spiral antenna unit are connected in series, the first planar spiral antenna unit and the second planar spiral antenna unit are both formed by surrounding a double spiral structure, a feeding port is provided between the two first planar spiral antenna units closest to each other in the upper and lower parts, and the two first dielectric substrates sandwich the second dielectric substrate and overlap each other; The first planar helical antenna unit and the second planar helical antenna unit both include multiple sections of metal layers and multiple metal vias, and the first planar helical antenna unit and the second planar helical antenna unit are both formed by the multiple sections of metal layers and the multiple metal vias surrounded by a double helical structure; The metal layers of the first planar helical antenna unit are respectively arranged on the upper and lower surfaces of the second dielectric substrate, and the metal layers on the upper and lower surfaces of the second dielectric substrate are connected through metal vias; The metal layers of the second planar helical antenna unit are respectively arranged on the upper surface of the first first dielectric substrate and the lower surface of the second first dielectric substrate, and the metal layer on the upper surface of the first first dielectric substrate and the metal layer on the lower surface of the second first dielectric substrate are connected through metal vias; The metal layer on the upper surface of the second dielectric substrate of the first planar spiral antenna unit is connected to the metal layer on the upper surface of the first dielectric substrate of the second planar spiral antenna unit through a metal via, and the metal layer on the lower surface of the second dielectric substrate of the first planar spiral antenna unit is connected to the metal layer on the lower surface of the second dielectric substrate of the second planar spiral antenna unit through a metal via.

2. The hybrid omnidirectional circularly polarized planar helical antenna according to claim 1, characterized in that: The length and width of the first dielectric substrate are the same as those of the second dielectric substrate, and the height of the first dielectric substrate is greater than that of the second dielectric substrate.

3. The hybrid omnidirectional circularly polarized planar helical antenna according to any one of claims 1 to 2, characterized in that: The first planar helical antenna unit and the second planar helical antenna unit have the same helical rotation direction and different helical widths, forming a hybrid normal mode helical structure.

4. The hybrid omnidirectional circularly polarized planar helical antenna according to any one of claims 1 to 2, characterized in that: The two sections of the double helix structure have opposite directions of rotation and the same helix width.

5. The hybrid omnidirectional circularly polarized planar helical antenna according to claim 4, characterized in that: Each spiral structure is a square spiral.

6. The hybrid omnidirectional circularly polarized planar helical antenna according to any one of claims 1 to 2, characterized in that: The total circumference of one section of the double helical structure of the first planar helical antenna unit in the upper and lower parts is half the wavelength.

7. The hybrid omnidirectional circularly polarized planar helical antenna according to any one of claims 1 to 2, characterized in that: The circumference of one segment of the double helical structure of each second planar helical antenna unit is one-half wavelength.

8. A communication device, characterized in that: It comprises the hybrid omnidirectional circularly polarized planar helical antenna as described in any one of claims 1 to 7.

Images