A compact tightly coupled ultra-wideband top-firing antenna

Abstract

The present invention relates to the field of antenna engineering technology, and in particular to a compact tightly coupled ultra-wideband top-firing antenna, comprising an uppermost dielectric substrate, an intermediate dielectric substrate and a lowermost dielectric substrate, the upper surface of the uppermost dielectric substrate being attached with two groups of radiating patch pairs forming left-right and upper-lower mirror symmetry, each radiating patch being etched with a U-shaped groove, a T-shaped power divider located on the upper surface of the lowermost dielectric substrate being connected in phase with the radiating patch pairs forming left-right mirror symmetry through a metal feeding probe, and the T-shaped power divider being connected in anti-phase with the radiating patch pairs forming upper-lower mirror symmetry through a dual-port parallel differential feeder. The present invention realizes a compact tightly coupled ultra-wideband top-firing antenna by adjusting the spacing between the radiating patches and the differential feeding structure, and the antenna provided by the present invention has an effective operating frequency band of 6.72-9.29 GHz, a bandwidth of 32.10% is obtained, and the gain within the frequency band is greater than 5 dBi, meeting the antenna requirements of existing communication systems.

Description

Technical Field

[0001] The invention relates to the technical field of antenna engineering, and in particular to a compact tightly coupled ultra-wideband top-firing antenna. Background Art

[0002] With the continuous development of modern communication systems, people have higher and higher requirements on the weight, volume and structure of communication equipment. Miniaturization and modularization have become the development trend of communication devices today. However, due to the close coupling between electronic components in miniaturized arrays, the mutual coupling effect is enhanced, which is bound to affect the overall performance of the device. Therefore, how to achieve a compact structure while ensuring performance has become a current research focus, and the research on compact antennas has also emerged.

[0003] In the Chinese standard "Part 15 of Requirements and Measurement Methods for Electromagnetic Compatibility of Wireless Communication Equipment: Ultra-Wideband (UWB) Communication Equipment", ultra-wideband technology is described as: "Technology used for short-range radio communications, which involves the useful generation and emission of radio frequency energy distributed over a very large frequency range, which may overlap with several bands allocated to radio communication services. The useful radiation generated by the antenna of equipment using ultra-wideband technology should be at least 500MHz / -10dB bandwidth". This technology appeared in the late 1950s and was officially used in the civilian market in 2002. Ultra-wideband has the advantages of low power consumption, strong resistance to external interference factors, high signal transmission efficiency, secure communication, and resistance to multipath fading. It can be widely used in scenarios such as precise positioning, vital signs detection, short-range communication, etc., to achieve intelligence, mobility and high confidentiality in the fields of transportation, medical care, and military. Therefore, as the core component of the ultra-wideband system, the antenna undoubtedly needs to have a wide enough bandwidth to meet the hardware foundation of the system.

[0004] As a low-profile directional radiating antenna, the microstrip patch antenna can have both ultra-wideband performance and high integration in different application devices. It is a more commonly used ultra-wideband antenna. Although the conventional microstrip patch antenna itself does not have broadband characteristics, the broadband technology research on microstrip patch antennas has been relatively mature. For example, etching gaps on the patch and / or ground plane, loading parasitic patches, improving the feeding structure, etc., can stimulate multiple resonant modes of the antenna, which are superimposed to form a broadband. However, due to the current complex structure of broadband microstrip antennas and the existence of shortcomings such as narrow bandwidth, it is difficult to meet the needs of existing communication systems for wider bandwidth antennas, so that the working bandwidth of microstrip patch antennas still needs to be further expanded. Therefore, it is urgent to design an antenna that combines the ultra-wideband, miniaturization and low profile of microstrip antennas. Summary of the invention

[0005] The present invention provides a compact tightly coupled ultra-wideband top-firing antenna, which solves the technical problem that the current microstrip patch antenna has a relatively complex structure and still has disadvantages such as narrow frequency band, and cannot meet the demand of existing communication systems for wider frequency band antennas.

[0006] In order to solve the above technical problems, the present invention provides a compact tightly coupled ultra-wideband top-firing antenna, comprising an antenna radiating body and a balun converter connected to the antenna radiating body, wherein the antenna radiating body comprises an uppermost dielectric substrate, an intermediate dielectric substrate and a lowermost dielectric substrate arranged in sequence from top to bottom, the upper surface of the uppermost dielectric substrate is attached with two groups of radiating patch pairs forming left-right mirror symmetry and top-bottom mirror symmetry, and the upper surface of the lowermost dielectric substrate is attached with a T-shaped power divider;

[0007] The T-shaped power divider is connected in phase with a pair of radiating patches forming left-right mirror symmetry through a metal feeding probe, and is connected in antiphase with a pair of radiating patches forming upper-lower mirror symmetry through a dual-port parallel differential feed line.

[0008] In a further embodiment, each group of radiation patch pairs includes two radiation patches, and each radiation patch is etched with a U-shaped groove.

[0009] In a further embodiment, a preset spacing is provided between the radiating patches.

[0010] In a further embodiment, the preset spacing is between five-sixteenths and three-eighths of the center frequency free space wavelength.

[0011] In a further embodiment, the balun converter includes a single-port microstrip line, a first metal probe, a Klopfenstein cone ground, a balun ground plate, and a second metal probe; wherein the first metal probe, the Klopfenstein cone ground, and the balun ground plate are arranged on the lower surface of the lowermost dielectric substrate;

[0012] The dual-port parallel differential feeder and the single-port microstrip line are impedance matched from the differential port to the single port through a first metal probe and a Klopfenstein taper;

[0013] The single-port microstrip line is connected to a rectangular copper sheet attached to the upper surface of the uppermost dielectric substrate through a second metal probe.

[0014] In a further embodiment, it also includes an antenna ground plate disposed on the lower surface of the lowermost dielectric substrate.

[0015] In a further embodiment, the uppermost dielectric substrate, the middle dielectric substrate and the lowermost dielectric substrate are all made of FR4 material.

[0016] In a further embodiment, the length and width of the antenna radiating body are both 20 mm, and the height is 1.9 mm.

[0017] In a further embodiment, the operating frequency band of the antenna radiating body is 6.72-9.29 GHz.

[0018] The present invention provides a compact tightly coupled ultra-wideband top-firing antenna, comprising two groups of radiating patch pairs that form left-right mirror symmetry and top-bottom mirror symmetry, arranged on the upper surface of the uppermost dielectric substrate, a T-shaped power divider on the upper surface of the lowermost dielectric substrate is connected in phase with the radiating patch pairs that form left-right mirror symmetry through a metal feeding probe, and the T-shaped power divider is connected in antiphase with the radiating patch pairs that form top-bottom mirror symmetry through a dual-port parallel differential feeder. Compared with the prior art, the method adopts U-shaped slot etching, differential feeding and tight coupling technology between components, and optimizes various structural parameters of the antenna, thereby obtaining good impedance matching between the antenna radiation body and the input and output ports, and realizing a tightly coupled ultra-wideband top-firing antenna with the advantages of ultra-wideband, miniaturization, and low profile. The ultra-wideband top-firing antenna provided by the present invention obtains a bandwidth of 32.10%, and the gain in the frequency band exceeds 5dBi, which meets the antenna requirements of the existing communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a side view of a tightly coupled ultra-wideband top-firing antenna provided by an embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of the upper surface of the uppermost dielectric substrate provided by an embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of the upper surface of the lowest dielectric substrate provided by an embodiment of the present invention;

[0022] Figure 4 is a schematic diagram of the lower surface of the lowest dielectric substrate provided by an embodiment of the present invention;

[0023] Figure 5 is a three-dimensional perspective view of a tightly coupled ultra-wideband top-firing antenna provided by an embodiment of the present invention;

[0024] Figure 6 It is a schematic diagram comparing the performance of a single-element antenna and a four-element antenna provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following specifically illustrates the implementation mode of the present invention in conjunction with the accompanying drawings. The embodiments are provided for illustrative purposes only and cannot be understood as limiting the present invention. The accompanying drawings are provided for reference and illustration only and do not constitute a limitation on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from the spirit and scope of the present invention.

[0026] refer to Figure 1 , an embodiment of the present invention provides a compact tightly coupled ultra-wideband top-firing antenna, such as Figure 1 As shown, it includes: an antenna radiating body and a balun converter connected to the antenna radiating body, the antenna radiating body includes an uppermost dielectric substrate 12, an intermediate dielectric substrate 13 and a lowermost dielectric substrate 14 arranged in sequence from top to bottom, wherein the uppermost dielectric substrate 12, the intermediate dielectric substrate 13 and the lowermost dielectric substrate 14 are all made of FR4 material.

[0027] In one embodiment, Figure 2 As shown, two groups of radiation patch pairs 1 are attached to the upper surface of the uppermost dielectric substrate 12 to form left-right mirror symmetry and top-bottom mirror symmetry. U-shaped grooves are etched on the two groups of mirror-symmetrical radiation patch pairs 1. In this embodiment, the radiation patches are distributed at a preset spacing, and the preset spacing is preferably set to five-sixteenths to three-eighths of the center frequency free space wavelength.

[0028] It should be noted that this embodiment optimizes parameters such as the size of the radiation patch, the position of the feed, the spacing between the patches, and the slot size, thereby widening the bandwidth of the antenna.

[0029] like Figure 3 As shown, the radiation patch pair 1 is connected to the T-shaped power divider 4 located on the upper surface of the lowest dielectric substrate 14 through the metal feeding probe 2; in this embodiment, the T-shaped power divider 4 is connected in phase with the radiation patch pair forming left-right mirror symmetry through the metal feeding probe 2 (the phase difference between the two radiation patches is 0°), and the T-shaped power divider 4 is connected in anti-phase with the radiation patch pair forming upper-lower mirror symmetry through the dual-port parallel differential feed line 5 (the phase difference between the two radiation patches is 180°).

[0030] This embodiment achieves bandwidth expansion through differential feeding technology, and at the same time adjusts the spacing between the left-right mirror-symmetrical radiating patch pairs and the upper-lower mirror-symmetrical radiating patch pairs to 5 / 16 to 3 / 8 times the wavelength, so that the radiating patches are tightly coupled, thereby greatly expanding the impedance bandwidth of the antenna.

[0031] In one embodiment, the balun converter includes a single-port microstrip line 6, a first metal probe 7, a Klopfenstein taper 8, a balun ground plate 9 and a second metal probe 10. Figure 4 As shown, the first metal probe 7 , the Klopfenstein cone ground 8 , and the balun ground plate 9 are all arranged on the lower surface of the lowest dielectric substrate 14 .

[0032] The dual-port parallel differential feeder and the single-port microstrip line are impedance matched from differential port to single port through a first metal probe 7 and a Klopfenstein cone 8; the single-port microstrip line 6 is connected to a rectangular copper sheet 11 attached to the upper surface of the uppermost dielectric substrate through a second metal probe 10 to connect other structures.

[0033] This embodiment realizes the conversion between the dual-port parallel differential feeder 5 and the single-port microstrip line 6 through a balun converter. The core is to adjust the electric field distribution and realize the continuity of grounding. The electric field at the dual-port parallel differential feeder is distributed between the two parallel differential feeders, and the phase difference is 180°. One of the parallel differential feeders is connected to the Klopfenstein conical ground 8 by connecting a metal probe 7, so that the electric field is gradually converted to be distributed between the single-port microstrip line and the floor. At the same time, the gradual floor structure ensures the continuity of grounding.

[0034] In this embodiment, an antenna ground plate is also provided on the lower surface of the bottommost dielectric substrate 14. This embodiment adopts the technology of "U-shaped" slot etching, differential feeding and close coupling between elements, and optimizes the structural parameters such as the size of the antenna's T-shaped power divider, parallel differential feeder and Klopfenstein conical ground, thereby obtaining good impedance matching between the antenna radiating body and the input / output port, and realizing a tightly coupled ultra-wideband top-firing antenna with the advantages of ultra-wideband, miniaturization, and low profile.

[0035] Figure 5 The three-dimensional perspective diagram of the tightly coupled ultra-wideband top-firing antenna shows that the antenna model provided in this embodiment has a length and width of 20 mm and a total thickness of only about 1.9 mm, with a small size and an extremely low profile. When the antenna receives a signal, the radiating patch pair 1 senses the radiated electromagnetic wave in the space, which passes through the metal feeding probe 2, the T-shaped power divider 4, the dual-port parallel differential feed line 5, the single-port microstrip line 6, the second metal probe 10 and the rectangular copper sheet 11 in sequence, and is connected to components of other structures through the rectangular copper sheet 11 to conduct the signal to other structures. When transmitting a signal, the path is opposite to the above-mentioned receiving signal path.

[0036] like Figure 6 As shown, the tight-coupled ultra-wideband top-firing antenna provided in this embodiment has an effective operating frequency band of 6.72-9.29 GHz (reaching a bandwidth of 32.10%), and a gain within the frequency band of greater than 5 dBi.

[0037] The embodiment of the present invention realizes a compact tightly coupled ultra-wideband top-firing antenna by adjusting the spacing between patches and the position of the feeding probe, and at the same time adopts a "U-shaped" slot etching and a differential feeding structure to widen the impedance bandwidth, so that the antenna radiation body and the input and output ports have good impedance matching. In order to facilitate application to existing communication equipment, the antenna is connected to a balun converter to realize the conversion between the differential port and the single port, so that the single output port can be easily compatible with existing communication equipment. In this embodiment, the entire antenna is 40mm long, 20mm wide, and only about 1.9mm high. The effective working frequency band is 6.72-9.29GHz, and a bandwidth of 32.10% is obtained. The gain within the frequency band exceeds 5dBi, which meets the requirements of the existing communication system for antennas, and has the advantages of ultra-wideband, miniaturization, and low profile. Under the premise that the conventional microstrip patch antenna has a bandwidth of only about 10%, the antenna proposed in the embodiment of the present invention can achieve nearly 40% in the test.

[0038] This embodiment provides a compact tightly coupled ultra-wideband top-firing antenna, wherein the antenna radiation body comprises an uppermost dielectric substrate, an intermediate dielectric substrate and a lowermost dielectric substrate arranged in sequence, the upper surface of the uppermost dielectric substrate is attached with two groups of radiation patch pairs forming left-right mirror symmetry and upper-lower mirror symmetry, and the upper surface of the lowermost dielectric substrate is attached with a T-shaped power divider; the T-shaped power divider is connected in phase with the radiation patch pairs forming left-right mirror symmetry through a metal feeding probe; the T-shaped power divider is connected in anti-phase with the radiation patch pairs forming upper-lower mirror symmetry through a dual-port parallel differential feed line, and the antenna radiation body is connected to a balun converter to achieve conversion between differential ports and single ports. Compared with the prior art, this embodiment adopts "U-shaped" slot etching, differential feeding structure and a balun converter connected to the line radiation body, which widens the impedance bandwidth and realizes conversion between differential ports and single ports, thereby realizing an effective working frequency band of 6.72-9.29GHz, reaching a bandwidth of 32.10%, and the gain within the frequency band is greater than 5dBi.

[0039] The above-mentioned embodiments only express several preferred implementation modes of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in the technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be regarded as the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be based on the protection scope of the claims.

Claims

1. A compact tightly coupled ultra-wideband top-firing antenna, characterized in that: The invention comprises an antenna radiation body and a balun converter connected to the antenna radiation body, wherein the antenna radiation body comprises an uppermost dielectric substrate, an intermediate dielectric substrate and a lowermost dielectric substrate arranged in sequence from top to bottom, and two groups of radiation patch pairs forming left-right mirror symmetry and upper-lower mirror symmetry are attached to the upper surface of the uppermost dielectric substrate, and U-shaped grooves are etched on the two groups of mirror-symmetrical radiation patch pairs, and a T-shaped power divider is attached to the upper surface of the lowermost dielectric substrate; The T-shaped power divider is connected in phase with a pair of radiating patches that form left-right mirror symmetry through a metal feeding probe, and the T-shaped power divider is connected in anti-phase with a pair of radiating patches that form upper-lower mirror symmetry through a dual-port parallel differential feed line; The balun converter comprises a single-port microstrip line, a first metal probe, a Klopfenstein conical ground, a balun ground plate and a second metal probe; wherein the first metal probe, the Klopfenstein conical ground and the balun ground plate are arranged on the lower surface of the lowest dielectric substrate; The dual-port parallel differential feeder and the single-port microstrip line are impedance matched from the differential port to the single port through a first metal probe and a Klopfenstein taper; The single-port microstrip line is connected to a rectangular copper sheet attached to the upper surface of the uppermost dielectric substrate through a second metal probe.

2. A compact tightly coupled ultra-wideband top-firing antenna as claimed in claim 1, characterized in that: Each radiation patch pair includes two radiation patches, and a U-shaped groove is etched on each radiation patch.

3. A compact tightly coupled ultra-wideband top-firing antenna as claimed in claim 2, characterized in that: The radiating patches are arranged with preset spacings between them.

4. A compact tightly coupled ultra-wideband top-firing antenna as claimed in claim 3, characterized in that: The preset spacing is between five-sixteenths and three-eighths of the free space wavelength of the center frequency.

5. A compact tightly coupled ultra-wideband top-firing antenna as claimed in claim 1, characterized in that: The invention also includes an antenna grounding plate arranged on the lower surface of the lowest dielectric substrate.

6. A compact tightly coupled ultra-wideband top-firing antenna as claimed in claim 1, characterized in that: The uppermost dielectric substrate, the middle dielectric substrate and the lowermost dielectric substrate are all made of FR4 material.

7. A compact tightly coupled ultra-wideband top-fire antenna as claimed in claim 1, characterized in that: The length and width of the antenna radiation body are both 20 mm, and the height is 1.9 mm.

8. A compact tightly coupled ultra-wideband top-fire antenna as claimed in claim 1, characterized in that: The operating frequency band of the antenna radiation body is 6.72-9.29 GHz.

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