5G-R frequency band microstrip antenna

Abstract

The invention relates to a 5G-R frequency band microstrip antenna which comprises a PCB dielectric substrate, a plurality of antenna oscillators, a plurality of rectangular coupling oscillators, a metal feeder line and a metal grounding structure. Antenna oscillators are arranged on the front surface and the back surface of the PCB dielectric substrate; the plurality of rectangular coupled oscillators are transversely arranged on the front surface of the PCB dielectric substrate in rows, and the metal feeder line is arranged on the front surface of the PCB dielectric substrate; and the metal grounding structure is arranged on the back surface of the PCB dielectric substrate. A special interdigital gap structure is arranged on the back face of the PCB dielectric substrate of the microstrip antenna, a special metal grounding structure is formed through connection of the rectangular metal connecting strip and the rectangular metal grounding unit, the working frequency band range covers the uplink and downlink working frequency bands of railway 5G-R, a vertical polarization working mode is achieved, the in-band gain is high, and the antenna performance is high. And the actual requirement of a railway 5G-R receiving and transmitting common antenna can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of railway communication antennas, and in particular to a 5G-R band microstrip antenna. Background Art

[0002] Microstrip antennas have the advantages of small size, low profile, and easy integration. With the advancement of antenna design technology, microstrip antennas are also developing towards smaller size, low profile, and high gain. The purpose is to increase gain and expand bandwidth while making the antenna smaller in size and profile.

[0003] 5G-R (full name: 5G-Railway) is a new generation of railway mobile communication system based on 5G technology, with the characteristics of ultra-large bandwidth, ultra-low latency, and massive connections. As a special industry antenna, the 5G-R antenna in the railway communication field needs to have an operating frequency band covering the frequency band required by 5G-R, that is, the uplink frequency band ranges from 1965MHz to 1975MHz, and the downlink frequency band ranges from 2155MHz to 2165MHz. The polarization mode of the antenna is vertical polarization, and the antenna should have a high gain. Therefore, the design difficulty of the miniaturized, low-profile 5G-R vertically polarized microstrip antenna is relatively high. Summary of the invention

[0004] The purpose of the present invention is to provide a 5G-R band microstrip antenna that meets the miniaturization, low profile, and high gain requirements of the 5G-R antenna and is suitable for deployment along railways and stations.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A 5G-R frequency band microstrip antenna, the microstrip antenna comprising a PCB dielectric substrate, a plurality of antenna elements, a plurality of rectangular coupling elements, a metal feed line and a metal grounding structure;

[0007] Antenna elements are arranged on the front and back sides of the PCB dielectric substrate;

[0008] The plurality of rectangular coupling oscillators are arranged in a row transversely on the front side of the PCB dielectric substrate, and the metal feed line is arranged on the front side of the PCB dielectric substrate;

[0009] The metal grounding structure is arranged on the back side of the PCB dielectric substrate.

[0010] Further, the metal grounding structure includes a plurality of interdigitated gap structures, a plurality of rectangular metal connecting strips and a rectangular metal grounding unit;

[0011] A plurality of the interdigitated gap structures are arranged in a row longitudinally on the back side of the PCB dielectric substrate, and are connected to a rectangular metal grounding unit through a plurality of the rectangular metal connecting strips.

[0012] Furthermore, two of the interdigital gap structures adjacent to each other in the longitudinal direction do not contact each other;

[0013] The ends of the interdigital gap structures have interdigital structures, and the interdigital structures of two longitudinally adjacent interdigital gap structures are arranged horizontally from left to right and do not contact each other.

[0014] Furthermore, two rectangular metal connecting strips are provided and arranged transversely on the back side of the PCB dielectric substrate;

[0015] One end of the two rectangular metal connecting strips is respectively connected to the two longitudinal ends of the plurality of interdigital gap structures arranged in a row in the longitudinal direction, and the other end is respectively connected to the two longitudinal ends of the rectangular metal grounding unit.

[0016] Furthermore, two longitudinal ends of the plurality of interdigital gap structures arranged in a longitudinal row are located at the edges of the PCB dielectric substrate;

[0017] The rectangular metal connecting strip is located at the edge of the PCB dielectric substrate.

[0018] Furthermore, both longitudinal ends of the rectangular metal grounding unit and a side away from the interdigital gap structure are located at the edge of the PCB dielectric substrate.

[0019] Furthermore, a longitudinal antenna element is arranged on the front and back sides of the PCB dielectric substrate, and the two antenna elements are arranged in an antipodal structure.

[0020] Furthermore, the metal feed line is arranged horizontally on the front side of the PCB dielectric substrate, one end of the metal feed line is located at the edge of the PCB dielectric substrate, and the other end is connected to the end of the antenna element.

[0021] Furthermore, on the front side of the PCB dielectric substrate, a plurality of the rectangular coupling elements and the metal feeding lines are respectively arranged on both sides of the antenna element.

[0022] Furthermore, on the back side of the PCB dielectric substrate, the metal grounding structure is located on a side of the antenna element corresponding to the rectangular coupling element.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention provides a 5G-R frequency band microstrip antenna. As a miniaturized, high-gain vertically polarized microstrip antenna in a microstrip form, its operating frequency band ranges from 1.95 GHz to 2.25 GHz, and its physical bandwidth is 300 MHz. The in-band gain of the antenna is greater than 3.5 dBi. The antenna's operating frequency band simultaneously covers the uplink and downlink operating frequency bands of railway 5G-R, and has a vertically polarized working mode, which can meet the actual needs of the railway 5G-R's transmit-receive shared antenna. 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, drawings of other embodiments can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a front structural diagram of the microstrip antenna in an embodiment of the present invention.

[0027] Figure 2 It is a structural diagram of the reverse side of the microstrip antenna in an embodiment of the present invention.

[0028] Figure 3 4 is a graph showing the S11 reflection coefficient of the microstrip antenna in an embodiment of the present invention.

[0029] Figure 4 is a gain curve diagram of the microstrip antenna in an embodiment of the present invention.

[0030] Figure 5 is an input impedance curve diagram of the microstrip antenna in an embodiment of the present invention.

[0031] Figure 6 It is the Smith chart of the microstrip antenna in the embodiment of the invention.

[0032] The symbols in the figure are:

[0033] 101 - a first rectangular coupling oscillator, 102 - a second rectangular coupling oscillator, 103 - a third rectangular coupling oscillator, 104 - a fourth rectangular coupling oscillator, 105 - a first antenna oscillator, 106 - a metal feed line;

[0034] 2-PCB dielectric substrate;

[0035] 301-first interdigital gap structure, 302-second interdigital gap structure, 303-third interdigital gap structure, 304-fourth interdigital gap structure, 305-fifth interdigital gap structure, 306-second antenna oscillator, 307-first rectangular metal connecting strip, 308-second rectangular metal connecting strip, 309-rectangular metal grounding unit, 31-metal grounding structure. DETAILED DESCRIPTION

[0036] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0037] In the description of the present invention, it is necessary to understand that the terms "front", "back", "longitudinal", "lateral", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. They may be described interchangeably when necessary, and therefore should not be understood as limitations on the present invention.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connection", "access", "arrangement" and the like should be understood in a broad sense, for example, they can be fixedly connected or arranged, or detachably connected or arranged, or integrally connected or arranged. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Meanwhile, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance. Of course, such objects can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0040] In a specific implementation, Figure 1 The direction from left to right is defined as landscape, and the direction from top to bottom is defined as portrait.

[0041] In order to cover the frequency band required by 5G-R, the present invention provides a miniaturized, vertically polarized 5G-R band microstrip antenna, which is more suitable for deployment along railways and stations and has a higher gain.

[0042] Specifically, the microstrip antenna includes a PCB (Printed Circuit Board) dielectric substrate 2 , a plurality of antenna elements, a plurality of rectangular coupling elements, a metal feed line 106 and a metal grounding structure 31 .

[0043] A longitudinal antenna element is arranged on the front and back sides of the PCB dielectric substrate 2, and the two antenna elements are arranged in an antipodal structure.

[0044] On the front of the PCB dielectric substrate 2, there are also arranged a plurality of rectangular coupling oscillators and a metal feed line 106. The plurality of rectangular coupling oscillators are arranged in a row horizontally on the front of the PCB dielectric substrate 2. The metal feed line 106 is arranged horizontally on the front of the PCB dielectric substrate 2, with one end located at the edge of the PCB dielectric substrate 2 and the other end connected to the end of the antenna oscillator. The plurality of rectangular coupling oscillators and the metal feed line 106 are arranged on both sides of the antenna oscillator.

[0045] A metal grounding structure 31 is also arranged on the back of the PCB dielectric substrate 2. The metal grounding structure 31 includes a plurality of interdigital gap structures, a plurality of rectangular metal connecting strips and a rectangular metal grounding unit 309. The plurality of interdigital gap structures are arranged in a longitudinal column on the back of the PCB dielectric substrate 2 and connected to the rectangular metal grounding unit 309 through a plurality of rectangular metal connecting strips. The metal grounding structure 31 is located on one side of the antenna element corresponding to the rectangular coupling element.

[0046] Specifically, two longitudinally adjacent interdigital gap structures do not contact each other. The ends of the interdigital gap structures have interdigital structures, and the interdigital structures of the two longitudinally adjacent interdigital gap structures are arranged horizontally from left to right and do not contact each other.

[0047] Two rectangular metal connecting strips are provided and arranged horizontally on the back of the PCB dielectric substrate 2. One end of the two rectangular metal connecting strips is respectively connected to the longitudinal ends of the multiple interdigital gap structures arranged in a longitudinal column, and the other end is respectively connected to the longitudinal ends of the rectangular metal grounding unit 309. The longitudinal ends of the multiple interdigital gap structures arranged in a longitudinal column are located at the edge of the PCB dielectric substrate 2, the rectangular metal connecting strips are located at the edge of the PCB dielectric substrate 2, and the longitudinal ends of the rectangular metal grounding unit 309 and the side away from the interdigital gap structure are all located at the edge of the PCB dielectric substrate 2.

[0048] Example:

[0049] like Figure 1 and Figure 2 In this embodiment, the PCB dielectric substrate 2 is rectangular.

[0050] The antenna element on the front of the PCB dielectric substrate 2 is the first antenna element 105, which is located at the lower left of the center of the front of the PCB dielectric substrate 2 and arranged vertically. The rectangular coupling element is arranged on the right side of the first antenna element 105, and there are four of them, namely the first rectangular coupling element 101, the second rectangular coupling element 102, the third rectangular coupling element 103 and the fourth rectangular coupling element 104, which have the same geometric parameters and are arranged in rows with equal spacing horizontally. Among them, the first rectangular coupling element 101 is spaced a certain distance from the first antenna element 105, and the fourth rectangular coupling element 104 is spaced a certain distance from the edge of the PCB dielectric substrate 2. The metal feed line 106 adopts a 50Ω metal feed line, which is located on the left side of the first antenna element 105 and arranged horizontally, with the left end located at the edge of the PCB dielectric substrate 2 and the right end connected to the top of the first antenna element 105.

[0051] The antenna element on the back of the PCB dielectric substrate 2 is the second antenna element 306, which is arranged in an antipodal structure with the first antenna element 105. The metal grounding structure 31 on the back of the PCB dielectric substrate 2 is located on the left side of the second antenna element 306, wherein there are five interdigital gap structures, namely the first interdigital gap structure 301, the second interdigital gap structure 302, the third interdigital gap structure 303, the fourth interdigital gap structure 304 and the fifth interdigital gap structure 305, which are arranged in a row in the vertical direction. The first interdigital gap structure 301 and the fifth interdigital gap structure 305 have the same geometric dimensions and are located at both ends in the vertical direction, and the second interdigital gap structure 302, the third interdigital gap structure 303 and the fourth interdigital gap structure 304 have the same geometric dimensions and are located in the middle of the row. The longitudinal lengths of the first interdigital gap structure 301 and the fifth interdigital gap structure 305 are greater than the longitudinal lengths of the second interdigital gap structure 302, the third interdigital gap structure 303 and the fourth interdigital gap structure 304, and the transverse widths of all interdigital gap structures are the same.

[0052] The bottom of the first interdigital gap structure 301 has an interdigital structure, the top of the fifth interdigital gap structure 305 has an interdigital structure, and the tops and bottoms of the second interdigital gap structure 302, the third interdigital gap structure 303, and the fourth interdigital gap structure 304 all have interdigital structures. Two interdigital gap structures adjacent in the longitudinal direction do not contact each other, and at the same time, the interdigital structures of two interdigital gap structures adjacent in the longitudinal direction are arranged horizontally from left to right and do not contact each other, forming four gaps in the array, and the geometric dimensions of all the gaps are the same.

[0053] The two rectangular metal connecting strips are respectively the first rectangular metal connecting strip 307 and the second rectangular metal connecting strip 308, which are located at the longitudinal edges of the PCB dielectric substrate 2. The rectangular metal grounding unit 309 is located on the left side of the back side of the PCB dielectric substrate 2, and fills the entire board surface on the left side. The first rectangular metal connecting strip 307, the second rectangular metal connecting strip 308, the rectangular metal grounding unit 309 and the cross-finger gap structure together form a frame-shaped rectangular structure.

[0054] In other embodiments, the number of rectangular coupling oscillators and the number of interdigital gap structures may also be adjusted according to actual conditions, and are not limited to the quantity specified in this embodiment.

[0055] The present invention arranges the above-mentioned special cross-finger gap structure on the back side of the PCB dielectric substrate 2 of the microstrip antenna, and connects it to the rectangular metal grounding unit 309 through a rectangular metal connecting strip to form a special metal grounding structure 31, which performs electromagnetic field coupling with the first antenna element 105 located on the front side of the PCB dielectric substrate 2 through the PCB dielectric substrate 2, and directly performs electromagnetic field coupling with the second antenna element 306 located on the back side of the PCB dielectric substrate 2.

[0056] The following is the performance verification of the microstrip antenna provided by the present invention for the working requirements of 5G-R:

[0057] like Figure 3 As shown in the figure, the reflection coefficient S11 of the microstrip antenna is less than -10dB in the range of 1.95GHz to 2.25GHz. The absolute bandwidth of the antenna reaches 300MHz, the relative bandwidth of the antenna reaches 14.3%, the central operating frequency of the antenna is 2.09GHz, and the return loss at the central frequency point of 2.09GHz reaches -56.97dB. The antenna meets the frequency band requirements of 1965MHz to 1975MHz for uplink and 2155MHz to 2165MHz for downlink required by the 5G-R scenario.

[0058] Figure 4 The antenna gain curve between 1.5GHz and 3GHz is shown. Figure 4 It can be seen that the antenna gain of the microstrip antenna is 3.74dB at the center frequency 1970MHz of the uplink frequency band 1965MHz to 1975MHz required by 5G-R, and the antenna gain is 3.52dB at the center frequency 2160MHz of the downlink frequency band 2155MHz to 2165MHz. The antenna has high gain in both the uplink and downlink frequency bands of 5G-R.

[0059] Figure 5 The input impedance curve of the microstrip antenna is shown in Figure 5It can be seen that the input impedance of the antenna at the center resonant frequency of 2.09GHz is 50.04 ohms, which is very close to the standard impedance of 50 ohms. Obviously, the antenna matches the impedance of 50 ohms very well, which also indirectly proves that Figure 3 The performance of the antenna reflection coefficient S11 within the operating frequency band shown is good.

[0060] Figure 6 This is the Smith chart of the microstrip antenna. By observing the Smith chart, it is easy to see whether the impedance matching of the antenna meets the requirements. The impedance on the Smith chart is expressed by normalized impedance, and the normalized impedance of the center point of the circle in the figure is 1. It represents the standard value of impedance of 50 ohms. Figure 6 It can be observed that the normalized impedance of the microstrip antenna at the center frequency of 2.09 GHz is 1.0001-0.0145i, and the impedance matching is very good.

[0061] The absolute bandwidth of the antenna proposed in the present invention is 300MHz, and it can operate in the frequency band of 1.95GHz to 2.25GHz. The center resonant frequency is 2.09GHz, and the relative bandwidth of the antenna is 14.3%. The return loss of the antenna at the center resonant frequency of 2.09GHz is -56.97dB, and the input impedance is 50.04 ohms, which meets the operating frequency band requirements of 5G-R.

[0062] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A 5G-R band microstrip antenna, characterized in that: The microstrip antenna comprises a PCB dielectric substrate, a plurality of antenna elements, a plurality of rectangular coupling elements, a metal feed line and a metal grounding structure; Antenna elements are arranged on the front and back sides of the PCB dielectric substrate; The plurality of rectangular coupling oscillators are arranged in a row transversely on the front side of the PCB dielectric substrate, and the metal feed line is arranged on the front side of the PCB dielectric substrate; The metal grounding structure is arranged on the back side of the PCB dielectric substrate.

2. A 5G-R band microstrip antenna according to claim 1, characterized in that: The metal grounding structure includes a plurality of interdigitated gap structures, a plurality of rectangular metal connecting strips and a rectangular metal grounding unit; A plurality of the interdigitated gap structures are arranged in a row longitudinally on the back side of the PCB dielectric substrate, and are connected to a rectangular metal grounding unit through a plurality of the rectangular metal connecting strips.

3. A 5G-R band microstrip antenna according to claim 2, characterized in that: Two longitudinally adjacent interdigital gap structures do not contact each other; The ends of the interdigital gap structures have interdigital structures, and the interdigital structures of two longitudinally adjacent interdigital gap structures are arranged horizontally from left to right and do not contact each other.

4. The 5G-R band microstrip antenna according to claim 3, characterized in that: The rectangular metal connecting strips are provided with two and are arranged transversely on the back side of the PCB dielectric substrate; One end of the two rectangular metal connecting strips is respectively connected to the two longitudinal ends of the plurality of interdigital gap structures arranged in a row in the longitudinal direction, and the other end is respectively connected to the two longitudinal ends of the rectangular metal grounding unit.

5. The 5G-R band microstrip antenna according to claim 4, characterized in that: The longitudinal ends of the plurality of interdigital gap structures arranged in a row are located at the edges of the PCB dielectric substrate; The rectangular metal connecting strip is located at the edge of the PCB dielectric substrate.

6. The 5G-R band microstrip antenna according to claim 5, characterized in that: Both longitudinal ends of the rectangular metal grounding unit and a side away from the interdigital gap structure are located at the edge of the PCB dielectric substrate.

7. The 5G-R band microstrip antenna according to claim 1, characterized in that: A longitudinal antenna element is arranged on the front and back sides of the PCB dielectric substrate, and the two antenna elements are arranged in an antipodal structure.

8. The 5G-R band microstrip antenna according to claim 7, characterized in that: The metal feed line is arranged horizontally on the front side of the PCB dielectric substrate, one end of the metal feed line is located at the edge of the PCB dielectric substrate, and the other end is connected to the end of the antenna element.

9. The 5G-R band microstrip antenna according to claim 8, characterized in that: On the front side of the PCB dielectric substrate, a plurality of rectangular coupling elements and the metal feeding line are respectively arranged on both sides of the antenna element.

10. The 5G-R band microstrip antenna according to claim 9, characterized in that: On the back side of the PCB dielectric substrate, the metal grounding structure is located at a side of the antenna element corresponding to the rectangular coupling element.

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